From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Carsten Emde <C.Emde@osadl.org>, John Kacur <jkacur@redhat.com>,
Tony Luck <tony.luck@intel.com>,
stable-rt@vger.kernel.org
Subject: [PATCH RT 09/25][RFC 3.0.23-rt39-rc1] ia64: vsyscall: Use seqcount instead of seqlock
Date: Tue, 06 Mar 2012 11:16:45 -0500 [thread overview]
Message-ID: <20120306161946.789821696@goodmis.org> (raw)
In-Reply-To: 20120306161636.491172179@goodmis.org
[-- Attachment #1: 0009-ia64-vsyscall-Use-seqcount-instead-of-seqlock.patch --]
[-- Type: text/plain, Size: 2626 bytes --]
From: Thomas Gleixner <tglx@linutronix.de>
The update of the vdso data happens under xtime_lock, so adding a
nested lock is pointless. Just use a seqcount to sync the readers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: stable-rt@vger.kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
arch/ia64/kernel/asm-offsets.c | 4 ++--
arch/ia64/kernel/fsys.S | 2 +-
arch/ia64/kernel/fsyscall_gtod_data.h | 2 +-
arch/ia64/kernel/time.c | 10 +++-------
4 files changed, 7 insertions(+), 11 deletions(-)
diff --git a/arch/ia64/kernel/asm-offsets.c b/arch/ia64/kernel/asm-offsets.c
index af56501..106aeb6 100644
--- a/arch/ia64/kernel/asm-offsets.c
+++ b/arch/ia64/kernel/asm-offsets.c
@@ -269,8 +269,8 @@ void foo(void)
BLANK();
/* used by fsys_gettimeofday in arch/ia64/kernel/fsys.S */
- DEFINE(IA64_GTOD_LOCK_OFFSET,
- offsetof (struct fsyscall_gtod_data_t, lock));
+ DEFINE(IA64_GTOD_SEQ_OFFSET,
+ offsetof (struct fsyscall_gtod_data_t, seq);
DEFINE(IA64_GTOD_WALL_TIME_OFFSET,
offsetof (struct fsyscall_gtod_data_t, wall_time));
DEFINE(IA64_GTOD_MONO_TIME_OFFSET,
diff --git a/arch/ia64/kernel/fsys.S b/arch/ia64/kernel/fsys.S
index 331d42b..fa77de7 100644
--- a/arch/ia64/kernel/fsys.S
+++ b/arch/ia64/kernel/fsys.S
@@ -174,7 +174,7 @@ ENTRY(fsys_set_tid_address)
FSYS_RETURN
END(fsys_set_tid_address)
-#if IA64_GTOD_LOCK_OFFSET !=0
+#if IA64_GTOD_SEQ_OFFSET !=0
#error fsys_gettimeofday incompatible with changes to struct fsyscall_gtod_data_t
#endif
#if IA64_ITC_JITTER_OFFSET !=0
diff --git a/arch/ia64/kernel/fsyscall_gtod_data.h b/arch/ia64/kernel/fsyscall_gtod_data.h
index 57d2ee6..146b15b 100644
--- a/arch/ia64/kernel/fsyscall_gtod_data.h
+++ b/arch/ia64/kernel/fsyscall_gtod_data.h
@@ -6,7 +6,7 @@
*/
struct fsyscall_gtod_data_t {
- seqlock_t lock;
+ seqcount_t seq;
struct timespec wall_time;
struct timespec monotonic_time;
cycle_t clk_mask;
diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 85118df..15823ed 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -35,9 +35,7 @@
static cycle_t itc_get_cycles(struct clocksource *cs);
-struct fsyscall_gtod_data_t fsyscall_gtod_data = {
- .lock = __SEQLOCK_UNLOCKED(fsyscall_gtod_data.lock),
-};
+struct fsyscall_gtod_data_t fsyscall_gtod_data;
struct itc_jitter_data_t itc_jitter_data;
@@ -460,9 +458,7 @@ void update_vsyscall_tz(void)
void update_vsyscall(struct timespec *wall, struct timespec *wtm,
struct clocksource *c, u32 mult)
{
- unsigned long flags;
next prev parent reply other threads:[~2012-03-06 16:19 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-06 16:16 [PATCH RT 00/25][RFC 3.0.23-rt39-rc1] [ANNOUNCE] 3.0.23-rt39-rc1 release cycle Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 01/25][RFC 3.0.23-rt39-rc1] revert-convert-xtime_lock-to-raw_seqlock Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 02/25][RFC 3.0.23-rt39-rc1] revert-seqlock-create-raw_seqlock Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 03/25][RFC 3.0.23-rt39-rc1] revert-seqlock-use-seqcount Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 04/25][RFC 3.0.23-rt39-rc1] revert-seqlock-remove-unused-functions Steven Rostedt
2012-03-06 22:39 ` John Kacur
2012-03-06 22:42 ` Thomas Gleixner
2012-03-06 16:16 ` [PATCH RT 05/25][RFC 3.0.23-rt39-rc1] x86-64-remove-vsyscall-number-3 Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 06/25][RFC 3.0.23-rt39-rc1] x86-64-emulate-legacy-vsyscalls Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 07/25][RFC 3.0.23-rt39-rc1] x86: vdso: Remove bogus locking in update_vsyscall_tz() Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 08/25][RFC 3.0.23-rt39-rc1] x86: vdso: Use seqcount instead of seqlock Steven Rostedt
2012-03-06 16:16 ` Steven Rostedt [this message]
2012-03-06 16:16 ` [PATCH RT 10/25][RFC 3.0.23-rt39-rc1] seqlock: Remove unused functions Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 11/25][RFC 3.0.23-rt39-rc1] seqlock: Use seqcount Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 12/25][RFC 3.0.23-rt39-rc1] seqlock: Provide seq_spin_* functions Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 13/25][RFC 3.0.23-rt39-rc1] fs: fs_struct use seqlock Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 14/25][RFC 3.0.23-rt39-rc1] fs: dentry " Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 15/25][RFC 3.0.23-rt39-rc1] timekeeping: Split xtime_lock Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 16/25][RFC 3.0.23-rt39-rc1] seqlock: Prevent rt starvation Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 17/25][RFC 3.0.23-rt39-rc1] fs: Protect open coded isize seqcount Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 18/25][RFC 3.0.23-rt39-rc1] net: u64_stat: Protect seqcount Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 19/25][RFC 3.0.23-rt39-rc1] timer: Fix hotplug for -rt Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 20/25][RFC 3.0.23-rt39-rc1] futex/rt: Fix possible lockup when taking pi_lock in proxy handler Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 21/25][RFC 3.0.23-rt39-rc1] ring-buffer/rt: Check for irqs disabled before grabbing reader lock Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 22/25][RFC 3.0.23-rt39-rc1] sched/rt: Fix wait_task_interactive() to test rt_spin_lock state Steven Rostedt
2012-03-06 16:16 ` [PATCH RT 23/25][RFC 3.0.23-rt39-rc1] lglock/rt: Use non-rt for_each_cpu() in -rt code Steven Rostedt
2012-03-06 16:17 ` [PATCH RT 24/25][RFC 3.0.23-rt39-rc1] cpu: Make hotplug.lock a "sleeping" spinlock on RT Steven Rostedt
2012-03-06 16:17 ` [PATCH RT 25/25][RFC 3.0.23-rt39-rc1] Linux 3.0.23-rt39-rc1 Steven Rostedt
2012-03-06 22:20 ` [PATCH RT 00/25][RFC 3.0.23-rt39-rc1] [ANNOUNCE] 3.0.23-rt39-rc1 release cycle Steven Rostedt
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