* [PATCH 00/11] -tip Timekeeping changes for 2.6.36 @ 2010-07-14 0:56 John Stultz 2010-07-14 0:56 ` [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies John Stultz 0 siblings, 1 reply; 35+ messages in thread From: John Stultz @ 2010-07-14 0:56 UTC (permalink / raw) To: LKML; +Cc: John Stultz, Thomas Gleixner Hey Thomas, I just wanted to send you my pending queue of timekeeping change for 2.6.36. It would be nice to get these into the -tip tree for testing prior to the merge window. thanks -john CC: Thomas Gleixner <tglx@linutronix.de> John Stultz (11): x86: Fix vtime/file timestamp inconsistencies Implement timespec_add time: Kill off CONFIG_GENERIC_TIME powerpc: Simplify update_vsyscall powerpc: Cleanup xtime usage Fix update_vsyscall to provide wall_to_monotonic offset Convert um to use read_persistent_clock Cleanup hrtimer.c's direct access to wall_to_monotonic Make xtime and wall_to_monotonic static Convert common x86 clocksources to use clocksource_register_hz/khz Add __clocksource_updatefreq_hz/khz methods Documentation/feature-removal-schedule.txt | 10 ---- Documentation/kernel-parameters.txt | 3 +- arch/alpha/Kconfig | 4 -- arch/arm/Kconfig | 4 -- arch/avr32/Kconfig | 3 - arch/blackfin/Kconfig | 3 - arch/cris/Kconfig | 3 - arch/frv/Kconfig | 4 -- arch/h8300/Kconfig | 4 -- arch/ia64/Kconfig | 4 -- arch/ia64/kernel/time.c | 7 ++- arch/m32r/Kconfig | 3 - arch/m68k/Kconfig | 3 - arch/m68knommu/Kconfig | 4 -- arch/microblaze/Kconfig | 3 - arch/mips/Kconfig | 4 -- arch/mn10300/Kconfig | 3 - arch/parisc/Kconfig | 4 -- arch/powerpc/Kconfig | 3 - arch/powerpc/kernel/time.c | 61 ++++++++++------------ arch/s390/Kconfig | 3 - arch/s390/kernel/time.c | 8 ++-- arch/score/Kconfig | 3 - arch/sh/Kconfig | 3 - arch/sparc/Kconfig | 3 - arch/um/Kconfig.common | 4 -- arch/um/kernel/time.c | 13 +++-- arch/x86/Kconfig | 5 +-- arch/x86/kernel/hpet.c | 13 +++-- arch/x86/kernel/tsc.c | 6 +-- arch/x86/kernel/vsyscall_64.c | 17 ++++-- arch/xtensa/Kconfig | 3 - drivers/Makefile | 4 +- drivers/acpi/acpi_pad.c | 2 +- drivers/acpi/processor_idle.c | 2 +- drivers/clocksource/acpi_pm.c | 9 +--- drivers/misc/Kconfig | 4 +- include/linux/clocksource.h | 17 +++++- include/linux/time.h | 21 ++++++- kernel/hrtimer.c | 9 ++-- kernel/time.c | 16 ------ kernel/time/Kconfig | 4 +- kernel/time/clocksource.c | 33 +++++++++--- kernel/time/timekeeping.c | 79 +++++++--------------------- kernel/trace/Kconfig | 4 +- 45 files changed, 163 insertions(+), 259 deletions(-) ^ permalink raw reply [flat|nested] 35+ messages in thread
* [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies 2010-07-14 0:56 [PATCH 00/11] -tip Timekeeping changes for 2.6.36 John Stultz @ 2010-07-14 0:56 ` John Stultz 2010-07-14 0:56 ` [PATCH 02/11] Implement timespec_add John Stultz ` (2 more replies) 0 siblings, 3 replies; 35+ messages in thread From: John Stultz @ 2010-07-14 0:56 UTC (permalink / raw) To: LKML; +Cc: John Stultz, Jiri Olsa, Thomas Gleixner, Oleg Nesterov Due to vtime calling vgettimeofday(), its possible that an application could call time();create("stuff",O_RDRW); only to see the file's creation timestamp to be before the value returned by time. A similar way to reproduce the issue is to compare the vsyscall time() with the syscall time(), and observe ordering issues. The modified test case from Oleg Nesterov below can illustrate this: int main(void) { time_t sec1,sec2; do { sec1 = time(&sec2); sec2 = syscall(__NR_time, NULL); } while (sec1 <= sec2); printf("vtime: %d.000000\n", sec1); printf("time: %d.000000\n", sec2); return 0; } The proper fix is to make vtime use the same time value as current_kernel_time() (which is exported via update_vsyscall) instead of vgettime(). Thanks to Jiri Olsa for bringing up the issue and catching bugs in earlier verisons of this fix. Signed-off-by: John Stultz <johnstul@us.ibm.com> CC: Jiri Olsa <jolsa@redhat.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Oleg Nesterov <oleg@redhat.com> --- arch/x86/kernel/vsyscall_64.c | 11 ++++++++--- 1 files changed, 8 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index 1c0c6ab..dce0c3c 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -169,13 +169,18 @@ int __vsyscall(0) vgettimeofday(struct timeval * tv, struct timezone * tz) * unlikely */ time_t __vsyscall(1) vtime(time_t *t) { - struct timeval tv; + unsigned seq; time_t result; if (unlikely(!__vsyscall_gtod_data.sysctl_enabled)) return time_syscall(t); - vgettimeofday(&tv, NULL); - result = tv.tv_sec; + do { + seq = read_seqbegin(&__vsyscall_gtod_data.lock); + + result = __vsyscall_gtod_data.wall_time_sec; + + } while (read_seqretry(&__vsyscall_gtod_data.lock, seq)); + if (t) *t = result; return result; -- 1.6.0.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 02/11] Implement timespec_add 2010-07-14 0:56 ` [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies John Stultz @ 2010-07-14 0:56 ` John Stultz 2010-07-14 0:56 ` [PATCH 03/11] time: Kill off CONFIG_GENERIC_TIME John Stultz 2010-07-27 10:46 ` [tip:timers/clocksource] time: Implement timespec_add tip-bot for John Stultz 2010-07-14 2:40 ` [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies KOSAKI Motohiro 2010-07-27 10:45 ` [tip:timers/clocksource] " tip-bot for John Stultz 2 siblings, 2 replies; 35+ messages in thread From: John Stultz @ 2010-07-14 0:56 UTC (permalink / raw) To: LKML; +Cc: John Stultz, Thomas Gleixner After accidentally misusing timespec_add_safe, I wanted to make sure we don't accidently trip over that issue again, so I created a simple timespec_add() function which we can use to replace the instances of timespec_add_safe() that don't want the overflow detection. Signed-off-by: John Stultz <johnstul@us.ibm.com> CC: Thomas Gleixner <tglx@linutronix.de> --- include/linux/time.h | 16 ++++++++++++++++ kernel/time/timekeeping.c | 6 +++--- 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/include/linux/time.h b/include/linux/time.h index ea3559f..36b42f5 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -76,9 +76,25 @@ extern unsigned long mktime(const unsigned int year, const unsigned int mon, const unsigned int min, const unsigned int sec); extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec); + +/* + * timespec_add_safe assumes both values are positive and checks + * for overflow. It will return TIME_T_MAX if the reutrn would be + * smaller then either of the arguments. + */ extern struct timespec timespec_add_safe(const struct timespec lhs, const struct timespec rhs); + +static inline struct timespec timespec_add(struct timespec lhs, + struct timespec rhs) +{ + struct timespec ts_delta; + set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec, + lhs.tv_nsec + rhs.tv_nsec); + return ts_delta; +} + /* * sub = lhs - rhs, in normalized form */ diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index caf8d4d..623fe3d 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -579,9 +579,9 @@ static int timekeeping_resume(struct sys_device *dev) if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) { ts = timespec_sub(ts, timekeeping_suspend_time); - xtime = timespec_add_safe(xtime, ts); + xtime = timespec_add(xtime, ts); wall_to_monotonic = timespec_sub(wall_to_monotonic, ts); - total_sleep_time = timespec_add_safe(total_sleep_time, ts); + total_sleep_time = timespec_add(total_sleep_time, ts); } /* re-base the last cycle value */ timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); @@ -887,7 +887,7 @@ EXPORT_SYMBOL_GPL(getboottime); */ void monotonic_to_bootbased(struct timespec *ts) { - *ts = timespec_add_safe(*ts, total_sleep_time); + *ts = timespec_add(*ts, total_sleep_time); } EXPORT_SYMBOL_GPL(monotonic_to_bootbased); -- 1.6.0.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 03/11] time: Kill off CONFIG_GENERIC_TIME 2010-07-14 0:56 ` [PATCH 02/11] Implement timespec_add John Stultz @ 2010-07-14 0:56 ` John Stultz 2010-07-14 0:56 ` [PATCH 04/11] powerpc: Simplify update_vsyscall John Stultz 2010-07-27 10:46 ` [tip:timers/clocksource] time: Kill off CONFIG_GENERIC_TIME tip-bot for John Stultz 2010-07-27 10:46 ` [tip:timers/clocksource] time: Implement timespec_add tip-bot for John Stultz 1 sibling, 2 replies; 35+ messages in thread From: John Stultz @ 2010-07-14 0:56 UTC (permalink / raw) To: LKML; +Cc: John Stultz, Thomas Gleixner Now that all arches have been converted over to use generic time via clocksources or arch_gettimeoffset(), we can remove the GENERIC_TIME config option and simplify the generic code. Signed-off-by: John Stultz <johnstul@us.ibm.com> CC: Thomas Gleixner <tglx@linutronix.de> --- Documentation/kernel-parameters.txt | 3 +- arch/alpha/Kconfig | 4 -- arch/arm/Kconfig | 4 -- arch/avr32/Kconfig | 3 -- arch/blackfin/Kconfig | 3 -- arch/cris/Kconfig | 3 -- arch/frv/Kconfig | 4 -- arch/h8300/Kconfig | 4 -- arch/ia64/Kconfig | 4 -- arch/m32r/Kconfig | 3 -- arch/m68k/Kconfig | 3 -- arch/m68knommu/Kconfig | 4 -- arch/microblaze/Kconfig | 3 -- arch/mips/Kconfig | 4 -- arch/mn10300/Kconfig | 3 -- arch/parisc/Kconfig | 4 -- arch/powerpc/Kconfig | 3 -- arch/s390/Kconfig | 3 -- arch/score/Kconfig | 3 -- arch/sh/Kconfig | 3 -- arch/sparc/Kconfig | 3 -- arch/um/Kconfig.common | 4 -- arch/x86/Kconfig | 5 +-- arch/xtensa/Kconfig | 3 -- drivers/Makefile | 4 ++- drivers/acpi/acpi_pad.c | 2 +- drivers/acpi/processor_idle.c | 2 +- drivers/misc/Kconfig | 4 +- kernel/time.c | 16 ---------- kernel/time/Kconfig | 4 +- kernel/time/clocksource.c | 4 +- kernel/time/timekeeping.c | 55 ++-------------------------------- kernel/trace/Kconfig | 4 +- 33 files changed, 19 insertions(+), 159 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 82d6aeb..1014f91 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -73,7 +73,6 @@ parameter is applicable: MTD MTD (Memory Technology Device) support is enabled. NET Appropriate network support is enabled. NUMA NUMA support is enabled. - GENERIC_TIME The generic timeofday code is enabled. NFS Appropriate NFS support is enabled. OSS OSS sound support is enabled. PV_OPS A paravirtualized kernel is enabled. @@ -468,7 +467,7 @@ and is between 256 and 4096 characters. It is defined in the file clocksource is not available, it defaults to PIT. Format: { pit | tsc | cyclone | pmtmr } - clocksource= [GENERIC_TIME] Override the default clocksource + clocksource= Override the default clocksource Format: <string> Override the default clocksource and use the clocksource with the name specified. diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig index 3e2e540..b9647bb 100644 --- a/arch/alpha/Kconfig +++ b/arch/alpha/Kconfig @@ -47,10 +47,6 @@ config GENERIC_CALIBRATE_DELAY bool default y -config GENERIC_TIME - bool - default y - config GENERIC_CMOS_UPDATE def_bool y diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 98922f7..655b4ae 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -41,10 +41,6 @@ config SYS_SUPPORTS_APM_EMULATION config GENERIC_GPIO bool -config GENERIC_TIME - bool - default y - config ARCH_USES_GETTIMEOFFSET bool default n diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig index f2b3193..f515727 100644 --- a/arch/avr32/Kconfig +++ b/arch/avr32/Kconfig @@ -45,9 +45,6 @@ config GENERIC_IRQ_PROBE config RWSEM_GENERIC_SPINLOCK def_bool y -config GENERIC_TIME - def_bool y - config GENERIC_CLOCKEVENTS def_bool y diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig index f66294b..c88fd35 100644 --- a/arch/blackfin/Kconfig +++ b/arch/blackfin/Kconfig @@ -614,9 +614,6 @@ comment "Kernel Timer/Scheduler" source kernel/Kconfig.hz -config GENERIC_TIME - def_bool y - config GENERIC_CLOCKEVENTS bool "Generic clock events" default y diff --git a/arch/cris/Kconfig b/arch/cris/Kconfig index e25bf44..887ef85 100644 --- a/arch/cris/Kconfig +++ b/arch/cris/Kconfig @@ -20,9 +20,6 @@ config RWSEM_GENERIC_SPINLOCK config RWSEM_XCHGADD_ALGORITHM bool -config GENERIC_TIME - def_bool y - config GENERIC_CMOS_UPDATE def_bool y diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig index 4b5830b..16399bd 100644 --- a/arch/frv/Kconfig +++ b/arch/frv/Kconfig @@ -40,10 +40,6 @@ config GENERIC_HARDIRQS_NO__DO_IRQ bool default y -config GENERIC_TIME - bool - default y - config TIME_LOW_RES bool default y diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig index 53cc669..988b6ff 100644 --- a/arch/h8300/Kconfig +++ b/arch/h8300/Kconfig @@ -62,10 +62,6 @@ config GENERIC_CALIBRATE_DELAY bool default y -config GENERIC_TIME - bool - default y - config GENERIC_BUG bool depends on BUG diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index 9561082..8711d13 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -82,10 +82,6 @@ config GENERIC_CALIBRATE_DELAY bool default y -config GENERIC_TIME - bool - default y - config GENERIC_TIME_VSYSCALL bool default y diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig index 3a9319f..836abbb 100644 --- a/arch/m32r/Kconfig +++ b/arch/m32r/Kconfig @@ -44,9 +44,6 @@ config HZ int default 100 -config GENERIC_TIME - def_bool y - config ARCH_USES_GETTIMEOFFSET def_bool y diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig index 2e3737b..8030e24 100644 --- a/arch/m68k/Kconfig +++ b/arch/m68k/Kconfig @@ -59,9 +59,6 @@ config HZ int default 100 -config GENERIC_TIME - def_bool y - config ARCH_USES_GETTIMEOFFSET def_bool y diff --git a/arch/m68knommu/Kconfig b/arch/m68knommu/Kconfig index efeb603..2609c39 100644 --- a/arch/m68knommu/Kconfig +++ b/arch/m68knommu/Kconfig @@ -63,10 +63,6 @@ config GENERIC_CALIBRATE_DELAY bool default y -config GENERIC_TIME - bool - default y - config GENERIC_CMOS_UPDATE bool default y diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig index 76818f9..c96dab8 100644 --- a/arch/microblaze/Kconfig +++ b/arch/microblaze/Kconfig @@ -48,9 +48,6 @@ config GENERIC_IRQ_PROBE config GENERIC_CALIBRATE_DELAY def_bool y -config GENERIC_TIME - def_bool y - config GENERIC_TIME_VSYSCALL def_bool n diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index cdaae94..01c44cb 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -733,10 +733,6 @@ config GENERIC_CLOCKEVENTS bool default y -config GENERIC_TIME - bool - default y - config GENERIC_CMOS_UPDATE bool default y diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig index 1c4565a..444b9f9 100644 --- a/arch/mn10300/Kconfig +++ b/arch/mn10300/Kconfig @@ -46,9 +46,6 @@ config GENERIC_FIND_NEXT_BIT config GENERIC_HWEIGHT def_bool y -config GENERIC_TIME - def_bool y - config GENERIC_BUG def_bool y diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index 05a366a..907417d 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -66,10 +66,6 @@ config GENERIC_CALIBRATE_DELAY bool default y -config GENERIC_TIME - bool - default y - config TIME_LOW_RES bool depends on SMP diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 6506bf4..dd12626 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -29,9 +29,6 @@ config MMU config GENERIC_CMOS_UPDATE def_bool y -config GENERIC_TIME - def_bool y - config GENERIC_TIME_VSYSCALL def_bool y diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index bee1c0f..f0777a4 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -40,9 +40,6 @@ config ARCH_HAS_ILOG2_U64 config GENERIC_HWEIGHT def_bool y -config GENERIC_TIME - def_bool y - config GENERIC_TIME_VSYSCALL def_bool y diff --git a/arch/score/Kconfig b/arch/score/Kconfig index 55d413e..be4a155 100644 --- a/arch/score/Kconfig +++ b/arch/score/Kconfig @@ -55,9 +55,6 @@ config GENERIC_CALIBRATE_DELAY config GENERIC_CLOCKEVENTS def_bool y -config GENERIC_TIME - def_bool y - config SCHED_NO_NO_OMIT_FRAME_POINTER def_bool y diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index 573fca1..1d0a711 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -98,9 +98,6 @@ config GENERIC_CALIBRATE_DELAY config GENERIC_IOMAP bool -config GENERIC_TIME - def_bool y - config GENERIC_CLOCKEVENTS def_bool y diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig index 6f1470b..0011052 100644 --- a/arch/sparc/Kconfig +++ b/arch/sparc/Kconfig @@ -66,9 +66,6 @@ config BITS default 32 if SPARC32 default 64 if SPARC64 -config GENERIC_TIME - def_bool y - config ARCH_USES_GETTIMEOFFSET bool default y if SPARC32 diff --git a/arch/um/Kconfig.common b/arch/um/Kconfig.common index 0d207e7..7c8e277 100644 --- a/arch/um/Kconfig.common +++ b/arch/um/Kconfig.common @@ -55,10 +55,6 @@ config GENERIC_BUG default y depends on BUG -config GENERIC_TIME - bool - default y - config GENERIC_CLOCKEVENTS bool default y diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index dcb0593..546b610 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -72,9 +72,6 @@ config ARCH_DEFCONFIG default "arch/x86/configs/i386_defconfig" if X86_32 default "arch/x86/configs/x86_64_defconfig" if X86_64 -config GENERIC_TIME - def_bool y - config GENERIC_CMOS_UPDATE def_bool y @@ -2046,7 +2043,7 @@ config SCx200 config SCx200HR_TIMER tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" - depends on SCx200 && GENERIC_TIME + depends on SCx200 default y ---help--- This driver provides a clocksource built upon the on-chip diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig index ebe228d..0859bfd 100644 --- a/arch/xtensa/Kconfig +++ b/arch/xtensa/Kconfig @@ -48,9 +48,6 @@ config HZ int default 100 -config GENERIC_TIME - def_bool y - source "init/Kconfig" source "kernel/Kconfig.freezer" diff --git a/drivers/Makefile b/drivers/Makefile index 91874e0..ae47344 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -101,7 +101,9 @@ obj-y += firmware/ obj-$(CONFIG_CRYPTO) += crypto/ obj-$(CONFIG_SUPERH) += sh/ obj-$(CONFIG_ARCH_SHMOBILE) += sh/ -obj-$(CONFIG_GENERIC_TIME) += clocksource/ +ifndef CONFIG_ARCH_USES_GETTIMEOFFSET +obj-y += clocksource/ +endif obj-$(CONFIG_DMA_ENGINE) += dma/ obj-$(CONFIG_DCA) += dca/ obj-$(CONFIG_HID) += hid/ diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c index 446aced..b76848c 100644 --- a/drivers/acpi/acpi_pad.c +++ b/drivers/acpi/acpi_pad.c @@ -77,7 +77,7 @@ static void power_saving_mwait_init(void) power_saving_mwait_eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) | (highest_subcstate - 1); -#if defined(CONFIG_GENERIC_TIME) && defined(CONFIG_X86) +#if defined(CONFIG_X86) switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_AMD: case X86_VENDOR_INTEL: diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index b1b3856..0e562d0 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -259,7 +259,7 @@ int acpi_processor_resume(struct acpi_device * device) return 0; } -#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) +#if defined(CONFIG_X86) static void tsc_check_state(int state) { switch (boot_cpu_data.x86_vendor) { diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index 26386a9..5b9ba48 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -72,7 +72,7 @@ config ATMEL_TCLIB config ATMEL_TCB_CLKSRC bool "TC Block Clocksource" - depends on ATMEL_TCLIB && GENERIC_TIME + depends on ATMEL_TCLIB default y help Select this to get a high precision clocksource based on a @@ -240,7 +240,7 @@ config CS5535_MFGPT_DEFAULT_IRQ config CS5535_CLOCK_EVENT_SRC tristate "CS5535/CS5536 high-res timer (MFGPT) events" - depends on GENERIC_TIME && GENERIC_CLOCKEVENTS && CS5535_MFGPT + depends on GENERIC_CLOCKEVENTS && CS5535_MFGPT help This driver provides a clock event source based on the MFGPT timer(s) in the CS5535 and CS5536 companion chips. diff --git a/kernel/time.c b/kernel/time.c index 848b1c2..ba9b338 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -300,22 +300,6 @@ struct timespec timespec_trunc(struct timespec t, unsigned gran) } EXPORT_SYMBOL(timespec_trunc); -#ifndef CONFIG_GENERIC_TIME -/* - * Simulate gettimeofday using do_gettimeofday which only allows a timeval - * and therefore only yields usec accuracy - */ -void getnstimeofday(struct timespec *tv) -{ - struct timeval x; - - do_gettimeofday(&x); - tv->tv_sec = x.tv_sec; - tv->tv_nsec = x.tv_usec * NSEC_PER_USEC; -} -EXPORT_SYMBOL_GPL(getnstimeofday); -#endif - /* Converts Gregorian date to seconds since 1970-01-01 00:00:00. * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index 95ed429..f06a8a3 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -6,7 +6,7 @@ config TICK_ONESHOT config NO_HZ bool "Tickless System (Dynamic Ticks)" - depends on GENERIC_TIME && GENERIC_CLOCKEVENTS + depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS select TICK_ONESHOT help This option enables a tickless system: timer interrupts will @@ -15,7 +15,7 @@ config NO_HZ config HIGH_RES_TIMERS bool "High Resolution Timer Support" - depends on GENERIC_TIME && GENERIC_CLOCKEVENTS + depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS select TICK_ONESHOT help This option enables high resolution timer support. If your diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index f08e99c..c543d21 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -531,7 +531,7 @@ static u64 clocksource_max_deferment(struct clocksource *cs) return max_nsecs - (max_nsecs >> 5); } -#ifdef CONFIG_GENERIC_TIME +#ifndef CONFIG_ARCH_USES_GETTIMEOFFSET /** * clocksource_select - Select the best clocksource available @@ -577,7 +577,7 @@ static void clocksource_select(void) } } -#else /* CONFIG_GENERIC_TIME */ +#else /* !CONFIG_ARCH_USES_GETTIMEOFFSET */ static inline void clocksource_select(void) { } diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 623fe3d..73edd40 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -173,8 +173,6 @@ void timekeeping_leap_insert(int leapsecond) update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult); } -#ifdef CONFIG_GENERIC_TIME - /** * timekeeping_forward_now - update clock to the current time * @@ -376,52 +374,6 @@ void timekeeping_notify(struct clocksource *clock) tick_clock_notify(); } -#else /* GENERIC_TIME */ - -static inline void timekeeping_forward_now(void) { } - -/** - * ktime_get - get the monotonic time in ktime_t format - * - * returns the time in ktime_t format - */ -ktime_t ktime_get(void) -{ - struct timespec now; - - ktime_get_ts(&now); - - return timespec_to_ktime(now); -} -EXPORT_SYMBOL_GPL(ktime_get); - -/** - * ktime_get_ts - get the monotonic clock in timespec format - * @ts: pointer to timespec variable - * - * The function calculates the monotonic clock from the realtime - * clock and the wall_to_monotonic offset and stores the result - * in normalized timespec format in the variable pointed to by @ts. - */ -void ktime_get_ts(struct timespec *ts) -{ - struct timespec tomono; - unsigned long seq; - - do { - seq = read_seqbegin(&xtime_lock); - getnstimeofday(ts); - tomono = wall_to_monotonic; - - } while (read_seqretry(&xtime_lock, seq)); - - set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, - ts->tv_nsec + tomono.tv_nsec); -} -EXPORT_SYMBOL_GPL(ktime_get_ts); - -#endif /* !GENERIC_TIME */ - /** * ktime_get_real - get the real (wall-) time in ktime_t format * @@ -784,10 +736,11 @@ void update_wall_time(void) return; clock = timekeeper.clock; -#ifdef CONFIG_GENERIC_TIME - offset = (clock->read(clock) - clock->cycle_last) & clock->mask; -#else + +#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET offset = timekeeper.cycle_interval; +#else + offset = (clock->read(clock) - clock->cycle_last) & clock->mask; #endif timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift; diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 8b1797c..7531dda 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -153,7 +153,7 @@ config IRQSOFF_TRACER bool "Interrupts-off Latency Tracer" default n depends on TRACE_IRQFLAGS_SUPPORT - depends on GENERIC_TIME + depends on !ARCH_USES_GETTIMEOFFSET select TRACE_IRQFLAGS select GENERIC_TRACER select TRACER_MAX_TRACE @@ -175,7 +175,7 @@ config IRQSOFF_TRACER config PREEMPT_TRACER bool "Preemption-off Latency Tracer" default n - depends on GENERIC_TIME + depends on !ARCH_USES_GETTIMEOFFSET depends on PREEMPT select GENERIC_TRACER select TRACER_MAX_TRACE -- 1.6.0.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 04/11] powerpc: Simplify update_vsyscall 2010-07-14 0:56 ` [PATCH 03/11] time: Kill off CONFIG_GENERIC_TIME John Stultz @ 2010-07-14 0:56 ` John Stultz 2010-07-14 0:56 ` [PATCH 05/11] powerpc: Cleanup xtime usage John Stultz ` (2 more replies) 2010-07-27 10:46 ` [tip:timers/clocksource] time: Kill off CONFIG_GENERIC_TIME tip-bot for John Stultz 1 sibling, 3 replies; 35+ messages in thread From: John Stultz @ 2010-07-14 0:56 UTC (permalink / raw) To: LKML; +Cc: John Stultz, Anton Blanchard, Paul Mackerras, Thomas Gleixner Currently powerpc's update_vsyscall calls an inline update_gtod. However, both are straightforward, and there are no other users, so this patch merges update_gtod into update_vsyscall. Compiles, but otherwise untested. Cc: Anton Blanchard <anton@samba.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <johnstul@us.ibm.com> --- arch/powerpc/kernel/time.c | 55 ++++++++++++++++++++------------------------ 1 files changed, 25 insertions(+), 30 deletions(-) diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 0441bbd..6fcd648 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -423,30 +423,6 @@ void udelay(unsigned long usecs) } EXPORT_SYMBOL(udelay); -static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec, - u64 new_tb_to_xs) -{ - /* - * tb_update_count is used to allow the userspace gettimeofday code - * to assure itself that it sees a consistent view of the tb_to_xs and - * stamp_xsec variables. It reads the tb_update_count, then reads - * tb_to_xs and stamp_xsec and then reads tb_update_count again. If - * the two values of tb_update_count match and are even then the - * tb_to_xs and stamp_xsec values are consistent. If not, then it - * loops back and reads them again until this criteria is met. - * We expect the caller to have done the first increment of - * vdso_data->tb_update_count already. - */ - vdso_data->tb_orig_stamp = new_tb_stamp; - vdso_data->stamp_xsec = new_stamp_xsec; - vdso_data->tb_to_xs = new_tb_to_xs; - vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; - vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; - vdso_data->stamp_xtime = xtime; - smp_wmb(); - ++(vdso_data->tb_update_count); -} - #ifdef CONFIG_SMP unsigned long profile_pc(struct pt_regs *regs) { @@ -876,7 +852,7 @@ static cycle_t timebase_read(struct clocksource *cs) void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, u32 mult) { - u64 t2x, stamp_xsec; + u64 new_tb_to_xs, new_stamp_xsec; if (clock != &clocksource_timebase) return; @@ -887,11 +863,30 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, /* XXX this assumes clock->shift == 22 */ /* 4611686018 ~= 2^(20+64-22) / 1e9 */ - t2x = (u64) mult * 4611686018ULL; - stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC; - do_div(stamp_xsec, 1000000000); - stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC; - update_gtod(clock->cycle_last, stamp_xsec, t2x); + new_tb_to_xs = (u64) mult * 4611686018ULL; + new_stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC; + do_div(new_stamp_xsec, 1000000000); + new_stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC; + + /* + * tb_update_count is used to allow the userspace gettimeofday code + * to assure itself that it sees a consistent view of the tb_to_xs and + * stamp_xsec variables. It reads the tb_update_count, then reads + * tb_to_xs and stamp_xsec and then reads tb_update_count again. If + * the two values of tb_update_count match and are even then the + * tb_to_xs and stamp_xsec values are consistent. If not, then it + * loops back and reads them again until this criteria is met. + * We expect the caller to have done the first increment of + * vdso_data->tb_update_count already. + */ + vdso_data->tb_orig_stamp = clock->cycle_last; + vdso_data->stamp_xsec = new_stamp_xsec; + vdso_data->tb_to_xs = new_tb_to_xs; + vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; + vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; + vdso_data->stamp_xtime = xtime; + smp_wmb(); + ++(vdso_data->tb_update_count); } void update_vsyscall_tz(void) -- 1.6.0.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 05/11] powerpc: Cleanup xtime usage 2010-07-14 0:56 ` [PATCH 04/11] powerpc: Simplify update_vsyscall John Stultz @ 2010-07-14 0:56 ` John Stultz 2010-07-14 0:56 ` [PATCH 06/11] Fix update_vsyscall to provide wall_to_monotonic offset John Stultz 2010-07-27 10:47 ` [tip:timers/clocksource] powerpc: Cleanup xtime usage tip-bot for John Stultz 2010-07-27 10:46 ` [tip:timers/clocksource] powerpc: Simplify update_vsyscall tip-bot for John Stultz 2010-07-27 23:41 ` Paul Mackerras 2 siblings, 2 replies; 35+ messages in thread From: John Stultz @ 2010-07-14 0:56 UTC (permalink / raw) To: LKML; +Cc: John Stultz, Paul Mackerras, Anton Blanchard, Thomas Gleixner This removes powerpc's direct xtime usage, allowing for further generic timeekeping cleanups Compiled but otherwise untested. Cc: Paul Mackerras <paulus@samba.org> Cc: Anton Blanchard <anton@samba.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <johnstul@us.ibm.com> --- arch/powerpc/kernel/time.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 6fcd648..0711d60 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -864,9 +864,9 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, /* XXX this assumes clock->shift == 22 */ /* 4611686018 ~= 2^(20+64-22) / 1e9 */ new_tb_to_xs = (u64) mult * 4611686018ULL; - new_stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC; + new_stamp_xsec = (u64) wall_time->tv_nsec * XSEC_PER_SEC; do_div(new_stamp_xsec, 1000000000); - new_stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC; + new_stamp_xsec += (u64) wall_time->tv_sec * XSEC_PER_SEC; /* * tb_update_count is used to allow the userspace gettimeofday code @@ -884,7 +884,7 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, vdso_data->tb_to_xs = new_tb_to_xs; vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; - vdso_data->stamp_xtime = xtime; + vdso_data->stamp_xtime = *wall_time; smp_wmb(); ++(vdso_data->tb_update_count); } @@ -1093,7 +1093,7 @@ void __init time_init(void) vdso_data->tb_orig_stamp = tb_last_jiffy; vdso_data->tb_update_count = 0; vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; - vdso_data->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC; + vdso_data->stamp_xsec = (u64) get_seconds() * XSEC_PER_SEC; vdso_data->tb_to_xs = tb_to_xs; write_sequnlock_irqrestore(&xtime_lock, flags); -- 1.6.0.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 06/11] Fix update_vsyscall to provide wall_to_monotonic offset 2010-07-14 0:56 ` [PATCH 05/11] powerpc: Cleanup xtime usage John Stultz @ 2010-07-14 0:56 ` John Stultz 2010-07-14 0:56 ` [PATCH 07/11] Convert um to use read_persistent_clock John Stultz 2010-07-27 10:47 ` [tip:timers/clocksource] timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset tip-bot for John Stultz 2010-07-27 10:47 ` [tip:timers/clocksource] powerpc: Cleanup xtime usage tip-bot for John Stultz 1 sibling, 2 replies; 35+ messages in thread From: John Stultz @ 2010-07-14 0:56 UTC (permalink / raw) To: LKML Cc: John Stultz, Martin Schwidefsky, Anton Blanchard, Paul Mackerras, Tony Luck, Thomas Gleixner update_vsyscall() did not provide the wall_to_monotoinc offset, so arch specific implementations tend to reference wall_to_monotonic directly. This limits future cleanups in the timekeeping core, so this patch fixes the update_vsyscall interface to provide wall_to_monotonic, allowing wall_to_monotonic to be made static as planned in Documentation/feature-removal-schedule.txt Signed-off-by: John Stultz <johnstul@us.ibm.com> CC: Martin Schwidefsky <schwidefsky@de.ibm.com> CC: Anton Blanchard <anton@samba.org> CC: Paul Mackerras <paulus@samba.org> CC: Tony Luck <tony.luck@intel.com> CC: Thomas Gleixner <tglx@linutronix.de> --- arch/ia64/kernel/time.c | 7 ++++--- arch/powerpc/kernel/time.c | 8 ++++---- arch/s390/kernel/time.c | 8 ++++---- arch/x86/kernel/vsyscall_64.c | 6 +++--- include/linux/clocksource.h | 6 ++++-- kernel/time/timekeeping.c | 9 ++++++--- 6 files changed, 25 insertions(+), 19 deletions(-) diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c index 653b3c4..ed6f22e 100644 --- a/arch/ia64/kernel/time.c +++ b/arch/ia64/kernel/time.c @@ -471,7 +471,8 @@ void update_vsyscall_tz(void) { } -void update_vsyscall(struct timespec *wall, struct clocksource *c, u32 mult) +void update_vsyscall(struct timespec *wall, struct timespec *wtm, + struct clocksource *c, u32 mult) { unsigned long flags; @@ -487,9 +488,9 @@ void update_vsyscall(struct timespec *wall, struct clocksource *c, u32 mult) /* copy kernel time structures */ fsyscall_gtod_data.wall_time.tv_sec = wall->tv_sec; fsyscall_gtod_data.wall_time.tv_nsec = wall->tv_nsec; - fsyscall_gtod_data.monotonic_time.tv_sec = wall_to_monotonic.tv_sec + fsyscall_gtod_data.monotonic_time.tv_sec = wtm->tv_sec + wall->tv_sec; - fsyscall_gtod_data.monotonic_time.tv_nsec = wall_to_monotonic.tv_nsec + fsyscall_gtod_data.monotonic_time.tv_nsec = wtm->tv_nsec + wall->tv_nsec; /* normalize */ diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 0711d60..e215f76 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -849,8 +849,8 @@ static cycle_t timebase_read(struct clocksource *cs) return (cycle_t)get_tb(); } -void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, - u32 mult) +void update_vsyscall(struct timespec *wall_time, struct timespec *wtm, + struct clocksource *clock, u32 mult) { u64 new_tb_to_xs, new_stamp_xsec; @@ -882,8 +882,8 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, vdso_data->tb_orig_stamp = clock->cycle_last; vdso_data->stamp_xsec = new_stamp_xsec; vdso_data->tb_to_xs = new_tb_to_xs; - vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; - vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; + vdso_data->wtom_clock_sec = wtm->tv_sec; + vdso_data->wtom_clock_nsec = wtm->tv_nsec; vdso_data->stamp_xtime = *wall_time; smp_wmb(); ++(vdso_data->tb_update_count); diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index a2163c9..aeb30c6 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -207,8 +207,8 @@ struct clocksource * __init clocksource_default_clock(void) return &clocksource_tod; } -void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, - u32 mult) +void update_vsyscall(struct timespec *wall_time, struct timespec *wtm, + struct clocksource *clock, u32 mult) { if (clock != &clocksource_tod) return; @@ -219,8 +219,8 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, vdso_data->xtime_tod_stamp = clock->cycle_last; vdso_data->xtime_clock_sec = wall_time->tv_sec; vdso_data->xtime_clock_nsec = wall_time->tv_nsec; - vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; - vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; + vdso_data->wtom_clock_sec = wtm->tv_sec; + vdso_data->wtom_clock_nsec = wtm->tv_nsec; vdso_data->ntp_mult = mult; smp_wmb(); ++vdso_data->tb_update_count; diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index dce0c3c..dcbb28c 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -73,8 +73,8 @@ void update_vsyscall_tz(void) write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags); } -void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, - u32 mult) +void update_vsyscall(struct timespec *wall_time, struct timespec *wtm, + struct clocksource *clock, u32 mult) { unsigned long flags; @@ -87,7 +87,7 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, vsyscall_gtod_data.clock.shift = clock->shift; vsyscall_gtod_data.wall_time_sec = wall_time->tv_sec; vsyscall_gtod_data.wall_time_nsec = wall_time->tv_nsec; - vsyscall_gtod_data.wall_to_monotonic = wall_to_monotonic; + vsyscall_gtod_data.wall_to_monotonic = *wtm; vsyscall_gtod_data.wall_time_coarse = __current_kernel_time(); write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags); } diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 5ea3c60..21677d9 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -313,11 +313,13 @@ clocksource_calc_mult_shift(struct clocksource *cs, u32 freq, u32 minsec) #ifdef CONFIG_GENERIC_TIME_VSYSCALL extern void -update_vsyscall(struct timespec *ts, struct clocksource *c, u32 mult); +update_vsyscall(struct timespec *ts, struct timespec *wtm, + struct clocksource *c, u32 mult); extern void update_vsyscall_tz(void); #else static inline void -update_vsyscall(struct timespec *ts, struct clocksource *c, u32 mult) +update_vsyscall(struct timespec *ts, struct timespec *wtm, + struct clocksource *c, u32 mult) { } diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 73edd40..b15c3ac 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -170,7 +170,8 @@ void timekeeping_leap_insert(int leapsecond) { xtime.tv_sec += leapsecond; wall_to_monotonic.tv_sec -= leapsecond; - update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult); + update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, + timekeeper.mult); } /** @@ -326,7 +327,8 @@ int do_settimeofday(struct timespec *tv) timekeeper.ntp_error = 0; ntp_clear(); - update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult); + update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, + timekeeper.mult); write_sequnlock_irqrestore(&xtime_lock, flags); @@ -809,7 +811,8 @@ void update_wall_time(void) } /* check to see if there is a new clocksource to use */ - update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult); + update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, + timekeeper.mult); } /** -- 1.6.0.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 07/11] Convert um to use read_persistent_clock 2010-07-14 0:56 ` [PATCH 06/11] Fix update_vsyscall to provide wall_to_monotonic offset John Stultz @ 2010-07-14 0:56 ` John Stultz 2010-07-14 0:56 ` [PATCH 08/11] Cleanup hrtimer.c's direct access to wall_to_monotonic John Stultz 2010-07-27 10:47 ` [tip:timers/clocksource] um: Convert to use read_persistent_clock tip-bot for John Stultz 2010-07-27 10:47 ` [tip:timers/clocksource] timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset tip-bot for John Stultz 1 sibling, 2 replies; 35+ messages in thread From: John Stultz @ 2010-07-14 0:56 UTC (permalink / raw) To: LKML; +Cc: John Stultz, Jeff Dike, Thomas Gleixner This patch converts the um arch to use read_persistent_clock(). This allows it to avoid accessing xtime and wall_to_monotonic directly. This patch is un-tested, so any help by testers or maintainers would be greatly appreciated! Signed-off-by: John Stultz <johnstul@us.ibm.com> CC: Jeff Dike <jdike@addtoit.com> CC: Thomas Gleixner <tglx@linutronix.de> --- arch/um/kernel/time.c | 13 +++++++------ 1 files changed, 7 insertions(+), 6 deletions(-) diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c index c8b9c46..2b8b262 100644 --- a/arch/um/kernel/time.c +++ b/arch/um/kernel/time.c @@ -102,16 +102,17 @@ static void __init setup_itimer(void) clockevents_register_device(&itimer_clockevent); } +void read_persistent_clock(struct timespec *ts) +{ + nsecs = os_nsecs(); + set_normalized_timespec(ts, nsecs / NSEC_PER_SEC, + nsecs % NSEC_PER_SEC); +} + void __init time_init(void) { long long nsecs; timer_init(); - - nsecs = os_nsecs(); - set_normalized_timespec(&wall_to_monotonic, -nsecs / NSEC_PER_SEC, - -nsecs % NSEC_PER_SEC); - set_normalized_timespec(&xtime, nsecs / NSEC_PER_SEC, - nsecs % NSEC_PER_SEC); late_time_init = setup_itimer; } -- 1.6.0.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 08/11] Cleanup hrtimer.c's direct access to wall_to_monotonic 2010-07-14 0:56 ` [PATCH 07/11] Convert um to use read_persistent_clock John Stultz @ 2010-07-14 0:56 ` John Stultz 2010-07-14 0:56 ` [PATCH 09/11] Make xtime and wall_to_monotonic static John Stultz 2010-07-27 10:48 ` [tip:timers/clocksource] hrtimer: Cleanup direct access to wall_to_monotonic tip-bot for John Stultz 2010-07-27 10:47 ` [tip:timers/clocksource] um: Convert to use read_persistent_clock tip-bot for John Stultz 1 sibling, 2 replies; 35+ messages in thread From: John Stultz @ 2010-07-14 0:56 UTC (permalink / raw) To: LKML; +Cc: John Stultz, Thomas Gleixner Provides an accessor function to replace hrtimer.c's direct access of wall_to_monotonic. This will allow wall_to_monotonic to be made static as planned in Documentation/feature-removal-schedule.txt Signed-off-by: John Stultz <johnstul@us.ibm.com> CC: Thomas Gleixner <tglx@linutronix.de> --- include/linux/time.h | 3 ++- kernel/hrtimer.c | 9 ++++----- kernel/time/timekeeping.c | 5 +++++ 3 files changed, 11 insertions(+), 6 deletions(-) diff --git a/include/linux/time.h b/include/linux/time.h index 36b42f5..3a9c0bf 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -126,7 +126,8 @@ extern int timekeeping_suspended; unsigned long get_seconds(void); struct timespec current_kernel_time(void); -struct timespec __current_kernel_time(void); /* does not hold xtime_lock */ +struct timespec __current_kernel_time(void); /* does not take xtime_lock */ +struct timespec __get_wall_to_monotonic(void); /* does not take xtime_lock */ struct timespec get_monotonic_coarse(void); #define CURRENT_TIME (current_kernel_time()) diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 5c69e99..809f48c 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -90,7 +90,7 @@ static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) do { seq = read_seqbegin(&xtime_lock); xts = __current_kernel_time(); - tom = wall_to_monotonic; + tom = __get_wall_to_monotonic(); } while (read_seqretry(&xtime_lock, seq)); xtim = timespec_to_ktime(xts); @@ -612,7 +612,7 @@ static int hrtimer_reprogram(struct hrtimer *timer, static void retrigger_next_event(void *arg) { struct hrtimer_cpu_base *base; - struct timespec realtime_offset; + struct timespec realtime_offset, wtm; unsigned long seq; if (!hrtimer_hres_active()) @@ -620,10 +620,9 @@ static void retrigger_next_event(void *arg) do { seq = read_seqbegin(&xtime_lock); - set_normalized_timespec(&realtime_offset, - -wall_to_monotonic.tv_sec, - -wall_to_monotonic.tv_nsec); + wtm = __get_wall_to_monotonic(); } while (read_seqretry(&xtime_lock, seq)); + set_normalized_timespec(&realtime_offset, -wtm.tv_sec, -wtm.tv_nsec); base = &__get_cpu_var(hrtimer_bases); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index b15c3ac..fb61c2e 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -858,6 +858,11 @@ struct timespec __current_kernel_time(void) return xtime; } +struct timespec __get_wall_to_monotonic(void) +{ + return wall_to_monotonic; +} + struct timespec current_kernel_time(void) { struct timespec now; -- 1.6.0.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 09/11] Make xtime and wall_to_monotonic static 2010-07-14 0:56 ` [PATCH 08/11] Cleanup hrtimer.c's direct access to wall_to_monotonic John Stultz @ 2010-07-14 0:56 ` John Stultz 2010-07-14 0:56 ` [PATCH 10/11] Convert common x86 clocksources to use clocksource_register_hz/khz John Stultz 2010-07-27 10:48 ` [tip:timers/clocksource] timekeeping: Make xtime and wall_to_monotonic static tip-bot for John Stultz 2010-07-27 10:48 ` [tip:timers/clocksource] hrtimer: Cleanup direct access to wall_to_monotonic tip-bot for John Stultz 1 sibling, 2 replies; 35+ messages in thread From: John Stultz @ 2010-07-14 0:56 UTC (permalink / raw) To: LKML; +Cc: John Stultz, Thomas Gleixner This patch makes xtime and wall_to_monotonic static, as planned in Documentation/feature-removal-schedule.txt. This will allow for further cleanups to the timekeeping core. Signed-off-by: John Stultz <johnstul@us.ibm.com> CC: Thomas Gleixner <tglx@linutronix.de> --- Documentation/feature-removal-schedule.txt | 10 ---------- include/linux/time.h | 2 -- kernel/time/timekeeping.c | 4 ++-- 3 files changed, 2 insertions(+), 14 deletions(-) diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index c268783..0d91c6b 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -549,16 +549,6 @@ Who: Avi Kivity <avi@redhat.com> ---------------------------- -What: xtime, wall_to_monotonic -When: 2.6.36+ -Files: kernel/time/timekeeping.c include/linux/time.h -Why: Cleaning up timekeeping internal values. Please use - existing timekeeping accessor functions to access - the equivalent functionality. -Who: John Stultz <johnstul@us.ibm.com> - ----------------------------- - What: KVM kernel-allocated memory slots When: July 2010 Why: Since 2.6.25, kvm supports user-allocated memory slots, which are diff --git a/include/linux/time.h b/include/linux/time.h index 3a9c0bf..50b3cb0 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -113,8 +113,6 @@ static inline struct timespec timespec_sub(struct timespec lhs, #define timespec_valid(ts) \ (((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC)) -extern struct timespec xtime; -extern struct timespec wall_to_monotonic; extern seqlock_t xtime_lock; extern void read_persistent_clock(struct timespec *ts); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index fb61c2e..e14c839 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -153,8 +153,8 @@ __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); * - wall_to_monotonic is no longer the boot time, getboottime must be * used instead. */ -struct timespec xtime __attribute__ ((aligned (16))); -struct timespec wall_to_monotonic __attribute__ ((aligned (16))); +static struct timespec xtime __attribute__ ((aligned (16))); +static struct timespec wall_to_monotonic __attribute__ ((aligned (16))); static struct timespec total_sleep_time; /* -- 1.6.0.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 10/11] Convert common x86 clocksources to use clocksource_register_hz/khz 2010-07-14 0:56 ` [PATCH 09/11] Make xtime and wall_to_monotonic static John Stultz @ 2010-07-14 0:56 ` John Stultz 2010-07-14 0:56 ` [PATCH 11/11] Add __clocksource_updatefreq_hz/khz methods John Stultz 2010-07-27 10:48 ` [tip:timers/clocksource] x86: Convert common clocksources to use clocksource_register_hz/khz tip-bot for John Stultz 2010-07-27 10:48 ` [tip:timers/clocksource] timekeeping: Make xtime and wall_to_monotonic static tip-bot for John Stultz 1 sibling, 2 replies; 35+ messages in thread From: John Stultz @ 2010-07-14 0:56 UTC (permalink / raw) To: LKML; +Cc: John Stultz, Thomas Gleixner This converts the most common of the x86 clocksources over to use clocksource_register_hz/khz. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <johnstul@us.ibm.com> --- arch/x86/kernel/hpet.c | 13 +++++++++---- arch/x86/kernel/tsc.c | 6 ++---- drivers/clocksource/acpi_pm.c | 9 ++------- 3 files changed, 13 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index a198b7c..54dac04 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -16,7 +16,6 @@ #include <asm/hpet.h> #define HPET_MASK CLOCKSOURCE_MASK(32) -#define HPET_SHIFT 22 /* FSEC = 10^-15 NSEC = 10^-9 */ @@ -787,7 +786,6 @@ static struct clocksource clocksource_hpet = { .rating = 250, .read = read_hpet, .mask = HPET_MASK, - .shift = HPET_SHIFT, .flags = CLOCK_SOURCE_IS_CONTINUOUS, .resume = hpet_resume_counter, #ifdef CONFIG_X86_64 @@ -798,6 +796,7 @@ static struct clocksource clocksource_hpet = { static int hpet_clocksource_register(void) { u64 start, now; + u64 hpet_freq; cycle_t t1; /* Start the counter */ @@ -832,9 +831,15 @@ static int hpet_clocksource_register(void) * mult = (hpet_period * 2^shift)/10^6 * mult = (hpet_period << shift)/FSEC_PER_NSEC */ - clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT); - clocksource_register(&clocksource_hpet); + /* Need to convert hpet_period (fsec/cyc) to cyc/sec: + * + * cyc/sec = FSEC_PER_SEC/hpet_period(fsec/cyc) + * cyc/sec = (FSEC_PER_NSEC * NSEC_PER_SEC)/hpet_period + */ + hpet_freq = FSEC_PER_NSEC * NSEC_PER_SEC; + do_div(hpet_freq, hpet_period); + clocksource_register_hz(&clocksource_hpet, (u32)hpet_freq); return 0; } diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 9faf91a..5ca6370 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -751,7 +751,6 @@ static struct clocksource clocksource_tsc = { .read = read_tsc, .resume = resume_tsc, .mask = CLOCKSOURCE_MASK(64), - .shift = 22, .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_MUST_VERIFY, #ifdef CONFIG_X86_64 @@ -845,8 +844,6 @@ __cpuinit int unsynchronized_tsc(void) static void __init init_tsc_clocksource(void) { - clocksource_tsc.mult = clocksource_khz2mult(tsc_khz, - clocksource_tsc.shift); if (tsc_clocksource_reliable) clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY; /* lower the rating if we already know its unstable: */ @@ -854,7 +851,8 @@ static void __init init_tsc_clocksource(void) clocksource_tsc.rating = 0; clocksource_tsc.flags &= ~CLOCK_SOURCE_IS_CONTINUOUS; } - clocksource_register(&clocksource_tsc); + + clocksource_register_khz(&clocksource_tsc, tsc_khz); } #ifdef CONFIG_X86_64 diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c index 72a633a..cfb0f52 100644 --- a/drivers/clocksource/acpi_pm.c +++ b/drivers/clocksource/acpi_pm.c @@ -68,10 +68,7 @@ static struct clocksource clocksource_acpi_pm = { .rating = 200, .read = acpi_pm_read, .mask = (cycle_t)ACPI_PM_MASK, - .mult = 0, /*to be calculated*/ - .shift = 22, .flags = CLOCK_SOURCE_IS_CONTINUOUS, - }; @@ -190,9 +187,6 @@ static int __init init_acpi_pm_clocksource(void) if (!pmtmr_ioport) return -ENODEV; - clocksource_acpi_pm.mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, - clocksource_acpi_pm.shift); - /* "verify" this timing source: */ for (j = 0; j < ACPI_PM_MONOTONICITY_CHECKS; j++) { udelay(100 * j); @@ -220,7 +214,8 @@ static int __init init_acpi_pm_clocksource(void) if (verify_pmtmr_rate() != 0) return -ENODEV; - return clocksource_register(&clocksource_acpi_pm); + return clocksource_register_hz(&clocksource_acpi_pm, + PMTMR_TICKS_PER_SEC); } /* We use fs_initcall because we want the PCI fixups to have run -- 1.6.0.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [PATCH 11/11] Add __clocksource_updatefreq_hz/khz methods 2010-07-14 0:56 ` [PATCH 10/11] Convert common x86 clocksources to use clocksource_register_hz/khz John Stultz @ 2010-07-14 0:56 ` John Stultz 2010-07-27 10:49 ` [tip:timers/clocksource] clocksource: " tip-bot for John Stultz 2010-07-27 10:48 ` [tip:timers/clocksource] x86: Convert common clocksources to use clocksource_register_hz/khz tip-bot for John Stultz 1 sibling, 1 reply; 35+ messages in thread From: John Stultz @ 2010-07-14 0:56 UTC (permalink / raw) To: LKML; +Cc: John Stultz, Thomas Gleixner To properly handle clocksources that change frequencies at the clocksource->enable() point, this patch adds a method that will update the clocksource's mult/shift and max_idle_ns values. Signed-off-by: John Stultz <johnstul@us.ibm.com> CC: Thomas Gleixner <tglx@linutronix.de> --- include/linux/clocksource.h | 11 +++++++++++ kernel/time/clocksource.c | 29 ++++++++++++++++++++++++----- 2 files changed, 35 insertions(+), 5 deletions(-) diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 21677d9..edd20e6 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -292,6 +292,8 @@ clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec); */ extern int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq); +extern void +__clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq); static inline int clocksource_register_hz(struct clocksource *cs, u32 hz) { @@ -303,6 +305,15 @@ static inline int clocksource_register_khz(struct clocksource *cs, u32 khz) return __clocksource_register_scale(cs, 1000, khz); } +static inline void __clocksource_updatefreq_hz(struct clocksource *cs, u32 hz) +{ + __clocksource_updatefreq_scale(cs, 1, hz); +} + +static inline void __clocksource_updatefreq_khz(struct clocksource *cs, u32 khz) +{ + __clocksource_updatefreq_scale(cs, 1000, khz); +} static inline void clocksource_calc_mult_shift(struct clocksource *cs, u32 freq, u32 minsec) diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index c543d21..c18d7ef 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -639,19 +639,18 @@ static void clocksource_enqueue(struct clocksource *cs) #define MAX_UPDATE_LENGTH 5 /* Seconds */ /** - * __clocksource_register_scale - Used to install new clocksources + * __clocksource_updatefreq_scale - Used update clocksource with new freq * @t: clocksource to be registered * @scale: Scale factor multiplied against freq to get clocksource hz * @freq: clocksource frequency (cycles per second) divided by scale * - * Returns -EBUSY if registration fails, zero otherwise. + * This should only be called from the clocksource->enable() method. * * This *SHOULD NOT* be called directly! Please use the - * clocksource_register_hz() or clocksource_register_khz helper functions. + * clocksource_updatefreq_hz() or clocksource_updatefreq_khz helper functions. */ -int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq) +void __clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq) { - /* * Ideally we want to use some of the limits used in * clocksource_max_deferment, to provide a more informed @@ -662,7 +661,27 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq) NSEC_PER_SEC/scale, MAX_UPDATE_LENGTH*scale); cs->max_idle_ns = clocksource_max_deferment(cs); +} +EXPORT_SYMBOL_GPL(__clocksource_updatefreq_scale); + +/** + * __clocksource_register_scale - Used to install new clocksources + * @t: clocksource to be registered + * @scale: Scale factor multiplied against freq to get clocksource hz + * @freq: clocksource frequency (cycles per second) divided by scale + * + * Returns -EBUSY if registration fails, zero otherwise. + * + * This *SHOULD NOT* be called directly! Please use the + * clocksource_register_hz() or clocksource_register_khz helper functions. + */ +int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq) +{ + + /* Intialize mult/shift and max_idle_ns */ + __clocksource_updatefreq_scale(cs, scale, freq); + /* Add clocksource to the clcoksource list */ mutex_lock(&clocksource_mutex); clocksource_enqueue(cs); clocksource_select(); -- 1.6.0.4 ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [tip:timers/clocksource] clocksource: Add __clocksource_updatefreq_hz/khz methods 2010-07-14 0:56 ` [PATCH 11/11] Add __clocksource_updatefreq_hz/khz methods John Stultz @ 2010-07-27 10:49 ` tip-bot for John Stultz 0 siblings, 0 replies; 35+ messages in thread From: tip-bot for John Stultz @ 2010-07-27 10:49 UTC (permalink / raw) To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, johnstul, tglx Commit-ID: 852db46d55e85b475a72e665ca08d3317769ceef Gitweb: http://git.kernel.org/tip/852db46d55e85b475a72e665ca08d3317769ceef Author: John Stultz <johnstul@us.ibm.com> AuthorDate: Tue, 13 Jul 2010 17:56:28 -0700 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Tue, 27 Jul 2010 12:40:55 +0200 clocksource: Add __clocksource_updatefreq_hz/khz methods To properly handle clocksources that change frequencies at the clocksource->enable() point, this patch adds a method that will update the clocksource's mult/shift and max_idle_ns values. Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1279068988-21864-12-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- include/linux/clocksource.h | 11 +++++++++++ kernel/time/clocksource.c | 29 ++++++++++++++++++++++++----- 2 files changed, 35 insertions(+), 5 deletions(-) diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 21677d9..c37b21a 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -292,6 +292,8 @@ clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec); */ extern int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq); +extern void +__clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq); static inline int clocksource_register_hz(struct clocksource *cs, u32 hz) { @@ -303,6 +305,15 @@ static inline int clocksource_register_khz(struct clocksource *cs, u32 khz) return __clocksource_register_scale(cs, 1000, khz); } +static inline void __clocksource_updatefreq_hz(struct clocksource *cs, u32 hz) +{ + __clocksource_updatefreq_scale(cs, 1, hz); +} + +static inline void __clocksource_updatefreq_khz(struct clocksource *cs, u32 khz) +{ + __clocksource_updatefreq_scale(cs, 1000, khz); +} static inline void clocksource_calc_mult_shift(struct clocksource *cs, u32 freq, u32 minsec) diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index c543d21..c18d7ef 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -639,19 +639,18 @@ static void clocksource_enqueue(struct clocksource *cs) #define MAX_UPDATE_LENGTH 5 /* Seconds */ /** - * __clocksource_register_scale - Used to install new clocksources + * __clocksource_updatefreq_scale - Used update clocksource with new freq * @t: clocksource to be registered * @scale: Scale factor multiplied against freq to get clocksource hz * @freq: clocksource frequency (cycles per second) divided by scale * - * Returns -EBUSY if registration fails, zero otherwise. + * This should only be called from the clocksource->enable() method. * * This *SHOULD NOT* be called directly! Please use the - * clocksource_register_hz() or clocksource_register_khz helper functions. + * clocksource_updatefreq_hz() or clocksource_updatefreq_khz helper functions. */ -int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq) +void __clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq) { - /* * Ideally we want to use some of the limits used in * clocksource_max_deferment, to provide a more informed @@ -662,7 +661,27 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq) NSEC_PER_SEC/scale, MAX_UPDATE_LENGTH*scale); cs->max_idle_ns = clocksource_max_deferment(cs); +} +EXPORT_SYMBOL_GPL(__clocksource_updatefreq_scale); + +/** + * __clocksource_register_scale - Used to install new clocksources + * @t: clocksource to be registered + * @scale: Scale factor multiplied against freq to get clocksource hz + * @freq: clocksource frequency (cycles per second) divided by scale + * + * Returns -EBUSY if registration fails, zero otherwise. + * + * This *SHOULD NOT* be called directly! Please use the + * clocksource_register_hz() or clocksource_register_khz helper functions. + */ +int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq) +{ + + /* Intialize mult/shift and max_idle_ns */ + __clocksource_updatefreq_scale(cs, scale, freq); + /* Add clocksource to the clcoksource list */ mutex_lock(&clocksource_mutex); clocksource_enqueue(cs); clocksource_select(); ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [tip:timers/clocksource] x86: Convert common clocksources to use clocksource_register_hz/khz 2010-07-14 0:56 ` [PATCH 10/11] Convert common x86 clocksources to use clocksource_register_hz/khz John Stultz 2010-07-14 0:56 ` [PATCH 11/11] Add __clocksource_updatefreq_hz/khz methods John Stultz @ 2010-07-27 10:48 ` tip-bot for John Stultz 1 sibling, 0 replies; 35+ messages in thread From: tip-bot for John Stultz @ 2010-07-27 10:48 UTC (permalink / raw) To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, johnstul, tglx Commit-ID: f12a15be63d1de9a35971f35f06b73088fa25c3a Gitweb: http://git.kernel.org/tip/f12a15be63d1de9a35971f35f06b73088fa25c3a Author: John Stultz <johnstul@us.ibm.com> AuthorDate: Tue, 13 Jul 2010 17:56:27 -0700 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Tue, 27 Jul 2010 12:40:55 +0200 x86: Convert common clocksources to use clocksource_register_hz/khz This converts the most common of the x86 clocksources over to use clocksource_register_hz/khz. Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1279068988-21864-11-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- arch/x86/kernel/hpet.c | 13 +++++++++---- arch/x86/kernel/tsc.c | 5 +---- drivers/clocksource/acpi_pm.c | 9 ++------- 3 files changed, 12 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index ba390d7..33dbcc4 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -16,7 +16,6 @@ #include <asm/hpet.h> #define HPET_MASK CLOCKSOURCE_MASK(32) -#define HPET_SHIFT 22 /* FSEC = 10^-15 NSEC = 10^-9 */ @@ -787,7 +786,6 @@ static struct clocksource clocksource_hpet = { .rating = 250, .read = read_hpet, .mask = HPET_MASK, - .shift = HPET_SHIFT, .flags = CLOCK_SOURCE_IS_CONTINUOUS, .resume = hpet_resume_counter, #ifdef CONFIG_X86_64 @@ -798,6 +796,7 @@ static struct clocksource clocksource_hpet = { static int hpet_clocksource_register(void) { u64 start, now; + u64 hpet_freq; cycle_t t1; /* Start the counter */ @@ -832,9 +831,15 @@ static int hpet_clocksource_register(void) * mult = (hpet_period * 2^shift)/10^6 * mult = (hpet_period << shift)/FSEC_PER_NSEC */ - clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT); - clocksource_register(&clocksource_hpet); + /* Need to convert hpet_period (fsec/cyc) to cyc/sec: + * + * cyc/sec = FSEC_PER_SEC/hpet_period(fsec/cyc) + * cyc/sec = (FSEC_PER_NSEC * NSEC_PER_SEC)/hpet_period + */ + hpet_freq = FSEC_PER_NSEC * NSEC_PER_SEC; + do_div(hpet_freq, hpet_period); + clocksource_register_hz(&clocksource_hpet, (u32)hpet_freq); return 0; } diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 9faf91a..ce8e502 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -751,7 +751,6 @@ static struct clocksource clocksource_tsc = { .read = read_tsc, .resume = resume_tsc, .mask = CLOCKSOURCE_MASK(64), - .shift = 22, .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_MUST_VERIFY, #ifdef CONFIG_X86_64 @@ -845,8 +844,6 @@ __cpuinit int unsynchronized_tsc(void) static void __init init_tsc_clocksource(void) { - clocksource_tsc.mult = clocksource_khz2mult(tsc_khz, - clocksource_tsc.shift); if (tsc_clocksource_reliable) clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY; /* lower the rating if we already know its unstable: */ @@ -854,7 +851,7 @@ static void __init init_tsc_clocksource(void) clocksource_tsc.rating = 0; clocksource_tsc.flags &= ~CLOCK_SOURCE_IS_CONTINUOUS; } - clocksource_register(&clocksource_tsc); + clocksource_register_khz(&clocksource_tsc, tsc_khz); } #ifdef CONFIG_X86_64 diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c index 72a633a..cfb0f52 100644 --- a/drivers/clocksource/acpi_pm.c +++ b/drivers/clocksource/acpi_pm.c @@ -68,10 +68,7 @@ static struct clocksource clocksource_acpi_pm = { .rating = 200, .read = acpi_pm_read, .mask = (cycle_t)ACPI_PM_MASK, - .mult = 0, /*to be calculated*/ - .shift = 22, .flags = CLOCK_SOURCE_IS_CONTINUOUS, - }; @@ -190,9 +187,6 @@ static int __init init_acpi_pm_clocksource(void) if (!pmtmr_ioport) return -ENODEV; - clocksource_acpi_pm.mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, - clocksource_acpi_pm.shift); - /* "verify" this timing source: */ for (j = 0; j < ACPI_PM_MONOTONICITY_CHECKS; j++) { udelay(100 * j); @@ -220,7 +214,8 @@ static int __init init_acpi_pm_clocksource(void) if (verify_pmtmr_rate() != 0) return -ENODEV; - return clocksource_register(&clocksource_acpi_pm); + return clocksource_register_hz(&clocksource_acpi_pm, + PMTMR_TICKS_PER_SEC); } /* We use fs_initcall because we want the PCI fixups to have run ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [tip:timers/clocksource] timekeeping: Make xtime and wall_to_monotonic static 2010-07-14 0:56 ` [PATCH 09/11] Make xtime and wall_to_monotonic static John Stultz 2010-07-14 0:56 ` [PATCH 10/11] Convert common x86 clocksources to use clocksource_register_hz/khz John Stultz @ 2010-07-27 10:48 ` tip-bot for John Stultz 1 sibling, 0 replies; 35+ messages in thread From: tip-bot for John Stultz @ 2010-07-27 10:48 UTC (permalink / raw) To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, johnstul, tglx Commit-ID: 0fb86b06298b6cd3205cac2e68a499f269282dac Gitweb: http://git.kernel.org/tip/0fb86b06298b6cd3205cac2e68a499f269282dac Author: John Stultz <johnstul@us.ibm.com> AuthorDate: Tue, 13 Jul 2010 17:56:26 -0700 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Tue, 27 Jul 2010 12:40:55 +0200 timekeeping: Make xtime and wall_to_monotonic static This patch makes xtime and wall_to_monotonic static, as planned in Documentation/feature-removal-schedule.txt. This will allow for further cleanups to the timekeeping core. Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1279068988-21864-10-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- Documentation/feature-removal-schedule.txt | 10 ---------- include/linux/time.h | 2 -- kernel/time/timekeeping.c | 4 ++-- 3 files changed, 2 insertions(+), 14 deletions(-) diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 1571c0c..cd648db 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -549,16 +549,6 @@ Who: Avi Kivity <avi@redhat.com> ---------------------------- -What: xtime, wall_to_monotonic -When: 2.6.36+ -Files: kernel/time/timekeeping.c include/linux/time.h -Why: Cleaning up timekeeping internal values. Please use - existing timekeeping accessor functions to access - the equivalent functionality. -Who: John Stultz <johnstul@us.ibm.com> - ----------------------------- - What: KVM kernel-allocated memory slots When: July 2010 Why: Since 2.6.25, kvm supports user-allocated memory slots, which are diff --git a/include/linux/time.h b/include/linux/time.h index a57e0f6..cb34e35 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -113,8 +113,6 @@ static inline struct timespec timespec_sub(struct timespec lhs, #define timespec_valid(ts) \ (((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC)) -extern struct timespec xtime; -extern struct timespec wall_to_monotonic; extern seqlock_t xtime_lock; extern void read_persistent_clock(struct timespec *ts); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index fb61c2e..e14c839 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -153,8 +153,8 @@ __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); * - wall_to_monotonic is no longer the boot time, getboottime must be * used instead. */ -struct timespec xtime __attribute__ ((aligned (16))); -struct timespec wall_to_monotonic __attribute__ ((aligned (16))); +static struct timespec xtime __attribute__ ((aligned (16))); +static struct timespec wall_to_monotonic __attribute__ ((aligned (16))); static struct timespec total_sleep_time; /* ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [tip:timers/clocksource] hrtimer: Cleanup direct access to wall_to_monotonic 2010-07-14 0:56 ` [PATCH 08/11] Cleanup hrtimer.c's direct access to wall_to_monotonic John Stultz 2010-07-14 0:56 ` [PATCH 09/11] Make xtime and wall_to_monotonic static John Stultz @ 2010-07-27 10:48 ` tip-bot for John Stultz 1 sibling, 0 replies; 35+ messages in thread From: tip-bot for John Stultz @ 2010-07-27 10:48 UTC (permalink / raw) To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, johnstul, tglx Commit-ID: 8ab4351a4c888016620f43bde605b3d0964af339 Gitweb: http://git.kernel.org/tip/8ab4351a4c888016620f43bde605b3d0964af339 Author: John Stultz <johnstul@us.ibm.com> AuthorDate: Tue, 13 Jul 2010 17:56:25 -0700 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Tue, 27 Jul 2010 12:40:55 +0200 hrtimer: Cleanup direct access to wall_to_monotonic Provides an accessor function to replace hrtimer.c's direct access of wall_to_monotonic. This will allow wall_to_monotonic to be made static as planned in Documentation/feature-removal-schedule.txt Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1279068988-21864-9-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- include/linux/time.h | 3 ++- kernel/hrtimer.c | 9 ++++----- kernel/time/timekeeping.c | 5 +++++ 3 files changed, 11 insertions(+), 6 deletions(-) diff --git a/include/linux/time.h b/include/linux/time.h index 9072df8..a57e0f6 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -126,7 +126,8 @@ extern int timekeeping_suspended; unsigned long get_seconds(void); struct timespec current_kernel_time(void); -struct timespec __current_kernel_time(void); /* does not hold xtime_lock */ +struct timespec __current_kernel_time(void); /* does not take xtime_lock */ +struct timespec __get_wall_to_monotonic(void); /* does not take xtime_lock */ struct timespec get_monotonic_coarse(void); #define CURRENT_TIME (current_kernel_time()) diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 5c69e99..809f48c 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -90,7 +90,7 @@ static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) do { seq = read_seqbegin(&xtime_lock); xts = __current_kernel_time(); - tom = wall_to_monotonic; + tom = __get_wall_to_monotonic(); } while (read_seqretry(&xtime_lock, seq)); xtim = timespec_to_ktime(xts); @@ -612,7 +612,7 @@ static int hrtimer_reprogram(struct hrtimer *timer, static void retrigger_next_event(void *arg) { struct hrtimer_cpu_base *base; - struct timespec realtime_offset; + struct timespec realtime_offset, wtm; unsigned long seq; if (!hrtimer_hres_active()) @@ -620,10 +620,9 @@ static void retrigger_next_event(void *arg) do { seq = read_seqbegin(&xtime_lock); - set_normalized_timespec(&realtime_offset, - -wall_to_monotonic.tv_sec, - -wall_to_monotonic.tv_nsec); + wtm = __get_wall_to_monotonic(); } while (read_seqretry(&xtime_lock, seq)); + set_normalized_timespec(&realtime_offset, -wtm.tv_sec, -wtm.tv_nsec); base = &__get_cpu_var(hrtimer_bases); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index b15c3ac..fb61c2e 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -858,6 +858,11 @@ struct timespec __current_kernel_time(void) return xtime; } +struct timespec __get_wall_to_monotonic(void) +{ + return wall_to_monotonic; +} + struct timespec current_kernel_time(void) { struct timespec now; ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [tip:timers/clocksource] um: Convert to use read_persistent_clock 2010-07-14 0:56 ` [PATCH 07/11] Convert um to use read_persistent_clock John Stultz 2010-07-14 0:56 ` [PATCH 08/11] Cleanup hrtimer.c's direct access to wall_to_monotonic John Stultz @ 2010-07-27 10:47 ` tip-bot for John Stultz 1 sibling, 0 replies; 35+ messages in thread From: tip-bot for John Stultz @ 2010-07-27 10:47 UTC (permalink / raw) To: linux-tip-commits; +Cc: linux-kernel, jdike, hpa, mingo, johnstul, tglx Commit-ID: 9f31f5774961a735687fee17953ab505b3df3abf Gitweb: http://git.kernel.org/tip/9f31f5774961a735687fee17953ab505b3df3abf Author: John Stultz <johnstul@us.ibm.com> AuthorDate: Tue, 13 Jul 2010 17:56:24 -0700 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Tue, 27 Jul 2010 12:40:55 +0200 um: Convert to use read_persistent_clock This patch converts the um arch to use read_persistent_clock(). This allows it to avoid accessing xtime and wall_to_monotonic directly. Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Jeff Dike <jdike@addtoit.com> LKML-Reference: <1279068988-21864-8-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- arch/um/kernel/time.c | 13 +++++++------ 1 files changed, 7 insertions(+), 6 deletions(-) diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c index c8b9c46..2b8b262 100644 --- a/arch/um/kernel/time.c +++ b/arch/um/kernel/time.c @@ -102,16 +102,17 @@ static void __init setup_itimer(void) clockevents_register_device(&itimer_clockevent); } +void read_persistent_clock(struct timespec *ts) +{ + nsecs = os_nsecs(); + set_normalized_timespec(ts, nsecs / NSEC_PER_SEC, + nsecs % NSEC_PER_SEC); +} + void __init time_init(void) { long long nsecs; timer_init(); - - nsecs = os_nsecs(); - set_normalized_timespec(&wall_to_monotonic, -nsecs / NSEC_PER_SEC, - -nsecs % NSEC_PER_SEC); - set_normalized_timespec(&xtime, nsecs / NSEC_PER_SEC, - nsecs % NSEC_PER_SEC); late_time_init = setup_itimer; } ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [tip:timers/clocksource] timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset 2010-07-14 0:56 ` [PATCH 06/11] Fix update_vsyscall to provide wall_to_monotonic offset John Stultz 2010-07-14 0:56 ` [PATCH 07/11] Convert um to use read_persistent_clock John Stultz @ 2010-07-27 10:47 ` tip-bot for John Stultz 1 sibling, 0 replies; 35+ messages in thread From: tip-bot for John Stultz @ 2010-07-27 10:47 UTC (permalink / raw) To: linux-tip-commits Cc: linux-kernel, paulus, anton, hpa, mingo, johnstul, schwidefsky, tony.luck, tglx Commit-ID: 7615856ebfee52b080c22d263ca4debbd0df0ac1 Gitweb: http://git.kernel.org/tip/7615856ebfee52b080c22d263ca4debbd0df0ac1 Author: John Stultz <johnstul@us.ibm.com> AuthorDate: Tue, 13 Jul 2010 17:56:23 -0700 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Tue, 27 Jul 2010 12:40:54 +0200 timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset update_vsyscall() did not provide the wall_to_monotoinc offset, so arch specific implementations tend to reference wall_to_monotonic directly. This limits future cleanups in the timekeeping core, so this patch fixes the update_vsyscall interface to provide wall_to_monotonic, allowing wall_to_monotonic to be made static as planned in Documentation/feature-removal-schedule.txt Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Anton Blanchard <anton@samba.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Tony Luck <tony.luck@intel.com> LKML-Reference: <1279068988-21864-7-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- arch/ia64/kernel/time.c | 7 ++++--- arch/powerpc/kernel/time.c | 8 ++++---- arch/s390/kernel/time.c | 8 ++++---- arch/x86/kernel/vsyscall_64.c | 6 +++--- include/linux/clocksource.h | 6 ++++-- kernel/time/timekeeping.c | 9 ++++++--- 6 files changed, 25 insertions(+), 19 deletions(-) diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c index 653b3c4..ed6f22e 100644 --- a/arch/ia64/kernel/time.c +++ b/arch/ia64/kernel/time.c @@ -471,7 +471,8 @@ void update_vsyscall_tz(void) { } -void update_vsyscall(struct timespec *wall, struct clocksource *c, u32 mult) +void update_vsyscall(struct timespec *wall, struct timespec *wtm, + struct clocksource *c, u32 mult) { unsigned long flags; @@ -487,9 +488,9 @@ void update_vsyscall(struct timespec *wall, struct clocksource *c, u32 mult) /* copy kernel time structures */ fsyscall_gtod_data.wall_time.tv_sec = wall->tv_sec; fsyscall_gtod_data.wall_time.tv_nsec = wall->tv_nsec; - fsyscall_gtod_data.monotonic_time.tv_sec = wall_to_monotonic.tv_sec + fsyscall_gtod_data.monotonic_time.tv_sec = wtm->tv_sec + wall->tv_sec; - fsyscall_gtod_data.monotonic_time.tv_nsec = wall_to_monotonic.tv_nsec + fsyscall_gtod_data.monotonic_time.tv_nsec = wtm->tv_nsec + wall->tv_nsec; /* normalize */ diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 0711d60..e215f76 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -849,8 +849,8 @@ static cycle_t timebase_read(struct clocksource *cs) return (cycle_t)get_tb(); } -void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, - u32 mult) +void update_vsyscall(struct timespec *wall_time, struct timespec *wtm, + struct clocksource *clock, u32 mult) { u64 new_tb_to_xs, new_stamp_xsec; @@ -882,8 +882,8 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, vdso_data->tb_orig_stamp = clock->cycle_last; vdso_data->stamp_xsec = new_stamp_xsec; vdso_data->tb_to_xs = new_tb_to_xs; - vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; - vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; + vdso_data->wtom_clock_sec = wtm->tv_sec; + vdso_data->wtom_clock_nsec = wtm->tv_nsec; vdso_data->stamp_xtime = *wall_time; smp_wmb(); ++(vdso_data->tb_update_count); diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index a2163c9..aeb30c6 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -207,8 +207,8 @@ struct clocksource * __init clocksource_default_clock(void) return &clocksource_tod; } -void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, - u32 mult) +void update_vsyscall(struct timespec *wall_time, struct timespec *wtm, + struct clocksource *clock, u32 mult) { if (clock != &clocksource_tod) return; @@ -219,8 +219,8 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, vdso_data->xtime_tod_stamp = clock->cycle_last; vdso_data->xtime_clock_sec = wall_time->tv_sec; vdso_data->xtime_clock_nsec = wall_time->tv_nsec; - vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; - vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; + vdso_data->wtom_clock_sec = wtm->tv_sec; + vdso_data->wtom_clock_nsec = wtm->tv_nsec; vdso_data->ntp_mult = mult; smp_wmb(); ++vdso_data->tb_update_count; diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index dce0c3c..dcbb28c 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -73,8 +73,8 @@ void update_vsyscall_tz(void) write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags); } -void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, - u32 mult) +void update_vsyscall(struct timespec *wall_time, struct timespec *wtm, + struct clocksource *clock, u32 mult) { unsigned long flags; @@ -87,7 +87,7 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, vsyscall_gtod_data.clock.shift = clock->shift; vsyscall_gtod_data.wall_time_sec = wall_time->tv_sec; vsyscall_gtod_data.wall_time_nsec = wall_time->tv_nsec; - vsyscall_gtod_data.wall_to_monotonic = wall_to_monotonic; + vsyscall_gtod_data.wall_to_monotonic = *wtm; vsyscall_gtod_data.wall_time_coarse = __current_kernel_time(); write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags); } diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 5ea3c60..21677d9 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -313,11 +313,13 @@ clocksource_calc_mult_shift(struct clocksource *cs, u32 freq, u32 minsec) #ifdef CONFIG_GENERIC_TIME_VSYSCALL extern void -update_vsyscall(struct timespec *ts, struct clocksource *c, u32 mult); +update_vsyscall(struct timespec *ts, struct timespec *wtm, + struct clocksource *c, u32 mult); extern void update_vsyscall_tz(void); #else static inline void -update_vsyscall(struct timespec *ts, struct clocksource *c, u32 mult) +update_vsyscall(struct timespec *ts, struct timespec *wtm, + struct clocksource *c, u32 mult) { } diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 73edd40..b15c3ac 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -170,7 +170,8 @@ void timekeeping_leap_insert(int leapsecond) { xtime.tv_sec += leapsecond; wall_to_monotonic.tv_sec -= leapsecond; - update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult); + update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, + timekeeper.mult); } /** @@ -326,7 +327,8 @@ int do_settimeofday(struct timespec *tv) timekeeper.ntp_error = 0; ntp_clear(); - update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult); + update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, + timekeeper.mult); write_sequnlock_irqrestore(&xtime_lock, flags); @@ -809,7 +811,8 @@ void update_wall_time(void) } /* check to see if there is a new clocksource to use */ - update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult); + update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, + timekeeper.mult); } /** ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [tip:timers/clocksource] powerpc: Cleanup xtime usage 2010-07-14 0:56 ` [PATCH 05/11] powerpc: Cleanup xtime usage John Stultz 2010-07-14 0:56 ` [PATCH 06/11] Fix update_vsyscall to provide wall_to_monotonic offset John Stultz @ 2010-07-27 10:47 ` tip-bot for John Stultz 1 sibling, 0 replies; 35+ messages in thread From: tip-bot for John Stultz @ 2010-07-27 10:47 UTC (permalink / raw) To: linux-tip-commits; +Cc: linux-kernel, anton, paulus, hpa, mingo, johnstul, tglx Commit-ID: 06d518e3dfb25334282c7e38b4d7a4eada215f6d Gitweb: http://git.kernel.org/tip/06d518e3dfb25334282c7e38b4d7a4eada215f6d Author: John Stultz <johnstul@us.ibm.com> AuthorDate: Tue, 13 Jul 2010 17:56:22 -0700 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Tue, 27 Jul 2010 12:40:54 +0200 powerpc: Cleanup xtime usage This removes powerpc's direct xtime usage, allowing for further generic timeekeping cleanups Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Anton Blanchard <anton@samba.org> LKML-Reference: <1279068988-21864-6-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- arch/powerpc/kernel/time.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 6fcd648..0711d60 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -864,9 +864,9 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, /* XXX this assumes clock->shift == 22 */ /* 4611686018 ~= 2^(20+64-22) / 1e9 */ new_tb_to_xs = (u64) mult * 4611686018ULL; - new_stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC; + new_stamp_xsec = (u64) wall_time->tv_nsec * XSEC_PER_SEC; do_div(new_stamp_xsec, 1000000000); - new_stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC; + new_stamp_xsec += (u64) wall_time->tv_sec * XSEC_PER_SEC; /* * tb_update_count is used to allow the userspace gettimeofday code @@ -884,7 +884,7 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, vdso_data->tb_to_xs = new_tb_to_xs; vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; - vdso_data->stamp_xtime = xtime; + vdso_data->stamp_xtime = *wall_time; smp_wmb(); ++(vdso_data->tb_update_count); } @@ -1093,7 +1093,7 @@ void __init time_init(void) vdso_data->tb_orig_stamp = tb_last_jiffy; vdso_data->tb_update_count = 0; vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; - vdso_data->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC; + vdso_data->stamp_xsec = (u64) get_seconds() * XSEC_PER_SEC; vdso_data->tb_to_xs = tb_to_xs; write_sequnlock_irqrestore(&xtime_lock, flags); ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [tip:timers/clocksource] powerpc: Simplify update_vsyscall 2010-07-14 0:56 ` [PATCH 04/11] powerpc: Simplify update_vsyscall John Stultz 2010-07-14 0:56 ` [PATCH 05/11] powerpc: Cleanup xtime usage John Stultz @ 2010-07-27 10:46 ` tip-bot for John Stultz 2010-07-27 23:41 ` Paul Mackerras 2 siblings, 0 replies; 35+ messages in thread From: tip-bot for John Stultz @ 2010-07-27 10:46 UTC (permalink / raw) To: linux-tip-commits; +Cc: linux-kernel, paulus, anton, hpa, mingo, johnstul, tglx Commit-ID: b0797b60d0067fe437baa97a743c7d9de98fd769 Gitweb: http://git.kernel.org/tip/b0797b60d0067fe437baa97a743c7d9de98fd769 Author: John Stultz <johnstul@us.ibm.com> AuthorDate: Tue, 13 Jul 2010 17:56:21 -0700 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Tue, 27 Jul 2010 12:40:54 +0200 powerpc: Simplify update_vsyscall Currently powerpc's update_vsyscall calls an inline update_gtod. However, both are straightforward, and there are no other users, so this patch merges update_gtod into update_vsyscall. Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Anton Blanchard <anton@samba.org> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1279068988-21864-5-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- arch/powerpc/kernel/time.c | 55 ++++++++++++++++++++------------------------ 1 files changed, 25 insertions(+), 30 deletions(-) diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 0441bbd..6fcd648 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -423,30 +423,6 @@ void udelay(unsigned long usecs) } EXPORT_SYMBOL(udelay); -static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec, - u64 new_tb_to_xs) -{ - /* - * tb_update_count is used to allow the userspace gettimeofday code - * to assure itself that it sees a consistent view of the tb_to_xs and - * stamp_xsec variables. It reads the tb_update_count, then reads - * tb_to_xs and stamp_xsec and then reads tb_update_count again. If - * the two values of tb_update_count match and are even then the - * tb_to_xs and stamp_xsec values are consistent. If not, then it - * loops back and reads them again until this criteria is met. - * We expect the caller to have done the first increment of - * vdso_data->tb_update_count already. - */ - vdso_data->tb_orig_stamp = new_tb_stamp; - vdso_data->stamp_xsec = new_stamp_xsec; - vdso_data->tb_to_xs = new_tb_to_xs; - vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; - vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; - vdso_data->stamp_xtime = xtime; - smp_wmb(); - ++(vdso_data->tb_update_count); -} - #ifdef CONFIG_SMP unsigned long profile_pc(struct pt_regs *regs) { @@ -876,7 +852,7 @@ static cycle_t timebase_read(struct clocksource *cs) void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, u32 mult) { - u64 t2x, stamp_xsec; + u64 new_tb_to_xs, new_stamp_xsec; if (clock != &clocksource_timebase) return; @@ -887,11 +863,30 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, /* XXX this assumes clock->shift == 22 */ /* 4611686018 ~= 2^(20+64-22) / 1e9 */ - t2x = (u64) mult * 4611686018ULL; - stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC; - do_div(stamp_xsec, 1000000000); - stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC; - update_gtod(clock->cycle_last, stamp_xsec, t2x); + new_tb_to_xs = (u64) mult * 4611686018ULL; + new_stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC; + do_div(new_stamp_xsec, 1000000000); + new_stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC; + + /* + * tb_update_count is used to allow the userspace gettimeofday code + * to assure itself that it sees a consistent view of the tb_to_xs and + * stamp_xsec variables. It reads the tb_update_count, then reads + * tb_to_xs and stamp_xsec and then reads tb_update_count again. If + * the two values of tb_update_count match and are even then the + * tb_to_xs and stamp_xsec values are consistent. If not, then it + * loops back and reads them again until this criteria is met. + * We expect the caller to have done the first increment of + * vdso_data->tb_update_count already. + */ + vdso_data->tb_orig_stamp = clock->cycle_last; + vdso_data->stamp_xsec = new_stamp_xsec; + vdso_data->tb_to_xs = new_tb_to_xs; + vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; + vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; + vdso_data->stamp_xtime = xtime; + smp_wmb(); + ++(vdso_data->tb_update_count); } void update_vsyscall_tz(void) ^ permalink raw reply related [flat|nested] 35+ messages in thread
* Re: [PATCH 04/11] powerpc: Simplify update_vsyscall 2010-07-14 0:56 ` [PATCH 04/11] powerpc: Simplify update_vsyscall John Stultz @ 2010-07-27 23:41 ` Paul Mackerras 2010-07-27 10:46 ` [tip:timers/clocksource] powerpc: Simplify update_vsyscall tip-bot for John Stultz 2010-07-27 23:41 ` Paul Mackerras 2 siblings, 0 replies; 35+ messages in thread From: Paul Mackerras @ 2010-07-27 23:41 UTC (permalink / raw) To: John Stultz Cc: linuxppc-dev, Thomas Gleixner, Ingo Molnar, LKML, Anton Blanchard On Tue, Jul 13, 2010 at 05:56:21PM -0700, John Stultz wrote: > Currently powerpc's update_vsyscall calls an inline update_gtod. > However, both are straightforward, and there are no other users, > so this patch merges update_gtod into update_vsyscall. > > Compiles, but otherwise untested. This and the following two patches will cause interesting conflicts with two commits in Ben Herrenschmidt's powerpc.git next branch, specifically 8fd63a9e ("powerpc: Rework VDSO gettimeofday to prevent time going backwards") and c1aa687d ("powerpc: Clean up obsolete code relating to decrementer and timebase") from me. In fact the first of those two commits includes changes equivalent to those in your 5/11 patch ("powerpc: Cleanup xtime usage"), as far as I can see. BTW, BenH's tree is at: git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc.git Paul. ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 04/11] powerpc: Simplify update_vsyscall @ 2010-07-27 23:41 ` Paul Mackerras 0 siblings, 0 replies; 35+ messages in thread From: Paul Mackerras @ 2010-07-27 23:41 UTC (permalink / raw) To: John Stultz Cc: LKML, Anton Blanchard, Thomas Gleixner, linuxppc-dev, Ingo Molnar On Tue, Jul 13, 2010 at 05:56:21PM -0700, John Stultz wrote: > Currently powerpc's update_vsyscall calls an inline update_gtod. > However, both are straightforward, and there are no other users, > so this patch merges update_gtod into update_vsyscall. > > Compiles, but otherwise untested. This and the following two patches will cause interesting conflicts with two commits in Ben Herrenschmidt's powerpc.git next branch, specifically 8fd63a9e ("powerpc: Rework VDSO gettimeofday to prevent time going backwards") and c1aa687d ("powerpc: Clean up obsolete code relating to decrementer and timebase") from me. In fact the first of those two commits includes changes equivalent to those in your 5/11 patch ("powerpc: Cleanup xtime usage"), as far as I can see. BTW, BenH's tree is at: git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc.git Paul. ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 04/11] powerpc: Simplify update_vsyscall 2010-07-27 23:41 ` Paul Mackerras @ 2010-07-28 1:33 ` john stultz -1 siblings, 0 replies; 35+ messages in thread From: john stultz @ 2010-07-28 1:33 UTC (permalink / raw) To: Paul Mackerras Cc: linuxppc-dev, Thomas Gleixner, Ingo Molnar, LKML, Anton Blanchard [-- Attachment #1: Type: text/plain, Size: 1792 bytes --] On Wed, 2010-07-28 at 09:41 +1000, Paul Mackerras wrote: > On Tue, Jul 13, 2010 at 05:56:21PM -0700, John Stultz wrote: > > > Currently powerpc's update_vsyscall calls an inline update_gtod. > > However, both are straightforward, and there are no other users, > > so this patch merges update_gtod into update_vsyscall. > > > > Compiles, but otherwise untested. > > This and the following two patches will cause interesting conflicts > with two commits in Ben Herrenschmidt's powerpc.git next branch, > specifically 8fd63a9e ("powerpc: Rework VDSO gettimeofday to prevent > time going backwards") and c1aa687d ("powerpc: Clean up obsolete code > relating to decrementer and timebase") from me. In fact the first of > those two commits includes changes equivalent to those in your 5/11 > patch ("powerpc: Cleanup xtime usage"), as far as I can see. Ahh.. Right.. I guess I should have remembered you were working on those changes (even though I don't think I saw the final results sent to lkml or anything). Sorry about that. > BTW, BenH's tree is at: > > git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc.git So I've cherry picked the two changes from the ppc tree, applied them onto linus' git tree and then rebased my changes ontop of them. The net of the change to the patch set: Added to the head of the patch queue: powerpc: Rework VDSO gettimeofday to prevent time going backwards powerpc: Clean up obsolete code relating to decrementer and timebase Modified to resolve collision: powerpc: Simplify update_vsyscall Dropped (as earlier patches already made equivalent changes): powerpc: Cleanup xtime usage The full set is in the attached tarball. Thomas, would you consider re-adding these? Hopefully that will avoid any -next collisions. thanks -john [-- Attachment #2: patches.tar.bz2 --] [-- Type: application/x-bzip-compressed-tar, Size: 21405 bytes --] ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 04/11] powerpc: Simplify update_vsyscall @ 2010-07-28 1:33 ` john stultz 0 siblings, 0 replies; 35+ messages in thread From: john stultz @ 2010-07-28 1:33 UTC (permalink / raw) To: Paul Mackerras Cc: LKML, Anton Blanchard, Thomas Gleixner, linuxppc-dev, Ingo Molnar [-- Attachment #1: Type: text/plain, Size: 1792 bytes --] On Wed, 2010-07-28 at 09:41 +1000, Paul Mackerras wrote: > On Tue, Jul 13, 2010 at 05:56:21PM -0700, John Stultz wrote: > > > Currently powerpc's update_vsyscall calls an inline update_gtod. > > However, both are straightforward, and there are no other users, > > so this patch merges update_gtod into update_vsyscall. > > > > Compiles, but otherwise untested. > > This and the following two patches will cause interesting conflicts > with two commits in Ben Herrenschmidt's powerpc.git next branch, > specifically 8fd63a9e ("powerpc: Rework VDSO gettimeofday to prevent > time going backwards") and c1aa687d ("powerpc: Clean up obsolete code > relating to decrementer and timebase") from me. In fact the first of > those two commits includes changes equivalent to those in your 5/11 > patch ("powerpc: Cleanup xtime usage"), as far as I can see. Ahh.. Right.. I guess I should have remembered you were working on those changes (even though I don't think I saw the final results sent to lkml or anything). Sorry about that. > BTW, BenH's tree is at: > > git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc.git So I've cherry picked the two changes from the ppc tree, applied them onto linus' git tree and then rebased my changes ontop of them. The net of the change to the patch set: Added to the head of the patch queue: powerpc: Rework VDSO gettimeofday to prevent time going backwards powerpc: Clean up obsolete code relating to decrementer and timebase Modified to resolve collision: powerpc: Simplify update_vsyscall Dropped (as earlier patches already made equivalent changes): powerpc: Cleanup xtime usage The full set is in the attached tarball. Thomas, would you consider re-adding these? Hopefully that will avoid any -next collisions. thanks -john [-- Attachment #2: patches.tar.bz2 --] [-- Type: application/x-bzip-compressed-tar, Size: 21405 bytes --] ^ permalink raw reply [flat|nested] 35+ messages in thread
* [tip:timers/clocksource] time: Kill off CONFIG_GENERIC_TIME 2010-07-14 0:56 ` [PATCH 03/11] time: Kill off CONFIG_GENERIC_TIME John Stultz 2010-07-14 0:56 ` [PATCH 04/11] powerpc: Simplify update_vsyscall John Stultz @ 2010-07-27 10:46 ` tip-bot for John Stultz 1 sibling, 0 replies; 35+ messages in thread From: tip-bot for John Stultz @ 2010-07-27 10:46 UTC (permalink / raw) To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, johnstul, tglx Commit-ID: 592913ecb87a9e06f98ddb55b298f1a66bf94c6b Gitweb: http://git.kernel.org/tip/592913ecb87a9e06f98ddb55b298f1a66bf94c6b Author: John Stultz <johnstul@us.ibm.com> AuthorDate: Tue, 13 Jul 2010 17:56:20 -0700 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Tue, 27 Jul 2010 12:40:54 +0200 time: Kill off CONFIG_GENERIC_TIME Now that all arches have been converted over to use generic time via clocksources or arch_gettimeoffset(), we can remove the GENERIC_TIME config option and simplify the generic code. Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1279068988-21864-4-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- Documentation/kernel-parameters.txt | 3 +- arch/alpha/Kconfig | 4 -- arch/arm/Kconfig | 4 -- arch/avr32/Kconfig | 3 -- arch/blackfin/Kconfig | 3 -- arch/cris/Kconfig | 3 -- arch/frv/Kconfig | 4 -- arch/h8300/Kconfig | 4 -- arch/ia64/Kconfig | 4 -- arch/m32r/Kconfig | 3 -- arch/m68k/Kconfig | 3 -- arch/m68knommu/Kconfig | 4 -- arch/microblaze/Kconfig | 3 -- arch/mips/Kconfig | 4 -- arch/mn10300/Kconfig | 3 -- arch/parisc/Kconfig | 4 -- arch/powerpc/Kconfig | 3 -- arch/s390/Kconfig | 3 -- arch/score/Kconfig | 3 -- arch/sh/Kconfig | 3 -- arch/sparc/Kconfig | 3 -- arch/um/Kconfig.common | 4 -- arch/x86/Kconfig | 5 +-- arch/xtensa/Kconfig | 3 -- drivers/Makefile | 4 ++- drivers/acpi/acpi_pad.c | 2 +- drivers/acpi/processor_idle.c | 2 +- drivers/misc/Kconfig | 4 +- kernel/time.c | 16 ---------- kernel/time/Kconfig | 4 +- kernel/time/clocksource.c | 4 +- kernel/time/timekeeping.c | 55 ++-------------------------------- kernel/trace/Kconfig | 4 +- 33 files changed, 19 insertions(+), 159 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 2b2407d..8abdfd7 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -73,7 +73,6 @@ parameter is applicable: MTD MTD (Memory Technology Device) support is enabled. NET Appropriate network support is enabled. NUMA NUMA support is enabled. - GENERIC_TIME The generic timeofday code is enabled. NFS Appropriate NFS support is enabled. OSS OSS sound support is enabled. PV_OPS A paravirtualized kernel is enabled. @@ -468,7 +467,7 @@ and is between 256 and 4096 characters. It is defined in the file clocksource is not available, it defaults to PIT. Format: { pit | tsc | cyclone | pmtmr } - clocksource= [GENERIC_TIME] Override the default clocksource + clocksource= Override the default clocksource Format: <string> Override the default clocksource and use the clocksource with the name specified. diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig index 3e2e540..b9647bb 100644 --- a/arch/alpha/Kconfig +++ b/arch/alpha/Kconfig @@ -47,10 +47,6 @@ config GENERIC_CALIBRATE_DELAY bool default y -config GENERIC_TIME - bool - default y - config GENERIC_CMOS_UPDATE def_bool y diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 98922f7..655b4ae 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -41,10 +41,6 @@ config SYS_SUPPORTS_APM_EMULATION config GENERIC_GPIO bool -config GENERIC_TIME - bool - default y - config ARCH_USES_GETTIMEOFFSET bool default n diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig index f2b3193..f515727 100644 --- a/arch/avr32/Kconfig +++ b/arch/avr32/Kconfig @@ -45,9 +45,6 @@ config GENERIC_IRQ_PROBE config RWSEM_GENERIC_SPINLOCK def_bool y -config GENERIC_TIME - def_bool y - config GENERIC_CLOCKEVENTS def_bool y diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig index f66294b..c88fd35 100644 --- a/arch/blackfin/Kconfig +++ b/arch/blackfin/Kconfig @@ -614,9 +614,6 @@ comment "Kernel Timer/Scheduler" source kernel/Kconfig.hz -config GENERIC_TIME - def_bool y - config GENERIC_CLOCKEVENTS bool "Generic clock events" default y diff --git a/arch/cris/Kconfig b/arch/cris/Kconfig index e25bf44..887ef85 100644 --- a/arch/cris/Kconfig +++ b/arch/cris/Kconfig @@ -20,9 +20,6 @@ config RWSEM_GENERIC_SPINLOCK config RWSEM_XCHGADD_ALGORITHM bool -config GENERIC_TIME - def_bool y - config GENERIC_CMOS_UPDATE def_bool y diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig index 4b5830b..16399bd 100644 --- a/arch/frv/Kconfig +++ b/arch/frv/Kconfig @@ -40,10 +40,6 @@ config GENERIC_HARDIRQS_NO__DO_IRQ bool default y -config GENERIC_TIME - bool - default y - config TIME_LOW_RES bool default y diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig index 53cc669..988b6ff 100644 --- a/arch/h8300/Kconfig +++ b/arch/h8300/Kconfig @@ -62,10 +62,6 @@ config GENERIC_CALIBRATE_DELAY bool default y -config GENERIC_TIME - bool - default y - config GENERIC_BUG bool depends on BUG diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index 9561082..8711d13 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -82,10 +82,6 @@ config GENERIC_CALIBRATE_DELAY bool default y -config GENERIC_TIME - bool - default y - config GENERIC_TIME_VSYSCALL bool default y diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig index 3a9319f..836abbb 100644 --- a/arch/m32r/Kconfig +++ b/arch/m32r/Kconfig @@ -44,9 +44,6 @@ config HZ int default 100 -config GENERIC_TIME - def_bool y - config ARCH_USES_GETTIMEOFFSET def_bool y diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig index 2e3737b..8030e24 100644 --- a/arch/m68k/Kconfig +++ b/arch/m68k/Kconfig @@ -59,9 +59,6 @@ config HZ int default 100 -config GENERIC_TIME - def_bool y - config ARCH_USES_GETTIMEOFFSET def_bool y diff --git a/arch/m68knommu/Kconfig b/arch/m68knommu/Kconfig index efeb603..2609c39 100644 --- a/arch/m68knommu/Kconfig +++ b/arch/m68knommu/Kconfig @@ -63,10 +63,6 @@ config GENERIC_CALIBRATE_DELAY bool default y -config GENERIC_TIME - bool - default y - config GENERIC_CMOS_UPDATE bool default y diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig index 505a085..14f03ce 100644 --- a/arch/microblaze/Kconfig +++ b/arch/microblaze/Kconfig @@ -48,9 +48,6 @@ config GENERIC_IRQ_PROBE config GENERIC_CALIBRATE_DELAY def_bool y -config GENERIC_TIME - def_bool y - config GENERIC_TIME_VSYSCALL def_bool n diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index cdaae94..01c44cb 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -733,10 +733,6 @@ config GENERIC_CLOCKEVENTS bool default y -config GENERIC_TIME - bool - default y - config GENERIC_CMOS_UPDATE bool default y diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig index 1c4565a..444b9f9 100644 --- a/arch/mn10300/Kconfig +++ b/arch/mn10300/Kconfig @@ -46,9 +46,6 @@ config GENERIC_FIND_NEXT_BIT config GENERIC_HWEIGHT def_bool y -config GENERIC_TIME - def_bool y - config GENERIC_BUG def_bool y diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index 05a366a..907417d 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -66,10 +66,6 @@ config GENERIC_CALIBRATE_DELAY bool default y -config GENERIC_TIME - bool - default y - config TIME_LOW_RES bool depends on SMP diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 2031a28..25e6bf4 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -29,9 +29,6 @@ config MMU config GENERIC_CMOS_UPDATE def_bool y -config GENERIC_TIME - def_bool y - config GENERIC_TIME_VSYSCALL def_bool y diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index bee1c0f..f0777a4 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -40,9 +40,6 @@ config ARCH_HAS_ILOG2_U64 config GENERIC_HWEIGHT def_bool y -config GENERIC_TIME - def_bool y - config GENERIC_TIME_VSYSCALL def_bool y diff --git a/arch/score/Kconfig b/arch/score/Kconfig index 55d413e..be4a155 100644 --- a/arch/score/Kconfig +++ b/arch/score/Kconfig @@ -55,9 +55,6 @@ config GENERIC_CALIBRATE_DELAY config GENERIC_CLOCKEVENTS def_bool y -config GENERIC_TIME - def_bool y - config SCHED_NO_NO_OMIT_FRAME_POINTER def_bool y diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index 82868fe..33990fa 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -98,9 +98,6 @@ config GENERIC_CALIBRATE_DELAY config GENERIC_IOMAP bool -config GENERIC_TIME - def_bool y - config GENERIC_CLOCKEVENTS def_bool y diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig index c0015db..1cd0d9d 100644 --- a/arch/sparc/Kconfig +++ b/arch/sparc/Kconfig @@ -66,9 +66,6 @@ config BITS default 32 if SPARC32 default 64 if SPARC64 -config GENERIC_TIME - def_bool y - config ARCH_USES_GETTIMEOFFSET bool default y if SPARC32 diff --git a/arch/um/Kconfig.common b/arch/um/Kconfig.common index 0d207e7..7c8e277 100644 --- a/arch/um/Kconfig.common +++ b/arch/um/Kconfig.common @@ -55,10 +55,6 @@ config GENERIC_BUG default y depends on BUG -config GENERIC_TIME - bool - default y - config GENERIC_CLOCKEVENTS bool default y diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index dcb0593..546b610a 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -72,9 +72,6 @@ config ARCH_DEFCONFIG default "arch/x86/configs/i386_defconfig" if X86_32 default "arch/x86/configs/x86_64_defconfig" if X86_64 -config GENERIC_TIME - def_bool y - config GENERIC_CMOS_UPDATE def_bool y @@ -2046,7 +2043,7 @@ config SCx200 config SCx200HR_TIMER tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" - depends on SCx200 && GENERIC_TIME + depends on SCx200 default y ---help--- This driver provides a clocksource built upon the on-chip diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig index ebe228d..0859bfd 100644 --- a/arch/xtensa/Kconfig +++ b/arch/xtensa/Kconfig @@ -48,9 +48,6 @@ config HZ int default 100 -config GENERIC_TIME - def_bool y - source "init/Kconfig" source "kernel/Kconfig.freezer" diff --git a/drivers/Makefile b/drivers/Makefile index 91874e0..ae47344 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -101,7 +101,9 @@ obj-y += firmware/ obj-$(CONFIG_CRYPTO) += crypto/ obj-$(CONFIG_SUPERH) += sh/ obj-$(CONFIG_ARCH_SHMOBILE) += sh/ -obj-$(CONFIG_GENERIC_TIME) += clocksource/ +ifndef CONFIG_ARCH_USES_GETTIMEOFFSET +obj-y += clocksource/ +endif obj-$(CONFIG_DMA_ENGINE) += dma/ obj-$(CONFIG_DCA) += dca/ obj-$(CONFIG_HID) += hid/ diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c index 446aced..b76848c 100644 --- a/drivers/acpi/acpi_pad.c +++ b/drivers/acpi/acpi_pad.c @@ -77,7 +77,7 @@ static void power_saving_mwait_init(void) power_saving_mwait_eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) | (highest_subcstate - 1); -#if defined(CONFIG_GENERIC_TIME) && defined(CONFIG_X86) +#if defined(CONFIG_X86) switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_AMD: case X86_VENDOR_INTEL: diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index e9a8026..294e10b 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -264,7 +264,7 @@ int acpi_processor_resume(struct acpi_device * device) return 0; } -#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) +#if defined(CONFIG_X86) static void tsc_check_state(int state) { switch (boot_cpu_data.x86_vendor) { diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index 26386a9..5b9ba48 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -72,7 +72,7 @@ config ATMEL_TCLIB config ATMEL_TCB_CLKSRC bool "TC Block Clocksource" - depends on ATMEL_TCLIB && GENERIC_TIME + depends on ATMEL_TCLIB default y help Select this to get a high precision clocksource based on a @@ -240,7 +240,7 @@ config CS5535_MFGPT_DEFAULT_IRQ config CS5535_CLOCK_EVENT_SRC tristate "CS5535/CS5536 high-res timer (MFGPT) events" - depends on GENERIC_TIME && GENERIC_CLOCKEVENTS && CS5535_MFGPT + depends on GENERIC_CLOCKEVENTS && CS5535_MFGPT help This driver provides a clock event source based on the MFGPT timer(s) in the CS5535 and CS5536 companion chips. diff --git a/kernel/time.c b/kernel/time.c index 848b1c2..ba9b338 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -300,22 +300,6 @@ struct timespec timespec_trunc(struct timespec t, unsigned gran) } EXPORT_SYMBOL(timespec_trunc); -#ifndef CONFIG_GENERIC_TIME -/* - * Simulate gettimeofday using do_gettimeofday which only allows a timeval - * and therefore only yields usec accuracy - */ -void getnstimeofday(struct timespec *tv) -{ - struct timeval x; - - do_gettimeofday(&x); - tv->tv_sec = x.tv_sec; - tv->tv_nsec = x.tv_usec * NSEC_PER_USEC; -} -EXPORT_SYMBOL_GPL(getnstimeofday); -#endif - /* Converts Gregorian date to seconds since 1970-01-01 00:00:00. * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index 95ed429..f06a8a3 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -6,7 +6,7 @@ config TICK_ONESHOT config NO_HZ bool "Tickless System (Dynamic Ticks)" - depends on GENERIC_TIME && GENERIC_CLOCKEVENTS + depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS select TICK_ONESHOT help This option enables a tickless system: timer interrupts will @@ -15,7 +15,7 @@ config NO_HZ config HIGH_RES_TIMERS bool "High Resolution Timer Support" - depends on GENERIC_TIME && GENERIC_CLOCKEVENTS + depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS select TICK_ONESHOT help This option enables high resolution timer support. If your diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index f08e99c..c543d21 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -531,7 +531,7 @@ static u64 clocksource_max_deferment(struct clocksource *cs) return max_nsecs - (max_nsecs >> 5); } -#ifdef CONFIG_GENERIC_TIME +#ifndef CONFIG_ARCH_USES_GETTIMEOFFSET /** * clocksource_select - Select the best clocksource available @@ -577,7 +577,7 @@ static void clocksource_select(void) } } -#else /* CONFIG_GENERIC_TIME */ +#else /* !CONFIG_ARCH_USES_GETTIMEOFFSET */ static inline void clocksource_select(void) { } diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 623fe3d..73edd40 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -173,8 +173,6 @@ void timekeeping_leap_insert(int leapsecond) update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult); } -#ifdef CONFIG_GENERIC_TIME - /** * timekeeping_forward_now - update clock to the current time * @@ -376,52 +374,6 @@ void timekeeping_notify(struct clocksource *clock) tick_clock_notify(); } -#else /* GENERIC_TIME */ - -static inline void timekeeping_forward_now(void) { } - -/** - * ktime_get - get the monotonic time in ktime_t format - * - * returns the time in ktime_t format - */ -ktime_t ktime_get(void) -{ - struct timespec now; - - ktime_get_ts(&now); - - return timespec_to_ktime(now); -} -EXPORT_SYMBOL_GPL(ktime_get); - -/** - * ktime_get_ts - get the monotonic clock in timespec format - * @ts: pointer to timespec variable - * - * The function calculates the monotonic clock from the realtime - * clock and the wall_to_monotonic offset and stores the result - * in normalized timespec format in the variable pointed to by @ts. - */ -void ktime_get_ts(struct timespec *ts) -{ - struct timespec tomono; - unsigned long seq; - - do { - seq = read_seqbegin(&xtime_lock); - getnstimeofday(ts); - tomono = wall_to_monotonic; - - } while (read_seqretry(&xtime_lock, seq)); - - set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, - ts->tv_nsec + tomono.tv_nsec); -} -EXPORT_SYMBOL_GPL(ktime_get_ts); - -#endif /* !GENERIC_TIME */ - /** * ktime_get_real - get the real (wall-) time in ktime_t format * @@ -784,10 +736,11 @@ void update_wall_time(void) return; clock = timekeeper.clock; -#ifdef CONFIG_GENERIC_TIME - offset = (clock->read(clock) - clock->cycle_last) & clock->mask; -#else + +#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET offset = timekeeper.cycle_interval; +#else + offset = (clock->read(clock) - clock->cycle_last) & clock->mask; #endif timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift; diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 8b1797c..7531dda 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -153,7 +153,7 @@ config IRQSOFF_TRACER bool "Interrupts-off Latency Tracer" default n depends on TRACE_IRQFLAGS_SUPPORT - depends on GENERIC_TIME + depends on !ARCH_USES_GETTIMEOFFSET select TRACE_IRQFLAGS select GENERIC_TRACER select TRACER_MAX_TRACE @@ -175,7 +175,7 @@ config IRQSOFF_TRACER config PREEMPT_TRACER bool "Preemption-off Latency Tracer" default n - depends on GENERIC_TIME + depends on !ARCH_USES_GETTIMEOFFSET depends on PREEMPT select GENERIC_TRACER select TRACER_MAX_TRACE ^ permalink raw reply related [flat|nested] 35+ messages in thread
* [tip:timers/clocksource] time: Implement timespec_add 2010-07-14 0:56 ` [PATCH 02/11] Implement timespec_add John Stultz 2010-07-14 0:56 ` [PATCH 03/11] time: Kill off CONFIG_GENERIC_TIME John Stultz @ 2010-07-27 10:46 ` tip-bot for John Stultz 1 sibling, 0 replies; 35+ messages in thread From: tip-bot for John Stultz @ 2010-07-27 10:46 UTC (permalink / raw) To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, johnstul, tglx Commit-ID: ce3bf7ab22527183634a76512d9854a38615e4d5 Gitweb: http://git.kernel.org/tip/ce3bf7ab22527183634a76512d9854a38615e4d5 Author: John Stultz <johnstul@us.ibm.com> AuthorDate: Tue, 13 Jul 2010 17:56:19 -0700 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Tue, 27 Jul 2010 12:40:53 +0200 time: Implement timespec_add After accidentally misusing timespec_add_safe, I wanted to make sure we don't accidently trip over that issue again, so I created a simple timespec_add() function which we can use to replace the instances of timespec_add_safe() that don't want the overflow detection. Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1279068988-21864-3-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- include/linux/time.h | 16 ++++++++++++++++ kernel/time/timekeeping.c | 6 +++--- 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/include/linux/time.h b/include/linux/time.h index ea3559f0..9072df8 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -76,9 +76,25 @@ extern unsigned long mktime(const unsigned int year, const unsigned int mon, const unsigned int min, const unsigned int sec); extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec); + +/* + * timespec_add_safe assumes both values are positive and checks + * for overflow. It will return TIME_T_MAX if the reutrn would be + * smaller then either of the arguments. + */ extern struct timespec timespec_add_safe(const struct timespec lhs, const struct timespec rhs); + +static inline struct timespec timespec_add(struct timespec lhs, + struct timespec rhs) +{ + struct timespec ts_delta; + set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec, + lhs.tv_nsec + rhs.tv_nsec); + return ts_delta; +} + /* * sub = lhs - rhs, in normalized form */ diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index caf8d4d..623fe3d 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -579,9 +579,9 @@ static int timekeeping_resume(struct sys_device *dev) if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) { ts = timespec_sub(ts, timekeeping_suspend_time); - xtime = timespec_add_safe(xtime, ts); + xtime = timespec_add(xtime, ts); wall_to_monotonic = timespec_sub(wall_to_monotonic, ts); - total_sleep_time = timespec_add_safe(total_sleep_time, ts); + total_sleep_time = timespec_add(total_sleep_time, ts); } /* re-base the last cycle value */ timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); @@ -887,7 +887,7 @@ EXPORT_SYMBOL_GPL(getboottime); */ void monotonic_to_bootbased(struct timespec *ts) { - *ts = timespec_add_safe(*ts, total_sleep_time); + *ts = timespec_add(*ts, total_sleep_time); } EXPORT_SYMBOL_GPL(monotonic_to_bootbased); ^ permalink raw reply related [flat|nested] 35+ messages in thread
* Re: [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies 2010-07-14 0:56 ` [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies John Stultz 2010-07-14 0:56 ` [PATCH 02/11] Implement timespec_add John Stultz @ 2010-07-14 2:40 ` KOSAKI Motohiro 2010-07-14 16:19 ` john stultz 2010-07-27 10:45 ` [tip:timers/clocksource] " tip-bot for John Stultz 2 siblings, 1 reply; 35+ messages in thread From: KOSAKI Motohiro @ 2010-07-14 2:40 UTC (permalink / raw) To: John Stultz Cc: kosaki.motohiro, LKML, Jiri Olsa, Thomas Gleixner, Oleg Nesterov Hi > Due to vtime calling vgettimeofday(), its possible that an application > could call time();create("stuff",O_RDRW); only to see the file's > creation timestamp to be before the value returned by time. Just dumb question. Almost application are using gettimeofday() instead time(). It mean your fix don't solve almost application. So, Why can't we fix vgettimeofday() vs create() inconsistency? This is just question, I don't intend to disagree you. > > A similar way to reproduce the issue is to compare the vsyscall time() > with the syscall time(), and observe ordering issues. > > The modified test case from Oleg Nesterov below can illustrate this: > > int main(void) > { > time_t sec1,sec2; > do { > sec1 = time(&sec2); > sec2 = syscall(__NR_time, NULL); > } while (sec1 <= sec2); > > printf("vtime: %d.000000\n", sec1); > printf("time: %d.000000\n", sec2); > return 0; > } > > The proper fix is to make vtime use the same time value as > current_kernel_time() (which is exported via update_vsyscall) instead of > vgettime(). > > Thanks to Jiri Olsa for bringing up the issue and catching bugs in > earlier verisons of this fix. > > Signed-off-by: John Stultz <johnstul@us.ibm.com> > > CC: Jiri Olsa <jolsa@redhat.com> > CC: Thomas Gleixner <tglx@linutronix.de> > CC: Oleg Nesterov <oleg@redhat.com> > --- > arch/x86/kernel/vsyscall_64.c | 11 ++++++++--- > 1 files changed, 8 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c > index 1c0c6ab..dce0c3c 100644 > --- a/arch/x86/kernel/vsyscall_64.c > +++ b/arch/x86/kernel/vsyscall_64.c > @@ -169,13 +169,18 @@ int __vsyscall(0) vgettimeofday(struct timeval * tv, struct timezone * tz) > * unlikely */ > time_t __vsyscall(1) vtime(time_t *t) > { > - struct timeval tv; > + unsigned seq; > time_t result; > if (unlikely(!__vsyscall_gtod_data.sysctl_enabled)) > return time_syscall(t); > > - vgettimeofday(&tv, NULL); > - result = tv.tv_sec; > + do { > + seq = read_seqbegin(&__vsyscall_gtod_data.lock); > + > + result = __vsyscall_gtod_data.wall_time_sec; > + > + } while (read_seqretry(&__vsyscall_gtod_data.lock, seq)); > + > if (t) > *t = result; > return result; > -- > 1.6.0.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies 2010-07-14 2:40 ` [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies KOSAKI Motohiro @ 2010-07-14 16:19 ` john stultz 2010-07-15 1:51 ` KOSAKI Motohiro 0 siblings, 1 reply; 35+ messages in thread From: john stultz @ 2010-07-14 16:19 UTC (permalink / raw) To: KOSAKI Motohiro; +Cc: LKML, Jiri Olsa, Thomas Gleixner, Oleg Nesterov On Wed, 2010-07-14 at 11:40 +0900, KOSAKI Motohiro wrote: > Hi > > > Due to vtime calling vgettimeofday(), its possible that an application > > could call time();create("stuff",O_RDRW); only to see the file's > > creation timestamp to be before the value returned by time. > > Just dumb question. > > Almost application are using gettimeofday() instead time(). It mean > your fix don't solve almost application. Correct, filesystem timestamps and gettimeofday can still seem inconsistently ordered. But that is expected. Because of granularity differences (one interface is only tick resolution, the other is clocksource resolution), we can't interleave the two interfaces (time and gettimeofday, respectively) and expect to get ordered results. This is why the fix I'm proposing is important: Filesystem timestamps have always been tick granular, so when vtime() was made clocksource granular (by using vgettime internally) we broke the historic expectation that the time() interface could be interleaved with filesystem operations. Side note: For full nanosecond resolution of the tick-granular timestamps, check out the clock_gettime(CLOCK_REALTIME_COARSE, ...) interface. > So, Why can't we fix vgettimeofday() vs create() inconsistency? > This is just question, I don't intend to disagree you. The only way to make gettimeofday and create consistent is to use gettimeofday clocksource resolution timestamps for files. This however would potentially cause a large performance hit, since each every file timestamp would require a possibly expensive read of the clocksource. thanks -john ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies 2010-07-14 16:19 ` john stultz @ 2010-07-15 1:51 ` KOSAKI Motohiro 2010-07-15 2:46 ` john stultz 2010-07-15 2:51 ` john stultz 0 siblings, 2 replies; 35+ messages in thread From: KOSAKI Motohiro @ 2010-07-15 1:51 UTC (permalink / raw) To: john stultz Cc: kosaki.motohiro, LKML, Jiri Olsa, Thomas Gleixner, Oleg Nesterov > On Wed, 2010-07-14 at 11:40 +0900, KOSAKI Motohiro wrote: > > Hi > > > > > Due to vtime calling vgettimeofday(), its possible that an application > > > could call time();create("stuff",O_RDRW); only to see the file's > > > creation timestamp to be before the value returned by time. > > > > Just dumb question. > > > > Almost application are using gettimeofday() instead time(). It mean > > your fix don't solve almost application. > > Correct, filesystem timestamps and gettimeofday can still seem > inconsistently ordered. But that is expected. > > Because of granularity differences (one interface is only tick > resolution, the other is clocksource resolution), we can't interleave > the two interfaces (time and gettimeofday, respectively) and expect to > get ordered results. hmmm... Yes, times() vs gettimeofday() mekes no sense. nobody want this. but I don't understand why we can ignore gettimeofday() vs file-tiemstamp. > This is why the fix I'm proposing is important: Filesystem timestamps > have always been tick granular, so when vtime() was made clocksource > granular (by using vgettime internally) we broke the historic > expectation that the time() interface could be interleaved with > filesystem operations. > > Side note: For full nanosecond resolution of the tick-granular > timestamps, check out the clock_gettime(CLOCK_REALTIME_COARSE, ...) > interface. > > > > So, Why can't we fix vgettimeofday() vs create() inconsistency? > > This is just question, I don't intend to disagree you. > > The only way to make gettimeofday and create consistent is to use > gettimeofday clocksource resolution timestamps for files. This however > would potentially cause a large performance hit, since each every file > timestamp would require a possibly expensive read of the clocksource. Why clocksource() reading is so slow? the implementation of current tsc clocksource ->read method is here. static cycle_t read_tsc(struct clocksource *cs) { cycle_t ret = (cycle_t)get_cycles(); return ret >= clocksource_tsc.cycle_last ? ret : clocksource_tsc.cycle_last; } It mean, the difference is almost only one rdtsc. And, now we have RELATIME. then crazy atime frequently updating issue has been solved. Can you please elaborate your worry? I think I haven't get which case you worry. Thanks. ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies 2010-07-15 1:51 ` KOSAKI Motohiro @ 2010-07-15 2:46 ` john stultz 2010-07-15 4:41 ` KOSAKI Motohiro 2010-07-15 2:51 ` john stultz 1 sibling, 1 reply; 35+ messages in thread From: john stultz @ 2010-07-15 2:46 UTC (permalink / raw) To: KOSAKI Motohiro; +Cc: LKML, Jiri Olsa, Thomas Gleixner, Oleg Nesterov On Thu, 2010-07-15 at 10:51 +0900, KOSAKI Motohiro wrote: > > On Wed, 2010-07-14 at 11:40 +0900, KOSAKI Motohiro wrote: > > > Hi > > > > > > > Due to vtime calling vgettimeofday(), its possible that an application > > > > could call time();create("stuff",O_RDRW); only to see the file's > > > > creation timestamp to be before the value returned by time. > > > > > > Just dumb question. > > > > > > Almost application are using gettimeofday() instead time(). It mean > > > your fix don't solve almost application. > > > > Correct, filesystem timestamps and gettimeofday can still seem > > inconsistently ordered. But that is expected. > > > > Because of granularity differences (one interface is only tick > > resolution, the other is clocksource resolution), we can't interleave > > the two interfaces (time and gettimeofday, respectively) and expect to > > get ordered results. > > hmmm... > Yes, times() vs gettimeofday() mekes no sense. nobody want this. but > I don't understand why we can ignore gettimeofday() vs file-tiemstamp. So, just to be clear, this discussion is really around the question of "Why don't filesystems use a clocksource-granular (ie: getnstimeofday()) timestamps instead of tick-granular (ie current_kernel_time()) timestamps." However, this is *not* what the patch that started this thread was about. In the patch I'm simply fixing an inconsistency in the vtime interface, where it does not align with what the syscall-time interface provides. The issue was noticed via inconsistencies with filesystem timestamps, but the patch does not change anything to do with filesystem timestamp behavior. > > This is why the fix I'm proposing is important: Filesystem timestamps > > have always been tick granular, so when vtime() was made clocksource > > granular (by using vgettime internally) we broke the historic > > expectation that the time() interface could be interleaved with > > filesystem operations. > > > > Side note: For full nanosecond resolution of the tick-granular > > timestamps, check out the clock_gettime(CLOCK_REALTIME_COARSE, ...) > > interface. > > > > > > > So, Why can't we fix vgettimeofday() vs create() inconsistency? > > > This is just question, I don't intend to disagree you. > > > > The only way to make gettimeofday and create consistent is to use > > gettimeofday clocksource resolution timestamps for files. This however > > would potentially cause a large performance hit, since each every file > > timestamp would require a possibly expensive read of the clocksource. > > Why clocksource() reading is so slow? the implementation of current > tsc clocksource ->read method is here. > > > static cycle_t read_tsc(struct clocksource *cs) > { > cycle_t ret = (cycle_t)get_cycles(); > > return ret >= clocksource_tsc.cycle_last ? > ret : clocksource_tsc.cycle_last; > } > > It mean, the difference is almost only one rdtsc. Sure, for hardware that can use the TSC clocksource, it is fairly cheap, however there are numerous systems that cannot use the TSC (or architectures that don't have a fast TSC like counter) and in those cases a read can take more then a microsecond. Even with the TSC, the multiplication required to convert to nanoseconds adds extra overhead that isn't seen when using the pre-calculated tick-granular current_kernel_time() value. It may not seem like much, but with filesystems each small delay adds up. I'm not a filesystems guy, and maybe there are some filesystems that really want very fine-grained timestamps. If so they can consider switching from using current_kernel_time() to getnstimeofday(). But due to the likely performance impact, its not something I'd suggest doing. thanks -john ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies 2010-07-15 2:46 ` john stultz @ 2010-07-15 4:41 ` KOSAKI Motohiro 2010-07-15 19:30 ` john stultz 0 siblings, 1 reply; 35+ messages in thread From: KOSAKI Motohiro @ 2010-07-15 4:41 UTC (permalink / raw) To: john stultz Cc: kosaki.motohiro, LKML, Jiri Olsa, Thomas Gleixner, Oleg Nesterov > On Thu, 2010-07-15 at 10:51 +0900, KOSAKI Motohiro wrote: > > > On Wed, 2010-07-14 at 11:40 +0900, KOSAKI Motohiro wrote: > > > > Hi > > > > > > > > > Due to vtime calling vgettimeofday(), its possible that an application > > > > > could call time();create("stuff",O_RDRW); only to see the file's > > > > > creation timestamp to be before the value returned by time. > > > > > > > > Just dumb question. > > > > > > > > Almost application are using gettimeofday() instead time(). It mean > > > > your fix don't solve almost application. > > > > > > Correct, filesystem timestamps and gettimeofday can still seem > > > inconsistently ordered. But that is expected. > > > > > > Because of granularity differences (one interface is only tick > > > resolution, the other is clocksource resolution), we can't interleave > > > the two interfaces (time and gettimeofday, respectively) and expect to > > > get ordered results. > > > > hmmm... > > Yes, times() vs gettimeofday() mekes no sense. nobody want this. but > > I don't understand why we can ignore gettimeofday() vs file-tiemstamp. > > > So, just to be clear, this discussion is really around the question of > "Why don't filesystems use a clocksource-granular (ie: getnstimeofday()) > timestamps instead of tick-granular (ie current_kernel_time()) > timestamps." > > However, this is *not* what the patch that started this thread was > about. In the patch I'm simply fixing an inconsistency in the vtime > interface, where it does not align with what the syscall-time interface > provides. > > The issue was noticed via inconsistencies with filesystem timestamps, > but the patch does not change anything to do with filesystem timestamp > behavior. Ah, I see. This patch is unrelated to filesystem timestamp. It fix inconsistency vsyscall with syscall. I agree that it should be fixed. So yes, other parts of my mail is a bit offtopic. > > > This is why the fix I'm proposing is important: Filesystem timestamps > > > have always been tick granular, so when vtime() was made clocksource > > > granular (by using vgettime internally) we broke the historic > > > expectation that the time() interface could be interleaved with > > > filesystem operations. > > > > > > Side note: For full nanosecond resolution of the tick-granular > > > timestamps, check out the clock_gettime(CLOCK_REALTIME_COARSE, ...) > > > interface. > > > > > > > > > > So, Why can't we fix vgettimeofday() vs create() inconsistency? > > > > This is just question, I don't intend to disagree you. > > > > > > The only way to make gettimeofday and create consistent is to use > > > gettimeofday clocksource resolution timestamps for files. This however > > > would potentially cause a large performance hit, since each every file > > > timestamp would require a possibly expensive read of the clocksource. > > > > Why clocksource() reading is so slow? the implementation of current > > tsc clocksource ->read method is here. > > > > > > static cycle_t read_tsc(struct clocksource *cs) > > { > > cycle_t ret = (cycle_t)get_cycles(); > > > > return ret >= clocksource_tsc.cycle_last ? > > ret : clocksource_tsc.cycle_last; > > } > > > > It mean, the difference is almost only one rdtsc. > > Sure, for hardware that can use the TSC clocksource, it is fairly cheap, > however there are numerous systems that cannot use the TSC (or > architectures that don't have a fast TSC like counter) and in those > cases a read can take more then a microsecond. I'm not timekeeping expert. but my first impression is, if clocksource->read need more than a microsecond, it's really problematic. ->read of such clocksource should always return 0 instead honestly reading h/w counter. > > Even with the TSC, the multiplication required to convert to nanoseconds > adds extra overhead that isn't seen when using the pre-calculated > tick-granular current_kernel_time() value. > > It may not seem like much, but with filesystems each small delay adds > up. > > I'm not a filesystems guy, and maybe there are some filesystems that > really want very fine-grained timestamps. If so they can consider > switching from using current_kernel_time() to getnstimeofday(). But due > to the likely performance impact, its not something I'd suggest doing. Again, I'm not against you. I only would like to hear what you propose. because I'm not sure rough granularity time() vsyscall really makes userland happy. because (again) as far as iknow, alomsot applications don't use time(). So, I worry about more big issue remained. ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies 2010-07-15 4:41 ` KOSAKI Motohiro @ 2010-07-15 19:30 ` john stultz 0 siblings, 0 replies; 35+ messages in thread From: john stultz @ 2010-07-15 19:30 UTC (permalink / raw) To: KOSAKI Motohiro; +Cc: LKML, Jiri Olsa, Thomas Gleixner, Oleg Nesterov On Thu, 2010-07-15 at 13:41 +0900, KOSAKI Motohiro wrote: > > On Thu, 2010-07-15 at 10:51 +0900, KOSAKI Motohiro wrote: > > > > On Wed, 2010-07-14 at 11:40 +0900, KOSAKI Motohiro wrote: > > > > > Hi > > > > > > > > > > > Due to vtime calling vgettimeofday(), its possible that an application > > > > > > could call time();create("stuff",O_RDRW); only to see the file's > > > > > > creation timestamp to be before the value returned by time. > > > > > > > > > > Just dumb question. > > > > > > > > > > Almost application are using gettimeofday() instead time(). It mean > > > > > your fix don't solve almost application. > > > > > > > > Correct, filesystem timestamps and gettimeofday can still seem > > > > inconsistently ordered. But that is expected. > > > > > > > > Because of granularity differences (one interface is only tick > > > > resolution, the other is clocksource resolution), we can't interleave > > > > the two interfaces (time and gettimeofday, respectively) and expect to > > > > get ordered results. > > > > > > hmmm... > > > Yes, times() vs gettimeofday() mekes no sense. nobody want this. but > > > I don't understand why we can ignore gettimeofday() vs file-tiemstamp. > > > > > > So, just to be clear, this discussion is really around the question of > > "Why don't filesystems use a clocksource-granular (ie: getnstimeofday()) > > timestamps instead of tick-granular (ie current_kernel_time()) > > timestamps." > > > > However, this is *not* what the patch that started this thread was > > about. In the patch I'm simply fixing an inconsistency in the vtime > > interface, where it does not align with what the syscall-time interface > > provides. > > > > The issue was noticed via inconsistencies with filesystem timestamps, > > but the patch does not change anything to do with filesystem timestamp > > behavior. > > Ah, I see. This patch is unrelated to filesystem timestamp. It fix inconsistency > vsyscall with syscall. > > I agree that it should be fixed. So yes, other parts of my mail is a bit offtopic. > > > > > > This is why the fix I'm proposing is important: Filesystem timestamps > > > > have always been tick granular, so when vtime() was made clocksource > > > > granular (by using vgettime internally) we broke the historic > > > > expectation that the time() interface could be interleaved with > > > > filesystem operations. > > > > > > > > Side note: For full nanosecond resolution of the tick-granular > > > > timestamps, check out the clock_gettime(CLOCK_REALTIME_COARSE, ...) > > > > interface. > > > > > > > > > > > > > So, Why can't we fix vgettimeofday() vs create() inconsistency? > > > > > This is just question, I don't intend to disagree you. > > > > > > > > The only way to make gettimeofday and create consistent is to use > > > > gettimeofday clocksource resolution timestamps for files. This however > > > > would potentially cause a large performance hit, since each every file > > > > timestamp would require a possibly expensive read of the clocksource. > > > > > > Why clocksource() reading is so slow? the implementation of current > > > tsc clocksource ->read method is here. > > > > > > > > > static cycle_t read_tsc(struct clocksource *cs) > > > { > > > cycle_t ret = (cycle_t)get_cycles(); > > > > > > return ret >= clocksource_tsc.cycle_last ? > > > ret : clocksource_tsc.cycle_last; > > > } > > > > > > It mean, the difference is almost only one rdtsc. > > > > Sure, for hardware that can use the TSC clocksource, it is fairly cheap, > > however there are numerous systems that cannot use the TSC (or > > architectures that don't have a fast TSC like counter) and in those > > cases a read can take more then a microsecond. > > I'm not timekeeping expert. but my first impression is, if clocksource->read > need more than a microsecond, it's really problematic. ->read of such clocksource > should always return 0 instead honestly reading h/w counter. Sadly there is quite a lot of x86 hardware that cannot use the TSC. So the only alternative is the HPET (~0.8us) or ACPI PM (~1.2us). If the clocksource->read() function returned 0 on those systems, then gettimeofday would return only tick-granular time (again, which is what CLOCK_REALTIME_COARSE already provides). That said, Ingo had an optimization patch to do something quite similar, giving up resolution for speed. And now the CLOCK_REALTIME_COARSE code is there it might be even easier to implement, but its not something we can enable by default, as inter-tick resolution is need in many cases. And yes, ideally every system would have a fast TSC like counter that was accurate and reliable, and this would be less of an issue, but we have to work with the hardware that is out there. > > Even with the TSC, the multiplication required to convert to nanoseconds > > adds extra overhead that isn't seen when using the pre-calculated > > tick-granular current_kernel_time() value. > > > > It may not seem like much, but with filesystems each small delay adds > > up. > > > > I'm not a filesystems guy, and maybe there are some filesystems that > > really want very fine-grained timestamps. If so they can consider > > switching from using current_kernel_time() to getnstimeofday(). But due > > to the likely performance impact, its not something I'd suggest doing. > > Again, I'm not against you. I only would like to hear what you propose. because > I'm not sure rough granularity time() vsyscall really makes userland happy. > because (again) as far as iknow, alomsot applications don't use time(). Since I assume the developers who implemented the filesystem have considered this trade off and made a choice. I honestly don't have much to propose here. :) I think if you feel strongly that filesystems should use clocksource-granular instead of tick-granular timestamps, you might try to bring it up on ext4 devel list or even generate a patch and try it out yourself (I've provided a trivial starting point for you below - but its likely a real solution will be a bit more complex). Good luck! thanks -john diff --git a/kernel/time.c b/kernel/time.c index 848b1c2..ce10dae 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -227,7 +227,8 @@ SYSCALL_DEFINE1(adjtimex, struct timex __user *, txc_p) */ struct timespec current_fs_time(struct super_block *sb) { - struct timespec now = current_kernel_time(); + struct timespec now; + getnstimeofday(&now); return timespec_trunc(now, sb->s_time_gran); } EXPORT_SYMBOL(current_fs_time); ^ permalink raw reply related [flat|nested] 35+ messages in thread
* Re: [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies 2010-07-15 1:51 ` KOSAKI Motohiro 2010-07-15 2:46 ` john stultz @ 2010-07-15 2:51 ` john stultz 2010-07-15 4:41 ` KOSAKI Motohiro 1 sibling, 1 reply; 35+ messages in thread From: john stultz @ 2010-07-15 2:51 UTC (permalink / raw) To: KOSAKI Motohiro; +Cc: LKML, Jiri Olsa, Thomas Gleixner, Oleg Nesterov On Thu, 2010-07-15 at 10:51 +0900, KOSAKI Motohiro wrote: > > On Wed, 2010-07-14 at 11:40 +0900, KOSAKI Motohiro wrote: > > > Hi > > > > > > > Due to vtime calling vgettimeofday(), its possible that an application > > > > could call time();create("stuff",O_RDRW); only to see the file's > > > > creation timestamp to be before the value returned by time. > > > > > > Just dumb question. > > > > > > Almost application are using gettimeofday() instead time(). It mean > > > your fix don't solve almost application. > > > > Correct, filesystem timestamps and gettimeofday can still seem > > inconsistently ordered. But that is expected. > > > > Because of granularity differences (one interface is only tick > > resolution, the other is clocksource resolution), we can't interleave > > the two interfaces (time and gettimeofday, respectively) and expect to > > get ordered results. > > hmmm... > Yes, times() vs gettimeofday() mekes no sense. nobody want this. but > I don't understand why we can ignore gettimeofday() vs file-tiemstamp. Oh.. and another bit worth mentioning again: clock_gettime(CLOCK_REALTIME_COARSE, ...) provides tick-granular output that should be able to be correctly interleaved with filesystem timestmaps. So if there's an application that is using gettimeofday() for logging and having problems trying to map the log timestmaps with filesystem timestamps, they can use clock_gettime(CLOCK_REALTIME_COARSE,...) to do so correctly. thanks -john ^ permalink raw reply [flat|nested] 35+ messages in thread
* Re: [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies 2010-07-15 2:51 ` john stultz @ 2010-07-15 4:41 ` KOSAKI Motohiro 0 siblings, 0 replies; 35+ messages in thread From: KOSAKI Motohiro @ 2010-07-15 4:41 UTC (permalink / raw) To: john stultz Cc: kosaki.motohiro, LKML, Jiri Olsa, Thomas Gleixner, Oleg Nesterov > On Thu, 2010-07-15 at 10:51 +0900, KOSAKI Motohiro wrote: > > > On Wed, 2010-07-14 at 11:40 +0900, KOSAKI Motohiro wrote: > > > > Hi > > > > > > > > > Due to vtime calling vgettimeofday(), its possible that an application > > > > > could call time();create("stuff",O_RDRW); only to see the file's > > > > > creation timestamp to be before the value returned by time. > > > > > > > > Just dumb question. > > > > > > > > Almost application are using gettimeofday() instead time(). It mean > > > > your fix don't solve almost application. > > > > > > Correct, filesystem timestamps and gettimeofday can still seem > > > inconsistently ordered. But that is expected. > > > > > > Because of granularity differences (one interface is only tick > > > resolution, the other is clocksource resolution), we can't interleave > > > the two interfaces (time and gettimeofday, respectively) and expect to > > > get ordered results. > > > > hmmm... > > Yes, times() vs gettimeofday() mekes no sense. nobody want this. but > > I don't understand why we can ignore gettimeofday() vs file-tiemstamp. > > Oh.. and another bit worth mentioning again: > clock_gettime(CLOCK_REALTIME_COARSE, ...) provides tick-granular output > that should be able to be correctly interleaved with filesystem > timestmaps. > > So if there's an application that is using gettimeofday() for logging > and having problems trying to map the log timestmaps with filesystem > timestamps, they can use clock_gettime(CLOCK_REALTIME_COARSE,...) to do > so correctly. Correct. but I disagree few bit . 1) application naturally assume time don't makes interleaving. so almost all applications don't have such care. 2) tick-granular fs timestamp is only current implementaion. perhaps we will change it later. so, applications don't want to assume fs timestamp granularity is equal to CLOCK_REALTIME_COARSE. ^ permalink raw reply [flat|nested] 35+ messages in thread
* [tip:timers/clocksource] x86: Fix vtime/file timestamp inconsistencies 2010-07-14 0:56 ` [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies John Stultz 2010-07-14 0:56 ` [PATCH 02/11] Implement timespec_add John Stultz 2010-07-14 2:40 ` [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies KOSAKI Motohiro @ 2010-07-27 10:45 ` tip-bot for John Stultz 2 siblings, 0 replies; 35+ messages in thread From: tip-bot for John Stultz @ 2010-07-27 10:45 UTC (permalink / raw) To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, johnstul, oleg, tglx, jolsa Commit-ID: 8c73626ab28527b7eb7f3061c027fbfe530c488c Gitweb: http://git.kernel.org/tip/8c73626ab28527b7eb7f3061c027fbfe530c488c Author: John Stultz <johnstul@us.ibm.com> AuthorDate: Tue, 13 Jul 2010 17:56:18 -0700 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Tue, 27 Jul 2010 12:40:53 +0200 x86: Fix vtime/file timestamp inconsistencies Due to vtime calling vgettimeofday(), its possible that an application could call time();create("stuff",O_RDRW); only to see the file's creation timestamp to be before the value returned by time. A similar way to reproduce the issue is to compare the vsyscall time() with the syscall time(), and observe ordering issues. The modified test case from Oleg Nesterov below can illustrate this: int main(void) { time_t sec1,sec2; do { sec1 = time(&sec2); sec2 = syscall(__NR_time, NULL); } while (sec1 <= sec2); printf("vtime: %d.000000\n", sec1); printf("time: %d.000000\n", sec2); return 0; } The proper fix is to make vtime use the same time value as current_kernel_time() (which is exported via update_vsyscall) instead of vgettime(). Thanks to Jiri Olsa for bringing up the issue and catching bugs in earlier verisons of this fix. Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> LKML-Reference: <1279068988-21864-2-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- arch/x86/kernel/vsyscall_64.c | 11 ++++++++--- 1 files changed, 8 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index 1c0c6ab..dce0c3c 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -169,13 +169,18 @@ int __vsyscall(0) vgettimeofday(struct timeval * tv, struct timezone * tz) * unlikely */ time_t __vsyscall(1) vtime(time_t *t) { - struct timeval tv; + unsigned seq; time_t result; if (unlikely(!__vsyscall_gtod_data.sysctl_enabled)) return time_syscall(t); - vgettimeofday(&tv, NULL); - result = tv.tv_sec; + do { + seq = read_seqbegin(&__vsyscall_gtod_data.lock); + + result = __vsyscall_gtod_data.wall_time_sec; + + } while (read_seqretry(&__vsyscall_gtod_data.lock, seq)); + if (t) *t = result; return result; ^ permalink raw reply related [flat|nested] 35+ messages in thread
end of thread, other threads:[~2010-07-28 1:33 UTC | newest] Thread overview: 35+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2010-07-14 0:56 [PATCH 00/11] -tip Timekeeping changes for 2.6.36 John Stultz 2010-07-14 0:56 ` [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies John Stultz 2010-07-14 0:56 ` [PATCH 02/11] Implement timespec_add John Stultz 2010-07-14 0:56 ` [PATCH 03/11] time: Kill off CONFIG_GENERIC_TIME John Stultz 2010-07-14 0:56 ` [PATCH 04/11] powerpc: Simplify update_vsyscall John Stultz 2010-07-14 0:56 ` [PATCH 05/11] powerpc: Cleanup xtime usage John Stultz 2010-07-14 0:56 ` [PATCH 06/11] Fix update_vsyscall to provide wall_to_monotonic offset John Stultz 2010-07-14 0:56 ` [PATCH 07/11] Convert um to use read_persistent_clock John Stultz 2010-07-14 0:56 ` [PATCH 08/11] Cleanup hrtimer.c's direct access to wall_to_monotonic John Stultz 2010-07-14 0:56 ` [PATCH 09/11] Make xtime and wall_to_monotonic static John Stultz 2010-07-14 0:56 ` [PATCH 10/11] Convert common x86 clocksources to use clocksource_register_hz/khz John Stultz 2010-07-14 0:56 ` [PATCH 11/11] Add __clocksource_updatefreq_hz/khz methods John Stultz 2010-07-27 10:49 ` [tip:timers/clocksource] clocksource: " tip-bot for John Stultz 2010-07-27 10:48 ` [tip:timers/clocksource] x86: Convert common clocksources to use clocksource_register_hz/khz tip-bot for John Stultz 2010-07-27 10:48 ` [tip:timers/clocksource] timekeeping: Make xtime and wall_to_monotonic static tip-bot for John Stultz 2010-07-27 10:48 ` [tip:timers/clocksource] hrtimer: Cleanup direct access to wall_to_monotonic tip-bot for John Stultz 2010-07-27 10:47 ` [tip:timers/clocksource] um: Convert to use read_persistent_clock tip-bot for John Stultz 2010-07-27 10:47 ` [tip:timers/clocksource] timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset tip-bot for John Stultz 2010-07-27 10:47 ` [tip:timers/clocksource] powerpc: Cleanup xtime usage tip-bot for John Stultz 2010-07-27 10:46 ` [tip:timers/clocksource] powerpc: Simplify update_vsyscall tip-bot for John Stultz 2010-07-27 23:41 ` [PATCH 04/11] " Paul Mackerras 2010-07-27 23:41 ` Paul Mackerras 2010-07-28 1:33 ` john stultz 2010-07-28 1:33 ` john stultz 2010-07-27 10:46 ` [tip:timers/clocksource] time: Kill off CONFIG_GENERIC_TIME tip-bot for John Stultz 2010-07-27 10:46 ` [tip:timers/clocksource] time: Implement timespec_add tip-bot for John Stultz 2010-07-14 2:40 ` [PATCH 01/11] x86: Fix vtime/file timestamp inconsistencies KOSAKI Motohiro 2010-07-14 16:19 ` john stultz 2010-07-15 1:51 ` KOSAKI Motohiro 2010-07-15 2:46 ` john stultz 2010-07-15 4:41 ` KOSAKI Motohiro 2010-07-15 19:30 ` john stultz 2010-07-15 2:51 ` john stultz 2010-07-15 4:41 ` KOSAKI Motohiro 2010-07-27 10:45 ` [tip:timers/clocksource] " tip-bot for John Stultz
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