* [PATCH RT 0/8] [ANNOUNCE] 3.2.22-rt35-rc1 stable review
@ 2012-07-12 23:18 Steven Rostedt
2012-07-12 23:18 ` [PATCH RT 1/8] Latency histogramms: Cope with backwards running local trace clock Steven Rostedt
` (7 more replies)
0 siblings, 8 replies; 9+ messages in thread
From: Steven Rostedt @ 2012-07-12 23:18 UTC (permalink / raw)
To: linux-kernel, linux-rt-users; +Cc: Thomas Gleixner, Carsten Emde, John Kacur
Dear RT Folks,
This is the RT stable review cycle of patch 3.2.22-rt35-rc1.
Please scream at me if I messed something up. Please test the patches too.
The -rc release will be uploaded to kernel.org and will be deleted when
the final release is out. This is just a review release (or release candidate).
The pre-releases will not be pushed to the git repository, only the
final release is.
If all goes well, this patch will be converted to the next main release
on 7/16/2012.
Enjoy,
-- Steve
To build 3.2.22-rt35-rc1 directly, the following patches should be applied:
http://www.kernel.org/pub/linux/kernel/v3.x/linux-3.2.tar.xz
http://www.kernel.org/pub/linux/kernel/v3.x/patch-3.2.22.xz
http://www.kernel.org/pub/linux/kernel/projects/rt/3.2/patch-3.2.22-rt35-rc1.patch.xz
You can also build from 3.2.22-rt34 by applying the incremental patch:
http://www.kernel.org/pub/linux/kernel/projects/rt/3.2/incr/patch-3.2.22-rt34-rt35-rc1.patch.xz
Changes from 3.2.22-rt34:
---
Carsten Emde (4):
Latency histogramms: Cope with backwards running local trace clock
Latency histograms: Adjust timer, if already elapsed when programmed
Disable RT_GROUP_SCHED in PREEMPT_RT_FULL
Latency histograms: Detect another yet overlooked sharedprio condition
Mike Galbraith (1):
fs, jbd: pull your plug when waiting for space
Steven Rostedt (1):
Linux 3.2.22-rt35-rc1
Thomas Gleixner (1):
slab: Prevent local lock deadlock
Yong Zhang (1):
perf: Make swevent hrtimer run in irq instead of softirq
----
fs/jbd/checkpoint.c | 2 ++
include/linux/hrtimer.h | 3 ++
include/linux/sched.h | 2 +-
init/Kconfig | 1 +
kernel/events/core.c | 1 +
kernel/hrtimer.c | 16 ++++++++--
kernel/trace/latency_hist.c | 74 +++++++++++++++++++++++--------------------
localversion-rt | 2 +-
mm/slab.c | 26 ++++++++++++---
9 files changed, 85 insertions(+), 42 deletions(-)
^ permalink raw reply [flat|nested] 9+ messages in thread* [PATCH RT 1/8] Latency histogramms: Cope with backwards running local trace clock 2012-07-12 23:18 [PATCH RT 0/8] [ANNOUNCE] 3.2.22-rt35-rc1 stable review Steven Rostedt @ 2012-07-12 23:18 ` Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 2/8] Latency histograms: Adjust timer, if already elapsed when programmed Steven Rostedt ` (6 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: Steven Rostedt @ 2012-07-12 23:18 UTC (permalink / raw) To: linux-kernel, linux-rt-users; +Cc: Thomas Gleixner, Carsten Emde, John Kacur [-- Attachment #1: 0001-Latency-histogramms-Cope-with-backwards-running-loca.patch --] [-- Type: text/plain, Size: 9412 bytes --] From: Carsten Emde <C.Emde@osadl.org> Thanks to the wonders of modern technology, the local trace clock can now run backwards. Since this never happened before, the time difference between now and somewhat earlier was expected to never become negative and, thus, stored in an unsigned integer variable. Nowadays, we need a signed integer to ensure that the value is stored as underflow in the related histogram. (In cases where this is not a misfunction, bipolar histograms can be used.) This patch takes care that all latency variables are represented as signed integers and negative numbers are considered as histogram underflows. In one of the misbehaving processors switching to global clock solved the problem: echo global >/sys/kernel/debug/tracing/trace_clock Signed-off-by: Carsten Emde <C.Emde@osadl.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> --- include/linux/sched.h | 2 +- kernel/trace/latency_hist.c | 71 ++++++++++++++++++++++--------------------- 2 files changed, 38 insertions(+), 35 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 1f6b11a..0174e3a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1585,7 +1585,7 @@ struct task_struct { #ifdef CONFIG_WAKEUP_LATENCY_HIST u64 preempt_timestamp_hist; #ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST - unsigned long timer_offset; + long timer_offset; #endif #endif #endif /* CONFIG_TRACING */ diff --git a/kernel/trace/latency_hist.c b/kernel/trace/latency_hist.c index 9d49fcb..d514eef 100644 --- a/kernel/trace/latency_hist.c +++ b/kernel/trace/latency_hist.c @@ -27,6 +27,8 @@ #include "trace.h" #include <trace/events/sched.h> +#define NSECS_PER_USECS 1000L + #define CREATE_TRACE_POINTS #include <trace/events/hist.h> @@ -46,11 +48,11 @@ enum { struct hist_data { atomic_t hist_mode; /* 0 log, 1 don't log */ long offset; /* set it to MAX_ENTRY_NUM/2 for a bipolar scale */ - unsigned long min_lat; - unsigned long max_lat; + long min_lat; + long max_lat; unsigned long long below_hist_bound_samples; unsigned long long above_hist_bound_samples; - unsigned long long accumulate_lat; + long long accumulate_lat; unsigned long long total_samples; unsigned long long hist_array[MAX_ENTRY_NUM]; }; @@ -152,8 +154,8 @@ static struct enable_data timerandwakeup_enabled_data = { static DEFINE_PER_CPU(struct maxlatproc_data, timerandwakeup_maxlatproc); #endif -void notrace latency_hist(int latency_type, int cpu, unsigned long latency, - unsigned long timeroffset, cycle_t stop, +void notrace latency_hist(int latency_type, int cpu, long latency, + long timeroffset, cycle_t stop, struct task_struct *p) { struct hist_data *my_hist; @@ -224,7 +226,7 @@ void notrace latency_hist(int latency_type, int cpu, unsigned long latency, my_hist->hist_array[latency]++; if (unlikely(latency > my_hist->max_lat || - my_hist->min_lat == ULONG_MAX)) { + my_hist->min_lat == LONG_MAX)) { #if defined(CONFIG_WAKEUP_LATENCY_HIST) || \ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST) if (latency_type == WAKEUP_LATENCY || @@ -263,15 +265,14 @@ static void *l_start(struct seq_file *m, loff_t *pos) atomic_dec(&my_hist->hist_mode); if (likely(my_hist->total_samples)) { - unsigned long avg = (unsigned long) - div64_u64(my_hist->accumulate_lat, + long avg = (long) div64_s64(my_hist->accumulate_lat, my_hist->total_samples); snprintf(minstr, sizeof(minstr), "%ld", - (long) my_hist->min_lat - my_hist->offset); + my_hist->min_lat - my_hist->offset); snprintf(avgstr, sizeof(avgstr), "%ld", - (long) avg - my_hist->offset); + avg - my_hist->offset); snprintf(maxstr, sizeof(maxstr), "%ld", - (long) my_hist->max_lat - my_hist->offset); + my_hist->max_lat - my_hist->offset); } else { strcpy(minstr, "<undef>"); strcpy(avgstr, minstr); @@ -376,10 +377,10 @@ static void hist_reset(struct hist_data *hist) memset(hist->hist_array, 0, sizeof(hist->hist_array)); hist->below_hist_bound_samples = 0ULL; hist->above_hist_bound_samples = 0ULL; - hist->min_lat = ULONG_MAX; - hist->max_lat = 0UL; + hist->min_lat = LONG_MAX; + hist->max_lat = LONG_MIN; hist->total_samples = 0ULL; - hist->accumulate_lat = 0ULL; + hist->accumulate_lat = 0LL; atomic_inc(&hist->hist_mode); } @@ -790,9 +791,9 @@ static notrace void probe_preemptirqsoff_hist(void *v, int reason, stop = ftrace_now(cpu); time_set++; - if (start && stop >= start) { - unsigned long latency = - nsecs_to_usecs(stop - start); + if (start) { + long latency = ((long) (stop - start)) / + NSECS_PER_USECS; latency_hist(IRQSOFF_LATENCY, cpu, latency, 0, stop, NULL); @@ -808,9 +809,9 @@ static notrace void probe_preemptirqsoff_hist(void *v, int reason, if (!(time_set++)) stop = ftrace_now(cpu); - if (start && stop >= start) { - unsigned long latency = - nsecs_to_usecs(stop - start); + if (start) { + long latency = ((long) (stop - start)) / + NSECS_PER_USECS; latency_hist(PREEMPTOFF_LATENCY, cpu, latency, 0, stop, NULL); @@ -827,9 +828,10 @@ static notrace void probe_preemptirqsoff_hist(void *v, int reason, if (!time_set) stop = ftrace_now(cpu); - if (start && stop >= start) { - unsigned long latency = - nsecs_to_usecs(stop - start); + if (start) { + long latency = ((long) (stop - start)) / + NSECS_PER_USECS; + latency_hist(PREEMPTIRQSOFF_LATENCY, cpu, latency, 0, stop, NULL); } @@ -908,7 +910,7 @@ static notrace void probe_wakeup_latency_hist_stop(void *v, { unsigned long flags; int cpu = task_cpu(next); - unsigned long latency; + long latency; cycle_t stop; struct task_struct *cpu_wakeup_task; @@ -939,7 +941,8 @@ static notrace void probe_wakeup_latency_hist_stop(void *v, */ stop = ftrace_now(raw_smp_processor_id()); - latency = nsecs_to_usecs(stop - next->preempt_timestamp_hist); + latency = ((long) (stop - next->preempt_timestamp_hist)) / + NSECS_PER_USECS; if (per_cpu(wakeup_sharedprio, cpu)) { latency_hist(WAKEUP_LATENCY_SHAREDPRIO, cpu, latency, 0, stop, @@ -975,7 +978,7 @@ static notrace void probe_hrtimer_interrupt(void *v, int cpu, (task->prio < curr->prio || (task->prio == curr->prio && !cpumask_test_cpu(cpu, &task->cpus_allowed)))) { - unsigned long latency; + long latency; cycle_t now; if (missed_timer_offsets_pid) { @@ -985,7 +988,7 @@ static notrace void probe_hrtimer_interrupt(void *v, int cpu, } now = ftrace_now(cpu); - latency = (unsigned long) div_s64(-latency_ns, 1000); + latency = (long) div_s64(-latency_ns, NSECS_PER_USECS); latency_hist(MISSED_TIMER_OFFSETS, cpu, latency, latency, now, task); #ifdef CONFIG_WAKEUP_LATENCY_HIST @@ -1026,7 +1029,7 @@ static __init int latency_hist_init(void) &per_cpu(irqsoff_hist, i), &latency_hist_fops); my_hist = &per_cpu(irqsoff_hist, i); atomic_set(&my_hist->hist_mode, 1); - my_hist->min_lat = 0xFFFFFFFFUL; + my_hist->min_lat = LONG_MAX; } entry = debugfs_create_file("reset", 0644, dentry, (void *)IRQSOFF_LATENCY, &latency_hist_reset_fops); @@ -1041,7 +1044,7 @@ static __init int latency_hist_init(void) &per_cpu(preemptoff_hist, i), &latency_hist_fops); my_hist = &per_cpu(preemptoff_hist, i); atomic_set(&my_hist->hist_mode, 1); - my_hist->min_lat = 0xFFFFFFFFUL; + my_hist->min_lat = LONG_MAX; } entry = debugfs_create_file("reset", 0644, dentry, (void *)PREEMPTOFF_LATENCY, &latency_hist_reset_fops); @@ -1056,7 +1059,7 @@ static __init int latency_hist_init(void) &per_cpu(preemptirqsoff_hist, i), &latency_hist_fops); my_hist = &per_cpu(preemptirqsoff_hist, i); atomic_set(&my_hist->hist_mode, 1); - my_hist->min_lat = 0xFFFFFFFFUL; + my_hist->min_lat = LONG_MAX; } entry = debugfs_create_file("reset", 0644, dentry, (void *)PREEMPTIRQSOFF_LATENCY, &latency_hist_reset_fops); @@ -1081,14 +1084,14 @@ static __init int latency_hist_init(void) &latency_hist_fops); my_hist = &per_cpu(wakeup_latency_hist, i); atomic_set(&my_hist->hist_mode, 1); - my_hist->min_lat = 0xFFFFFFFFUL; + my_hist->min_lat = LONG_MAX; entry = debugfs_create_file(name, 0444, dentry_sharedprio, &per_cpu(wakeup_latency_hist_sharedprio, i), &latency_hist_fops); my_hist = &per_cpu(wakeup_latency_hist_sharedprio, i); atomic_set(&my_hist->hist_mode, 1); - my_hist->min_lat = 0xFFFFFFFFUL; + my_hist->min_lat = LONG_MAX; sprintf(name, cpufmt_maxlatproc, i); @@ -1122,7 +1125,7 @@ static __init int latency_hist_init(void) &per_cpu(missed_timer_offsets, i), &latency_hist_fops); my_hist = &per_cpu(missed_timer_offsets, i); atomic_set(&my_hist->hist_mode, 1); - my_hist->min_lat = 0xFFFFFFFFUL; + my_hist->min_lat = LONG_MAX; sprintf(name, cpufmt_maxlatproc, i); mp = &per_cpu(missed_timer_offsets_maxlatproc, i); @@ -1150,7 +1153,7 @@ static __init int latency_hist_init(void) &latency_hist_fops); my_hist = &per_cpu(timerandwakeup_latency_hist, i); atomic_set(&my_hist->hist_mode, 1); - my_hist->min_lat = 0xFFFFFFFFUL; + my_hist->min_lat = LONG_MAX; sprintf(name, cpufmt_maxlatproc, i); mp = &per_cpu(timerandwakeup_maxlatproc, i); -- 1.7.10.4 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH RT 2/8] Latency histograms: Adjust timer, if already elapsed when programmed 2012-07-12 23:18 [PATCH RT 0/8] [ANNOUNCE] 3.2.22-rt35-rc1 stable review Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 1/8] Latency histogramms: Cope with backwards running local trace clock Steven Rostedt @ 2012-07-12 23:18 ` Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 3/8] Disable RT_GROUP_SCHED in PREEMPT_RT_FULL Steven Rostedt ` (5 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: Steven Rostedt @ 2012-07-12 23:18 UTC (permalink / raw) To: linux-kernel, linux-rt-users; +Cc: Thomas Gleixner, Carsten Emde, John Kacur [-- Attachment #1: 0002-Latency-histograms-Adjust-timer-if-already-elapsed-w.patch --] [-- Type: text/plain, Size: 2129 bytes --] From: Carsten Emde <C.Emde@osadl.org> Nothing prevents a programmer from calling clock_nanosleep() with an already elapsed wakeup time in absolute time mode or with a too small delay in relative time mode. Such timers cannot wake up in time and, thus, should be corrected when entered into the missed timers latency histogram (CONFIG_MISSED_TIMERS_HIST). This patch marks such timers and uses a corrected expiration time. Signed-off-by: Carsten Emde <C.Emde@osadl.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> --- include/linux/hrtimer.h | 3 +++ kernel/hrtimer.c | 16 ++++++++++++++-- 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 0e37086..7408760 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -113,6 +113,9 @@ struct hrtimer { unsigned long state; struct list_head cb_entry; int irqsafe; +#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST + ktime_t praecox; +#endif #ifdef CONFIG_TIMER_STATS int start_pid; void *start_site; diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 3991464..a080e62 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1021,6 +1021,17 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, #endif } +#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST + { + ktime_t now = new_base->get_time(); + + if (ktime_to_ns(tim) < ktime_to_ns(now)) + timer->praecox = now; + else + timer->praecox = ktime_set(0, 0); + } +#endif + hrtimer_set_expires_range_ns(timer, tim, delta_ns); timer_stats_hrtimer_set_start_info(timer); @@ -1458,8 +1469,9 @@ retry: timer = container_of(node, struct hrtimer, node); trace_hrtimer_interrupt(raw_smp_processor_id(), - ktime_to_ns(ktime_sub( - hrtimer_get_expires(timer), basenow)), + ktime_to_ns(ktime_sub(ktime_to_ns(timer->praecox) ? + timer->praecox : hrtimer_get_expires(timer), + basenow)), current, timer->function == hrtimer_wakeup ? container_of(timer, struct hrtimer_sleeper, -- 1.7.10.4 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH RT 3/8] Disable RT_GROUP_SCHED in PREEMPT_RT_FULL 2012-07-12 23:18 [PATCH RT 0/8] [ANNOUNCE] 3.2.22-rt35-rc1 stable review Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 1/8] Latency histogramms: Cope with backwards running local trace clock Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 2/8] Latency histograms: Adjust timer, if already elapsed when programmed Steven Rostedt @ 2012-07-12 23:18 ` Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 4/8] Latency histograms: Detect another yet overlooked sharedprio condition Steven Rostedt ` (4 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: Steven Rostedt @ 2012-07-12 23:18 UTC (permalink / raw) To: linux-kernel, linux-rt-users; +Cc: Thomas Gleixner, Carsten Emde, John Kacur [-- Attachment #1: 0003-Disable-RT_GROUP_SCHED-in-PREEMPT_RT_FULL.patch --] [-- Type: text/plain, Size: 726 bytes --] From: Carsten Emde <C.Emde@osadl.org> Strange CPU stalls have been observed in RT when RT_GROUP_SCHED was configured. Disable it for now. Signed-off-by: Carsten Emde <C.Emde@osadl.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> --- init/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/init/Kconfig b/init/Kconfig index dbc82d0..720c182 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -731,6 +731,7 @@ config RT_GROUP_SCHED bool "Group scheduling for SCHED_RR/FIFO" depends on EXPERIMENTAL depends on CGROUP_SCHED + depends on !PREEMPT_RT_FULL default n help This feature lets you explicitly allocate real CPU bandwidth -- 1.7.10.4 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH RT 4/8] Latency histograms: Detect another yet overlooked sharedprio condition 2012-07-12 23:18 [PATCH RT 0/8] [ANNOUNCE] 3.2.22-rt35-rc1 stable review Steven Rostedt ` (2 preceding siblings ...) 2012-07-12 23:18 ` [PATCH RT 3/8] Disable RT_GROUP_SCHED in PREEMPT_RT_FULL Steven Rostedt @ 2012-07-12 23:18 ` Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 5/8] slab: Prevent local lock deadlock Steven Rostedt ` (3 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: Steven Rostedt @ 2012-07-12 23:18 UTC (permalink / raw) To: linux-kernel, linux-rt-users; +Cc: Thomas Gleixner, Carsten Emde, John Kacur [-- Attachment #1: 0004-Latency-histograms-Detect-another-yet-overlooked-sha.patch --] [-- Type: text/plain, Size: 1159 bytes --] From: Carsten Emde <C.Emde@osadl.org> While waiting for an RT process to be woken up, the previous process may go to wait and switch to another one with the same priority which then becomes current. This condition was not correctly recognized and led to erroneously high latency recordings during periods of low CPU load. This patch correctly marks such latencies as sharedprio and prevents them from being recorded as actual system latency. Signed-off-by: Carsten Emde <C.Emde@osadl.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> --- kernel/trace/latency_hist.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/trace/latency_hist.c b/kernel/trace/latency_hist.c index d514eef..6a4c869 100644 --- a/kernel/trace/latency_hist.c +++ b/kernel/trace/latency_hist.c @@ -935,6 +935,9 @@ static notrace void probe_wakeup_latency_hist_stop(void *v, goto out; } + if (current->prio == cpu_wakeup_task->prio) + per_cpu(wakeup_sharedprio, cpu) = 1; + /* * The task we are waiting for is about to be switched to. * Calculate latency and store it in histogram. -- 1.7.10.4 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH RT 5/8] slab: Prevent local lock deadlock 2012-07-12 23:18 [PATCH RT 0/8] [ANNOUNCE] 3.2.22-rt35-rc1 stable review Steven Rostedt ` (3 preceding siblings ...) 2012-07-12 23:18 ` [PATCH RT 4/8] Latency histograms: Detect another yet overlooked sharedprio condition Steven Rostedt @ 2012-07-12 23:18 ` Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 6/8] fs, jbd: pull your plug when waiting for space Steven Rostedt ` (2 subsequent siblings) 7 siblings, 0 replies; 9+ messages in thread From: Steven Rostedt @ 2012-07-12 23:18 UTC (permalink / raw) To: linux-kernel, linux-rt-users; +Cc: Thomas Gleixner, Carsten Emde, John Kacur [-- Attachment #1: 0005-slab-Prevent-local-lock-deadlock.patch --] [-- Type: text/plain, Size: 1998 bytes --] From: Thomas Gleixner <tglx@linutronix.de> On RT we avoid the cross cpu function calls and take the per cpu local locks instead. Now the code missed that taking the local lock on the cpu which runs the code must use the proper local lock functions and not a simple spin_lock(). Otherwise it deadlocks later when trying to acquire the local lock with the proper function. Reported-and-tested-by: Chris Pringle <chris.pringle@miranda.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> --- mm/slab.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index 5f0c5ef..3bef5e5 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -739,8 +739,26 @@ slab_on_each_cpu(void (*func)(void *arg, int this_cpu), void *arg) { unsigned int i; + get_cpu_light(); for_each_online_cpu(i) func(arg, i); + put_cpu_light(); +} + +static void lock_slab_on(unsigned int cpu) +{ + if (cpu == smp_processor_id()) + local_lock_irq(slab_lock); + else + local_spin_lock_irq(slab_lock, &per_cpu(slab_lock, cpu).lock); +} + +static void unlock_slab_on(unsigned int cpu) +{ + if (cpu == smp_processor_id()) + local_unlock_irq(slab_lock); + else + local_spin_unlock_irq(slab_lock, &per_cpu(slab_lock, cpu).lock); } #endif @@ -2627,10 +2645,10 @@ static void do_drain(void *arg, int cpu) { LIST_HEAD(tmp); - spin_lock_irq(&per_cpu(slab_lock, cpu).lock); + lock_slab_on(cpu); __do_drain(arg, cpu); list_splice_init(&per_cpu(slab_free_list, cpu), &tmp); - spin_unlock_irq(&per_cpu(slab_lock, cpu).lock); + unlock_slab_on(cpu); free_delayed(&tmp); } #endif @@ -4095,9 +4113,9 @@ static void do_ccupdate_local(void *info) #else static void do_ccupdate_local(void *info, int cpu) { - spin_lock_irq(&per_cpu(slab_lock, cpu).lock); + lock_slab_on(cpu); __do_ccupdate_local(info, cpu); - spin_unlock_irq(&per_cpu(slab_lock, cpu).lock); + unlock_slab_on(cpu); } #endif -- 1.7.10.4 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH RT 6/8] fs, jbd: pull your plug when waiting for space 2012-07-12 23:18 [PATCH RT 0/8] [ANNOUNCE] 3.2.22-rt35-rc1 stable review Steven Rostedt ` (4 preceding siblings ...) 2012-07-12 23:18 ` [PATCH RT 5/8] slab: Prevent local lock deadlock Steven Rostedt @ 2012-07-12 23:18 ` Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 7/8] perf: Make swevent hrtimer run in irq instead of softirq Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 8/8] Linux 3.2.22-rt35-rc1 Steven Rostedt 7 siblings, 0 replies; 9+ messages in thread From: Steven Rostedt @ 2012-07-12 23:18 UTC (permalink / raw) To: linux-kernel, linux-rt-users Cc: Thomas Gleixner, Carsten Emde, John Kacur, Mike Galbraith, Theodore Tso [-- Attachment #1: 0006-fs-jbd-pull-your-plug-when-waiting-for-space.patch --] [-- Type: text/plain, Size: 1002 bytes --] From: Mike Galbraith <mgalbraith@suse.de> With an -rt kernel, and a heavy sync IO load, tasks can jam up on journal locks without unplugging, which can lead to terminal IO starvation. Unplug and schedule when waiting for space. Signed-off-by: Mike Galbraith <mgalbraith@suse.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Theodore Tso <tytso@mit.edu> Link: http://lkml.kernel.org/r/1341812414.7370.73.camel@marge.simpson.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> --- fs/jbd/checkpoint.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/jbd/checkpoint.c b/fs/jbd/checkpoint.c index 5c93ffc..ddbd223 100644 --- a/fs/jbd/checkpoint.c +++ b/fs/jbd/checkpoint.c @@ -129,6 +129,8 @@ void __log_wait_for_space(journal_t *journal) if (journal->j_flags & JFS_ABORT) return; spin_unlock(&journal->j_state_lock); + if (current->plug) + io_schedule(); mutex_lock(&journal->j_checkpoint_mutex); /* -- 1.7.10.4 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH RT 7/8] perf: Make swevent hrtimer run in irq instead of softirq 2012-07-12 23:18 [PATCH RT 0/8] [ANNOUNCE] 3.2.22-rt35-rc1 stable review Steven Rostedt ` (5 preceding siblings ...) 2012-07-12 23:18 ` [PATCH RT 6/8] fs, jbd: pull your plug when waiting for space Steven Rostedt @ 2012-07-12 23:18 ` Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 8/8] Linux 3.2.22-rt35-rc1 Steven Rostedt 7 siblings, 0 replies; 9+ messages in thread From: Steven Rostedt @ 2012-07-12 23:18 UTC (permalink / raw) To: linux-kernel, linux-rt-users Cc: Thomas Gleixner, Carsten Emde, John Kacur, Yong Zhang, Peter Zijlstra [-- Attachment #1: 0007-perf-Make-swevent-hrtimer-run-in-irq-instead-of-soft.patch --] [-- Type: text/plain, Size: 3603 bytes --] From: Yong Zhang <yong.zhang@windriver.com> Otherwise we get a deadlock like below: [ 1044.042749] BUG: scheduling while atomic: ksoftirqd/21/141/0x00010003 [ 1044.042752] INFO: lockdep is turned off. [ 1044.042754] Modules linked in: [ 1044.042757] Pid: 141, comm: ksoftirqd/21 Tainted: G W 3.4.0-rc2-rt3-23676-ga723175-dirty #29 [ 1044.042759] Call Trace: [ 1044.042761] <IRQ> [<ffffffff8107d8e5>] __schedule_bug+0x65/0x80 [ 1044.042770] [<ffffffff8168978c>] __schedule+0x83c/0xa70 [ 1044.042775] [<ffffffff8106bdd2>] ? prepare_to_wait+0x32/0xb0 [ 1044.042779] [<ffffffff81689a5e>] schedule+0x2e/0xa0 [ 1044.042782] [<ffffffff81071ebd>] hrtimer_wait_for_timer+0x6d/0xb0 [ 1044.042786] [<ffffffff8106bb30>] ? wake_up_bit+0x40/0x40 [ 1044.042790] [<ffffffff81071f20>] hrtimer_cancel+0x20/0x40 [ 1044.042794] [<ffffffff8111da0c>] perf_swevent_cancel_hrtimer+0x3c/0x50 [ 1044.042798] [<ffffffff8111da31>] task_clock_event_stop+0x11/0x40 [ 1044.042802] [<ffffffff8111da6e>] task_clock_event_del+0xe/0x10 [ 1044.042805] [<ffffffff8111c568>] event_sched_out+0x118/0x1d0 [ 1044.042809] [<ffffffff8111c649>] group_sched_out+0x29/0x90 [ 1044.042813] [<ffffffff8111ed7e>] __perf_event_disable+0x18e/0x200 [ 1044.042817] [<ffffffff8111c343>] remote_function+0x63/0x70 [ 1044.042821] [<ffffffff810b0aae>] generic_smp_call_function_single_interrupt+0xce/0x120 [ 1044.042826] [<ffffffff81022bc7>] smp_call_function_single_interrupt+0x27/0x40 [ 1044.042831] [<ffffffff8168d50c>] call_function_single_interrupt+0x6c/0x80 [ 1044.042833] <EOI> [<ffffffff811275b0>] ? perf_event_overflow+0x20/0x20 [ 1044.042840] [<ffffffff8168b970>] ? _raw_spin_unlock_irq+0x30/0x70 [ 1044.042844] [<ffffffff8168b976>] ? _raw_spin_unlock_irq+0x36/0x70 [ 1044.042848] [<ffffffff810702e2>] run_hrtimer_softirq+0xc2/0x200 [ 1044.042853] [<ffffffff811275b0>] ? perf_event_overflow+0x20/0x20 [ 1044.042857] [<ffffffff81045265>] __do_softirq_common+0xf5/0x3a0 [ 1044.042862] [<ffffffff81045c3d>] __thread_do_softirq+0x15d/0x200 [ 1044.042865] [<ffffffff81045dda>] run_ksoftirqd+0xfa/0x210 [ 1044.042869] [<ffffffff81045ce0>] ? __thread_do_softirq+0x200/0x200 [ 1044.042873] [<ffffffff81045ce0>] ? __thread_do_softirq+0x200/0x200 [ 1044.042877] [<ffffffff8106b596>] kthread+0xb6/0xc0 [ 1044.042881] [<ffffffff8168b97b>] ? _raw_spin_unlock_irq+0x3b/0x70 [ 1044.042886] [<ffffffff8168d994>] kernel_thread_helper+0x4/0x10 [ 1044.042889] [<ffffffff8107d98c>] ? finish_task_switch+0x8c/0x110 [ 1044.042894] [<ffffffff8168b97b>] ? _raw_spin_unlock_irq+0x3b/0x70 [ 1044.042897] [<ffffffff8168bd5d>] ? retint_restore_args+0xe/0xe [ 1044.042900] [<ffffffff8106b4e0>] ? kthreadd+0x1e0/0x1e0 [ 1044.042902] [<ffffffff8168d990>] ? gs_change+0xb/0xb Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1341476476-5666-1-git-send-email-yong.zhang0@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> --- kernel/events/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index 58690af..4d9159a 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5420,6 +5420,7 @@ static void perf_swevent_init_hrtimer(struct perf_event *event) hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); hwc->hrtimer.function = perf_swevent_hrtimer; + hwc->hrtimer.irqsafe = 1; /* * Since hrtimers have a fixed rate, we can do a static freq->period -- 1.7.10.4 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH RT 8/8] Linux 3.2.22-rt35-rc1 2012-07-12 23:18 [PATCH RT 0/8] [ANNOUNCE] 3.2.22-rt35-rc1 stable review Steven Rostedt ` (6 preceding siblings ...) 2012-07-12 23:18 ` [PATCH RT 7/8] perf: Make swevent hrtimer run in irq instead of softirq Steven Rostedt @ 2012-07-12 23:18 ` Steven Rostedt 7 siblings, 0 replies; 9+ messages in thread From: Steven Rostedt @ 2012-07-12 23:18 UTC (permalink / raw) To: linux-kernel, linux-rt-users; +Cc: Thomas Gleixner, Carsten Emde, John Kacur [-- Attachment #1: 0008-Linux-3.2.22-rt35-rc1.patch --] [-- Type: text/plain, Size: 287 bytes --] From: Steven Rostedt <srostedt@redhat.com> --- localversion-rt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/localversion-rt b/localversion-rt index 21988f9..87569d2 100644 --- a/localversion-rt +++ b/localversion-rt @@ -1 +1 @@ --rt34 +-rt35-rc1 -- 1.7.10.4 ^ permalink raw reply related [flat|nested] 9+ messages in thread
end of thread, other threads:[~2012-07-12 23:19 UTC | newest] Thread overview: 9+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-07-12 23:18 [PATCH RT 0/8] [ANNOUNCE] 3.2.22-rt35-rc1 stable review Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 1/8] Latency histogramms: Cope with backwards running local trace clock Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 2/8] Latency histograms: Adjust timer, if already elapsed when programmed Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 3/8] Disable RT_GROUP_SCHED in PREEMPT_RT_FULL Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 4/8] Latency histograms: Detect another yet overlooked sharedprio condition Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 5/8] slab: Prevent local lock deadlock Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 6/8] fs, jbd: pull your plug when waiting for space Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 7/8] perf: Make swevent hrtimer run in irq instead of softirq Steven Rostedt 2012-07-12 23:18 ` [PATCH RT 8/8] Linux 3.2.22-rt35-rc1 Steven Rostedt
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).