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Commit c66f08be authored by Michael Neuling's avatar Michael Neuling Committed by Linus Torvalds
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Add scaled time to taskstats based process accounting 



This adds items to the taststats struct to account for user and system
time based on scaling the CPU frequency and instruction issue rates.

Adds account_(user|system)_time_scaled callbacks which architectures
can use to account for time using this mechanism.

Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@engr.sgi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 898eb71c

include/linux/kernel_stat.h

+2 −0
Original line number Diff line number Diff line
@@ -53,7 +53,9 @@ static inline int kstat_irqs(int irq) 
}



extern void account_user_time(struct task_struct *, cputime_t);

extern void account_user_time_scaled(struct task_struct *, cputime_t);

extern void account_system_time(struct task_struct *, int, cputime_t);

extern void account_system_time_scaled(struct task_struct *, cputime_t);

extern void account_steal_time(struct task_struct *, cputime_t);



#endif /* _LINUX_KERNEL_STAT_H */

include/linux/sched.h

+1 −1
Original line number Diff line number Diff line
@@ -991,7 +991,7 @@ struct task_struct { 
	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */



	unsigned int rt_priority;

	cputime_t utime, stime;

	cputime_t utime, stime, utimescaled, stimescaled;

	cputime_t gtime;

	unsigned long nvcsw, nivcsw; /* context switch counts */

	struct timespec start_time; 		/* monotonic time */

include/linux/taskstats.h

+9 −2
Original line number Diff line number Diff line
@@ -31,7 +31,7 @@ 
 */





#define TASKSTATS_VERSION	5

#define TASKSTATS_VERSION	6

#define TS_COMM_LEN		32	/* should be >= TASK_COMM_LEN

					 * in linux/sched.h */
@@ -85,9 +85,12 @@ struct taskstats { 
	 * On some architectures, value will adjust for cpu time stolen

	 * from the kernel in involuntary waits due to virtualization.

	 * Value is cumulative, in nanoseconds, without a corresponding count

	 * and wraps around to zero silently on overflow

	 * and wraps around to zero silently on overflow.  The

	 * _scaled_ version accounts for cpus which can scale the

	 * number of instructions executed each cycle.

	 */

	__u64	cpu_run_real_total;

	__u64	cpu_scaled_run_real_total;



	/* cpu "virtual" running time

	 * Uses time intervals seen by the kernel i.e. no adjustment
@@ -142,6 +145,10 @@ struct taskstats { 
	__u64	write_char;		/* bytes written */

	__u64	read_syscalls;		/* read syscalls */

	__u64	write_syscalls;		/* write syscalls */



	/* time accounting for SMT machines */

	__u64	ac_utimescaled;		/* utime scaled on frequency etc */

	__u64	ac_stimescaled;		/* stime scaled on frequency etc */

	/* Extended accounting fields end */



#define TASKSTATS_HAS_IO_ACCOUNTING

kernel/delayacct.c

+6 −0
Original line number Diff line number Diff line
@@ -115,6 +115,12 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) 
	tmp += timespec_to_ns(&ts);

	d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp;



	tmp = (s64)d->cpu_scaled_run_real_total;

	cputime_to_timespec(tsk->utimescaled + tsk->stimescaled, &ts);

	tmp += timespec_to_ns(&ts);

	d->cpu_scaled_run_real_total =

		(tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp;



	/*

	 * No locking available for sched_info (and too expensive to add one)

	 * Mitigate by taking snapshot of values

kernel/fork.c

+2 −0
Original line number Diff line number Diff line
@@ -1059,6 +1059,8 @@ static struct task_struct *copy_process(unsigned long clone_flags, 
	p->utime = cputime_zero;

	p->stime = cputime_zero;

	p->gtime = cputime_zero;

	p->utimescaled = cputime_zero;

	p->stimescaled = cputime_zero;



#ifdef CONFIG_TASK_XACCT

	p->rchar = 0;		/* I/O counter: bytes read */