Commit 77787bfb authored by KaiGai Kohei's avatar KaiGai Kohei Committed by Linus Torvalds
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[PATCH] pacct: none-delayed process accounting accumulation 



In current 2.6.17 implementation, signal_struct refered from task_struct is
used for per-process data structure.  The pacct facility also uses it as a
per-process data structure to store stime, utime, minflt, majflt.  But those
members are saved in __exit_signal().  It's too late.

For example, if some threads exits at same time, pacct facility has a
possibility to drop accountings for a part of those threads.  (see, the
following 'The results of original 2.6.17 kernel') I think accounting
information should be completely collected into the per-process data structure
before writing out an accounting record.

This patch fixes this matter.  Accumulation of stime, utime, minflt and majflt
are done before generating accounting record.

[mingo@elte.hu: fix acct_collect() siglock bug found by lockdep]
Signed-off-by: default avatarKaiGai Kohei <kaigai@ak.jp.nec.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent f6ec29a4

include/linux/sched.h

+2 −0
Original line number Diff line number Diff line
@@ -362,6 +362,8 @@ struct pacct_struct { 
	int			ac_flag;

	long			ac_exitcode;

	unsigned long		ac_mem;

	cputime_t		ac_utime, ac_stime;

	unsigned long		ac_minflt, ac_majflt;

};



/*

kernel/acct.c

+11 −13
Original line number Diff line number Diff line
@@ -428,7 +428,6 @@ static void do_acct_process(struct file *file) 
	u64 elapsed;

	u64 run_time;

	struct timespec uptime;

	unsigned long jiffies;



	/*

	 * First check to see if there is enough free_space to continue
@@ -469,12 +468,6 @@ static void do_acct_process(struct file *file) 
#endif

	do_div(elapsed, AHZ);

	ac.ac_btime = xtime.tv_sec - elapsed;

	jiffies = cputime_to_jiffies(cputime_add(current->utime,

						 current->signal->utime));

	ac.ac_utime = encode_comp_t(jiffies_to_AHZ(jiffies));

	jiffies = cputime_to_jiffies(cputime_add(current->stime,

						 current->signal->stime));

	ac.ac_stime = encode_comp_t(jiffies_to_AHZ(jiffies));

	/* we really need to bite the bullet and change layout */

	ac.ac_uid = current->uid;

	ac.ac_gid = current->gid;
@@ -497,16 +490,16 @@ static void do_acct_process(struct file *file) 
	read_unlock(&tasklist_lock);



	spin_lock(&current->sighand->siglock);

	ac.ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime)));

	ac.ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime)));

	ac.ac_flag = pacct->ac_flag;

	ac.ac_mem = encode_comp_t(pacct->ac_mem);

	ac.ac_minflt = encode_comp_t(pacct->ac_minflt);

	ac.ac_majflt = encode_comp_t(pacct->ac_majflt);

	ac.ac_exitcode = pacct->ac_exitcode;

	spin_unlock(&current->sighand->siglock);

	ac.ac_io = encode_comp_t(0 /* current->io_usage */);	/* %% */

	ac.ac_rw = encode_comp_t(ac.ac_io / 1024);

	ac.ac_minflt = encode_comp_t(current->signal->min_flt +

				     current->min_flt);

	ac.ac_majflt = encode_comp_t(current->signal->maj_flt +

				     current->maj_flt);

	ac.ac_swaps = encode_comp_t(0);



	/*
@@ -532,6 +525,7 @@ static void do_acct_process(struct file *file) 
void acct_init_pacct(struct pacct_struct *pacct)

{

	memset(pacct, 0, sizeof(struct pacct_struct));

	pacct->ac_utime = pacct->ac_stime = cputime_zero;

}



/**
@@ -555,7 +549,7 @@ void acct_collect(long exitcode, int group_dead) 
		up_read(&current->mm->mmap_sem);

	}



	spin_lock(&current->sighand->siglock);

	spin_lock_irq(&current->sighand->siglock);

	if (group_dead)

		pacct->ac_mem = vsize / 1024;

	if (thread_group_leader(current)) {
@@ -569,7 +563,11 @@ void acct_collect(long exitcode, int group_dead) 
		pacct->ac_flag |= ACORE;

	if (current->flags & PF_SIGNALED)

		pacct->ac_flag |= AXSIG;

	spin_unlock(&current->sighand->siglock);

	pacct->ac_utime = cputime_add(pacct->ac_utime, current->utime);

	pacct->ac_stime = cputime_add(pacct->ac_stime, current->stime);

	pacct->ac_minflt += current->min_flt;

	pacct->ac_majflt += current->maj_flt;

	spin_unlock_irq(&current->sighand->siglock);

}



/**

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