sched: fix /proc/<PID>/stat stime/utime monotonicity, part 2

Extend Peter's patch to fix accounting issues, by keeping stime
monotonic too.

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Frans Pop <elendil@planet.nl>

diff --git a/fs/proc/array.c b/fs/proc/array.c
index d80baaabf835e1c98911004035518bf5df7dc51d..eba339ecba27b58e3a39d58d54062d1bdbe3a48f 100644 (file)
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -374,7 +374,8 @@ static cputime_t task_stime(struct task_struct *p)
        stime = nsec_to_clock_t(p->se.sum_exec_runtime) -
                        cputime_to_clock_t(task_utime(p));
 
-       return clock_t_to_cputime(stime);
+       p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime));
+       return p->prev_stime;
 }
 #endif
 

diff --git a/include/linux/sched.h b/include/linux/sched.h
index b0b1fe6e0b17a5c41eb139c66137b4b2a51634c4..155d7438f7ad8b46cdb95939efe42ce8d7a07211 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1009,7 +1009,7 @@ struct task_struct {
        unsigned int rt_priority;
        cputime_t utime, stime, utimescaled, stimescaled;
        cputime_t gtime;
-       cputime_t prev_utime;
+       cputime_t prev_utime, prev_stime;
        unsigned long nvcsw, nivcsw; /* context switch counts */
        struct timespec start_time;             /* monotonic time */
        struct timespec real_start_time;        /* boot based time */

diff --git a/kernel/fork.c b/kernel/fork.c
index a65bfc47177ce7e6c3f6bc68fa7a3b3e1a70dbf2..28a74015198899c3511f3daedbb2412c750c4fe4 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1057,6 +1057,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        p->utimescaled = cputime_zero;
        p->stimescaled = cputime_zero;
        p->prev_utime = cputime_zero;
+       p->prev_stime = cputime_zero;
 
 #ifdef CONFIG_TASK_XACCT
        p->rchar = 0;           /* I/O counter: bytes read */