Messages in this thread Patch in this message | | | Date | Wed, 26 Jan 2011 19:11:33 +0800 | From | Yong Zhang <> | Subject | Re: [PATCH 01/18] move do_timer() from kernel/timer.c into kernel/time/timekeeping.c |
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On Wed, Jan 26, 2011 at 11:03:56AM +0100, Peter Zijlstra wrote: > On Wed, 2011-01-26 at 13:56 +0800, Yong Zhang wrote: > > > > +static __init void start_calc_global_timer() > > +{ > > + calc_load_update = jiffies + LOAD_FREQ; > > That should really be done where it was done in sched_init(), otherwise > rq->calc_load_update and this get out of sync.
Ah, yes. Will update.
--- From: Peter Zijlstra <a.p.zijlstra@chello.nl> Subject: [PATCH V2] sched: Move the calc_global_load() call into the scheduler
Remove the calc_global_load() call from the timekeeping code and make it local to the scheduler.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> --- include/linux/sched.h | 2 -- kernel/sched.c | 31 ++++++++++++++++++++++--------- kernel/timer.c | 1 - 3 files changed, 22 insertions(+), 12 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h index d747f94..f224dcc 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -142,8 +142,6 @@ extern unsigned long nr_iowait_cpu(int cpu); extern unsigned long this_cpu_load(void); -extern void calc_global_load(unsigned long ticks); - extern unsigned long get_parent_ip(unsigned long addr); struct seq_file; diff --git a/kernel/sched.c b/kernel/sched.c index 18d38e4..7bbc743 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3159,7 +3159,7 @@ calc_load_n(unsigned long load, unsigned long exp, * Once we've updated the global active value, we need to apply the exponential * weights adjusted to the number of cycles missed. */ -static void calc_global_nohz(unsigned long ticks) +static void calc_global_nohz(void) { long delta, active, n; @@ -3179,8 +3179,9 @@ static void calc_global_nohz(unsigned long ticks) /* * If we were idle for multiple load cycles, apply them. */ - if (ticks >= LOAD_FREQ) { - n = ticks / LOAD_FREQ; + delta = jiffies - calc_load_update - 10; + if (delta >= LOAD_FREQ) { + n = delta / LOAD_FREQ; active = atomic_long_read(&calc_load_tasks); active = active > 0 ? active * FIXED_1 : 0; @@ -3213,7 +3214,7 @@ static inline long calc_load_fold_idle(void) return 0; } -static void calc_global_nohz(unsigned long ticks) +static void calc_global_nohz(void) { } #endif @@ -3233,18 +3234,26 @@ void get_avenrun(unsigned long *loads, unsigned long offset, int shift) loads[2] = (avenrun[2] + offset) << shift; } +static void calc_global_load(unsigned long __data); + +static struct timer_list global_load_timer = + TIMER_DEFERRED_INITIALIZER(calc_global_load, 0, 0); + +static __init void start_calc_global_timer(void) +{ + set_timer_slack(&global_load_timer, 0); + mod_timer(&global_load_timer, calc_load_update + 10); +} + /* * calc_load - update the avenrun load estimates 10 ticks after the * CPUs have updated calc_load_tasks. */ -void calc_global_load(unsigned long ticks) +static void calc_global_load(unsigned long __data) { long active; - calc_global_nohz(ticks); - - if (time_before(jiffies, calc_load_update + 10)) - return; + calc_global_nohz(); active = atomic_long_read(&calc_load_tasks); active = active > 0 ? active * FIXED_1 : 0; @@ -3254,6 +3263,7 @@ void calc_global_load(unsigned long ticks) avenrun[2] = calc_load(avenrun[2], EXP_15, active); calc_load_update += LOAD_FREQ; + mod_timer(&global_load_timer, calc_load_update + 10); } /* @@ -7741,6 +7751,8 @@ void __init sched_init_smp(void) { cpumask_var_t non_isolated_cpus; + start_calc_global_timer(); + alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); alloc_cpumask_var(&fallback_doms, GFP_KERNEL); @@ -7777,6 +7789,7 @@ void __init sched_init_smp(void) #else void __init sched_init_smp(void) { + start_calc_global_timer(); sched_init_granularity(); } #endif /* CONFIG_SMP */ diff --git a/kernel/timer.c b/kernel/timer.c index 43ca993..afdc13b 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1303,7 +1303,6 @@ void do_timer(unsigned long ticks) { jiffies_64 += ticks; update_wall_time(); - calc_global_load(ticks); } #ifdef __ARCH_WANT_SYS_ALARM -- 1.7.1
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