Messages in this thread Patch in this message | | | Date | Fri, 21 Apr 2006 22:33:40 -0400 | From | Shailabh Nagar <> | Subject | [Patch 3/8] cpu delay collection via schedstats |
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Changelog
Fixes comments by akpm - comments about locking used in rq_sched_info_arrive/depart
No fix needed/possible - redundant extern declaration of delayacct_on in sched.h suggested location (delayacct.h) cannot be used as it includes sched.h extern declaration moved to where its needed - move unlikely declaration inside sched_info_on Function only returns constants. Cannot be done. - removal of #if defined in sched_fork (Dave Hansen) Refactoring suggested does not work if only SCHEDSTATS is configured
delayacct-shedstats.patch
Make the task-related schedstats functions callable by delay accounting even if schedstats collection isn't turned on. This removes the dependency of delay accounting on schedstats.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com>
include/linux/sched.h | 21 +++++++++++++++--- kernel/sched.c | 56 ++++++++++++++++++++++++++++++++++---------------- 2 files changed, 56 insertions(+), 21 deletions(-)
Index: linux-2.6.17-rc1/include/linux/sched.h =================================================================== --- linux-2.6.17-rc1.orig/include/linux/sched.h 2006-04-21 20:29:13.000000000 -0400 +++ linux-2.6.17-rc1/include/linux/sched.h 2006-04-21 20:29:15.000000000 -0400 @@ -521,7 +521,7 @@ typedef struct prio_array prio_array_t; struct backing_dev_info; struct reclaim_state;
-#ifdef CONFIG_SCHEDSTATS +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) struct sched_info { /* cumulative counters */ unsigned long cpu_time, /* time spent on the cpu */ @@ -532,9 +532,11 @@ struct sched_info { unsigned long last_arrival, /* when we last ran on a cpu */ last_queued; /* when we were last queued to run */ }; +#endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
+#ifdef CONFIG_SCHEDSTATS extern struct file_operations proc_schedstat_operations; -#endif +#endif /* CONFIG_SCHEDSTATS */
#ifdef CONFIG_TASK_DELAY_ACCT struct task_delay_info { @@ -557,8 +559,19 @@ struct task_delay_info { u32 blkio_count; u32 swapin_count; }; -#endif +#endif /* CONFIG_TASK_DELAY_ACCT */
+static inline int sched_info_on(void) +{ +#ifdef CONFIG_SCHEDSTATS + return 1; +#elif defined(CONFIG_TASK_DELAY_ACCT) + extern int delayacct_on; + return delayacct_on; +#else + return 0; +#endif +}
enum idle_type { @@ -744,7 +757,7 @@ struct task_struct { cpumask_t cpus_allowed; unsigned int time_slice, first_time_slice;
-#ifdef CONFIG_SCHEDSTATS +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) struct sched_info sched_info; #endif
Index: linux-2.6.17-rc1/kernel/sched.c =================================================================== --- linux-2.6.17-rc1.orig/kernel/sched.c 2006-04-21 20:29:13.000000000 -0400 +++ linux-2.6.17-rc1/kernel/sched.c 2006-04-21 20:29:15.000000000 -0400 @@ -469,9 +469,32 @@ struct file_operations proc_schedstat_op .release = single_release, };
+/* + * Expects runqueue lock to be held for atomicity of update + */ +static inline void rq_sched_info_arrive(struct runqueue *rq, + unsigned long diff) +{ + if (rq) { + rq->rq_sched_info.run_delay += diff; + rq->rq_sched_info.pcnt++; + } +} + +/* + * Expects runqueue lock to be held for atomicity of update + */ +static inline void rq_sched_info_depart(struct runqueue *rq, + unsigned long diff) +{ + if (rq) + rq->rq_sched_info.cpu_time += diff; +} # define schedstat_inc(rq, field) do { (rq)->field++; } while (0) # define schedstat_add(rq, field, amt) do { (rq)->field += (amt); } while (0) #else /* !CONFIG_SCHEDSTATS */ +static inline void rq_sched_info_arrive(struct runqueue *rq, unsigned long diff) {} +static inline void rq_sched_info_depart(struct runqueue *rq, unsigned long diff) {} # define schedstat_inc(rq, field) do { } while (0) # define schedstat_add(rq, field, amt) do { } while (0) #endif @@ -491,7 +514,7 @@ static inline runqueue_t *this_rq_lock(v return rq; }
-#ifdef CONFIG_SCHEDSTATS +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) /* * Called when a process is dequeued from the active array and given * the cpu. We should note that with the exception of interactive @@ -520,7 +543,6 @@ static inline void sched_info_dequeued(t static void sched_info_arrive(task_t *t) { unsigned long now = jiffies, diff = 0; - struct runqueue *rq = task_rq(t);
if (t->sched_info.last_queued) diff = now - t->sched_info.last_queued; @@ -529,11 +551,7 @@ static void sched_info_arrive(task_t *t) t->sched_info.last_arrival = now; t->sched_info.pcnt++;
- if (!rq) - return; - - rq->rq_sched_info.run_delay += diff; - rq->rq_sched_info.pcnt++; + rq_sched_info_arrive(task_rq(t), diff); }
/* @@ -553,8 +571,9 @@ static void sched_info_arrive(task_t *t) */ static inline void sched_info_queued(task_t *t) { - if (!t->sched_info.last_queued) - t->sched_info.last_queued = jiffies; + if (unlikely(sched_info_on())) + if (!t->sched_info.last_queued) + t->sched_info.last_queued = jiffies; }
/* @@ -563,13 +582,10 @@ static inline void sched_info_queued(tas */ static inline void sched_info_depart(task_t *t) { - struct runqueue *rq = task_rq(t); unsigned long diff = jiffies - t->sched_info.last_arrival;
t->sched_info.cpu_time += diff; - - if (rq) - rq->rq_sched_info.cpu_time += diff; + rq_sched_info_depart(task_rq(t), diff); }
/* @@ -577,7 +593,7 @@ static inline void sched_info_depart(tas * their time slice. (This may also be called when switching to or from * the idle task.) We are only called when prev != next. */ -static inline void sched_info_switch(task_t *prev, task_t *next) +static inline void __sched_info_switch(task_t *prev, task_t *next) { struct runqueue *rq = task_rq(prev);
@@ -592,10 +608,15 @@ static inline void sched_info_switch(tas if (next != rq->idle) sched_info_arrive(next); } +static inline void sched_info_switch(task_t *prev, task_t *next) +{ + if (unlikely(sched_info_on())) + __sched_info_switch(prev, next); +} #else #define sched_info_queued(t) do { } while (0) #define sched_info_switch(t, next) do { } while (0) -#endif /* CONFIG_SCHEDSTATS */ +#endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */
/* * Adding/removing a task to/from a priority array: @@ -1351,8 +1372,9 @@ void fastcall sched_fork(task_t *p, int p->state = TASK_RUNNING; INIT_LIST_HEAD(&p->run_list); p->array = NULL; -#ifdef CONFIG_SCHEDSTATS - memset(&p->sched_info, 0, sizeof(p->sched_info)); +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) + if (unlikely(sched_info_on())) + memset(&p->sched_info, 0, sizeof(p->sched_info)); #endif #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) p->oncpu = 0; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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