path: root/kernel/taskstats.c
diff options
authorMaxim Uvarov <muvarov@ru.mvista.com>2007-07-15 23:40:48 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-16 09:05:46 -0700
commitb663a79c191508f27cd885224b592a878c0ba0f6 (patch)
tree270a0472bf1fb0c7323ecb60ec68e40d02dcb1b4 /kernel/taskstats.c
parenta6c15c2b0fbfd5c0a84f5f0e1e3f20f85d2b8692 (diff)
taskstats: add context-switch counters
Make available to the user the following task and process performance statistics: * Involuntary Context Switches (task_struct->nivcsw) * Voluntary Context Switches (task_struct->nvcsw) Statistics information is available from: 1. taskstats interface (Documentation/accounting/) 2. /proc/PID/status (task only). This data is useful for detecting hyperactivity patterns between processes. [akpm@linux-foundation.org: cleanup] Signed-off-by: Maxim Uvarov <muvarov@ru.mvista.com> Cc: Shailabh Nagar <nagar@watson.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jay Lan <jlan@engr.sgi.com> Cc: Jonathan Lim <jlim@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/taskstats.c')
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 906cae77158..059431ed67d 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -196,6 +196,8 @@ static int fill_pid(pid_t pid, struct task_struct *tsk,
/* fill in basic acct fields */
stats->version = TASKSTATS_VERSION;
+ stats->nvcsw = tsk->nvcsw;
+ stats->nivcsw = tsk->nivcsw;
bacct_add_tsk(stats, tsk);
/* fill in extended acct fields */
@@ -242,6 +244,8 @@ static int fill_tgid(pid_t tgid, struct task_struct *first,
delayacct_add_tsk(stats, tsk);
+ stats->nvcsw += tsk->nvcsw;
+ stats->nivcsw += tsk->nivcsw;
} while_each_thread(first, tsk);
unlock_task_sighand(first, &flags);