[PATCH] pacct: add pacct_struct to fix some pacct bugs.

The pacct facility need an i/o operation when an accounting record is
generated.  There is a possibility to wake OOM killer up.  If OOM killer is
activated, it kills some processes to make them release process memory
regions.

But acct_process() is called in the killed processes context before calling
exit_mm(), so those processes cannot release own memory.  In the results, any
processes stop in this point and it finally cause a system stall.

1 files changed, 3 insertions, 1 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 601263c0806f..819d82c2efba 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -894,7 +894,7 @@ fastcall NORET_TYPE void do_exit(long code)
         if (group_dead) {
                 hrtimer_cancel(&tsk->signal->real_timer);
                 exit_itimers(tsk->signal);
-                acct_process(code);
+                acct_collect();
         }
         if (unlikely(tsk->robust_list))
                 exit_robust_list(tsk);
@@ -906,6 +906,8 @@ fastcall NORET_TYPE void do_exit(long code)
                 audit_free(tsk);
         exit_mm(tsk);
 
+        if (group_dead)
+                acct_process(code);
         exit_sem(tsk);
         __exit_files(tsk);
         __exit_fs(tsk);