Messages in this thread Patch in this message | | | From | Vaidyanathan Srinivasan <> | Subject | [RFC PATCH v1 2/3] Make calls to account_scaled_stats | Date | Mon, 26 May 2008 20:01:46 +0530 |
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Hook various accounting functions to call scaled stats
* Hook porcess contect switch: __switch_to() * Hook IRQ handling account_system_vtime() in hardirq.hA * Update __delayacct_add_tsk() to take care of scaling by 1000 * Update bacct_add_tsk() to take care of scaling by 1000
Signed-off-by: Amit K. Arora <aarora@linux.vnet.ibm.com> Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> ---
arch/x86/kernel/process_32.c | 8 ++++++++ include/linux/hardirq.h | 4 ++++ kernel/delayacct.c | 7 ++++++- kernel/timer.c | 2 -- kernel/tsacct.c | 10 ++++++++-- 5 files changed, 26 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index f8476df..c81a783 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -56,6 +56,9 @@ #include <asm/cpu.h> #include <asm/kdebug.h> +extern void account_scaled_stats(struct task_struct *tsk); +extern void reset_for_scaled_stats(struct task_struct *tsk); + asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); static int hlt_counter; @@ -660,6 +663,11 @@ struct task_struct * __switch_to(struct task_struct *prev_p, struct task_struct loadsegment(gs, next->gs); x86_write_percpu(current_task, next_p); + /* Account scaled statistics for the task leaving CPU */ + account_scaled_stats(prev_p); + barrier(); + /* Initialise stats counter for new task */ + reset_for_scaled_stats(next_p); return prev_p; } diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 181006c..4458736 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -7,6 +7,9 @@ #include <asm/hardirq.h> #include <asm/system.h> +/* TBD: Add config option */ +extern void account_scaled_stats(struct task_struct *tsk); + /* * We put the hardirq and softirq counter into the preemption * counter. The bitmask has the following meaning: @@ -115,6 +118,7 @@ struct task_struct; #ifndef CONFIG_VIRT_CPU_ACCOUNTING static inline void account_system_vtime(struct task_struct *tsk) { + account_scaled_stats(tsk); } #endif diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 10e43fd..3e2938f 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -117,7 +117,12 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) tmp = (s64)d->cpu_scaled_run_real_total; cputime_to_timespec(tsk->utimescaled + tsk->stimescaled, &ts); - tmp += timespec_to_ns(&ts); + /* HACK: Remember, we multipled the cputime_t by 1000 to include + * fraction. Now it is time to scale it back to correct 'ns' value. + * Perhaps, we should use nano second unit (u64 type) for utimescaled + * and stimescaled? + */ + tmp += div_s64(timespec_to_ns(&ts),1000); d->cpu_scaled_run_real_total = (tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp; diff --git a/kernel/timer.c b/kernel/timer.c index ceacc66..de8a615 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -964,10 +964,8 @@ void account_process_tick(struct task_struct *p, int user_tick) if (user_tick) { account_user_time(p, one_jiffy); - account_user_time_scaled(p, cputime_to_scaled(one_jiffy)); } else { account_system_time(p, HARDIRQ_OFFSET, one_jiffy); - account_system_time_scaled(p, cputime_to_scaled(one_jiffy)); } } #endif diff --git a/kernel/tsacct.c b/kernel/tsacct.c index 4ab1b58..ee0d93b 100644 --- a/kernel/tsacct.c +++ b/kernel/tsacct.c @@ -62,10 +62,16 @@ void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk) rcu_read_unlock(); stats->ac_utime = cputime_to_msecs(tsk->utime) * USEC_PER_MSEC; stats->ac_stime = cputime_to_msecs(tsk->stime) * USEC_PER_MSEC; + /* HACK: cputime unit is jiffies on x86 and not good for fractional + * additional. cputime_t type {u,s}timescaled is multiplied by + * 1000 for scaled accounting. Hence, cputime_to_msecs will actually + * give the required micro second value. The multiplier + * USEC_PER_MSEC has been dropped. + */ stats->ac_utimescaled = - cputime_to_msecs(tsk->utimescaled) * USEC_PER_MSEC; + cputime_to_msecs(tsk->utimescaled); stats->ac_stimescaled = - cputime_to_msecs(tsk->stimescaled) * USEC_PER_MSEC; + cputime_to_msecs(tsk->stimescaled); stats->ac_minflt = tsk->min_flt; stats->ac_majflt = tsk->maj_flt;
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