[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.

2 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/acct.h b/include/linux/acct.h
index 3d54fbcf969e..5bca9b3ef2d7 100644
--- a/include/linux/acct.h
+++ b/include/linux/acct.h
@@ -121,12 +121,16 @@ struct vfsmount;
 struct super_block;
 extern void acct_auto_close_mnt(struct vfsmount *m);
 extern void acct_auto_close(struct super_block *sb);
+extern void acct_init_pacct(struct pacct_struct *pacct);
+extern void acct_collect();
 extern void acct_process(long exitcode);
 extern void acct_update_integrals(struct task_struct *tsk);
 extern void acct_clear_integrals(struct task_struct *tsk);
 #else
 #define acct_auto_close_mnt(x)  do { } while (0)
 #define acct_auto_close(x)      do { } while (0)
+#define acct_init_pacct(x)      do { } while (0)
+#define acct_collect()          do { } while (0)
 #define acct_process(x)         do { } while (0)
 #define acct_update_integrals(x)                do { } while (0)
 #define acct_clear_integrals(task)      do { } while (0)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 38b4791e6a5d..abada7c1d5e4 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -358,6 +358,10 @@ struct sighand_struct {
         spinlock_t              siglock;
 };
 
+struct pacct_struct {
+        unsigned long           ac_mem;
+};
+
 /*
  * NOTE! "signal_struct" does not have it's own
  * locking, because a shared signal_struct always
@@ -449,6 +453,9 @@ struct signal_struct {
         struct key *session_keyring;    /* keyring inherited over fork */
         struct key *process_keyring;    /* keyring private to this process */
 #endif
+#ifdef CONFIG_BSD_PROCESS_ACCT
+        struct pacct_struct pacct;      /* per-process accounting information */
+#endif
 };
 
 /* Context switch must be unlocked if interrupts are to be enabled */