From 81d50bb254ed53a0da45a65988e4e1fa08e8a541 Mon Sep 17 00:00:00 2001 From: Hiroshi Shimamoto Date: Thu, 15 May 2008 19:42:49 -0700 Subject: posix-timers: print RT watchdog message It's useful to detect which process is killed by RT watchdog. Signed-off-by: Hiroshi Shimamoto Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/posix-cpu-timers.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index f1525ad06cb..c42a03aef36 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1037,6 +1037,9 @@ static void check_thread_timers(struct task_struct *tsk, sig->rlim[RLIMIT_RTTIME].rlim_cur += USEC_PER_SEC; } + printk(KERN_INFO + "RT Watchdog Timeout: %s[%d]\n", + tsk->comm, task_pid_nr(tsk)); __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); } } -- cgit v1.2.3-18-g5258 From d031476408ae0f5196e3c579f519dfdefb099b67 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Fri, 23 May 2008 14:41:19 +0100 Subject: hrtimer: remove warning in hres_timers_resume hres_timers_resume() warns if there appears to be more than one cpu online. This warning makes sense when the suspend/resume mechanism offlines all cpus but one during the suspend/resume process. However, Xen suspend does not need to offline the other cpus; it merely keeps them tied up in stop_machine() while the virtual machine is suspended. The warning hres_timers_resume issues is therefore spurious. Signed-off-by: Jeremy Fitzhardinge Cc: xen-devel Cc: "Rafael J. Wysocki" Signed-off-by: Thomas Gleixner --- kernel/hrtimer.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 421be5fe5cc..493c4b8b8cb 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -632,8 +632,6 @@ void clock_was_set(void) */ void hres_timers_resume(void) { - WARN_ON_ONCE(num_online_cpus() > 1); - /* Retrigger the CPU local events: */ retrigger_next_event(NULL); } -- cgit v1.2.3-18-g5258 From 900cfa46191a7d87cf1891924cb90499287fd235 Mon Sep 17 00:00:00 2001 From: "Carlos R. Mafra" Date: Thu, 22 May 2008 19:25:11 -0300 Subject: hrtimer: Remove unused variables in ktime_divns() The variables dns and inc are not used, remove them. Signed-off-by: Carlos R. Mafra Cc: tglx@linutronix.de Signed-off-by: Thomas Gleixner --- kernel/hrtimer.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 493c4b8b8cb..635739d219d 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -300,11 +300,10 @@ EXPORT_SYMBOL_GPL(ktime_sub_ns); */ u64 ktime_divns(const ktime_t kt, s64 div) { - u64 dclc, inc, dns; + u64 dclc; int sft = 0; - dclc = dns = ktime_to_ns(kt); - inc = div; + dclc = ktime_to_ns(kt); /* Make sure the divisor is less than 2^32: */ while (div >> 32) { sft++; -- cgit v1.2.3-18-g5258 From 7a14ce1d8c1d3a6118d406e64eaf9aa70375e085 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 12 May 2008 15:43:53 +0200 Subject: nohz: reduce jiffies polling overhead Signed-off-by: Ingo Molnar --- kernel/time/tick-sched.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'kernel') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index b854a895591..cb75394ed00 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -48,6 +48,13 @@ static void tick_do_update_jiffies64(ktime_t now) unsigned long ticks = 0; ktime_t delta; + /* + * Do a quick check without holding xtime_lock: + */ + delta = ktime_sub(now, last_jiffies_update); + if (delta.tv64 < tick_period.tv64) + return; + /* Reevalute with xtime_lock held */ write_seqlock(&xtime_lock); -- cgit v1.2.3-18-g5258 From 857f3fd7a496ddf4329345af65a4a2b16dd25fe8 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Fri, 11 Jul 2008 11:09:22 +0200 Subject: nohz: don't stop idle tick if softirqs are pending. In case a cpu goes idle but softirqs are pending only an error message is printed to the console. It may take a very long time until the pending softirqs will finally be executed. Worst case would be a hanging system. With this patch the timer tick just continues and the softirqs will be executed after the next interrupt. Still a delay but better than a hanging system. Currently we have at least two device drivers on s390 which under certain circumstances schedule a tasklet from process context. This is a reason why we can end up with pending softirqs when going idle. Fixing these drivers seems to be non-trivial. However there is no question that the drivers should be fixed. This patch shouldn't be considered as a bug fix. It just is intended to keep a system running even if device drivers are buggy. Signed-off-by: Heiko Carstens Cc: Jan Glauber Cc: Stefan Weinhuber Cc: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/time/tick-sched.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index cb75394ed00..86baa4f0dfe 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -235,6 +235,7 @@ void tick_nohz_stop_sched_tick(void) local_softirq_pending()); ratelimit++; } + goto end; } ts->idle_calls++; -- cgit v1.2.3-18-g5258