Re: [PATCH] mm: sync rss-counters at the end of exit_mm()
From: KOSAKI Motohiro
Date: Mon Apr 09 2012 - 17:05:18 EST
On Mon, Apr 9, 2012 at 4:03 PM, Konstantin Khlebnikov
<khlebnikov@xxxxxxxxxx> wrote:
> On task's exit do_exit() calls sync_mm_rss() but this is not enough,
> there can be page-faults after this point, for example exit_mm() ->
> mm_release() -> put_user() (for processing tsk->clear_child_tid).
> Thus there may be some rss-counters delta in current->rss_stat.
Seems reasonable. but I have another question. Do we have any reason to
keep sync_mm_rss() in do_exit()? I havn't seen any reason that thread exiting
makes rss consistency.
>
> Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx>
> Reported-by: Markus Trippelsdorf <markus@xxxxxxxxxxxxxxx>
> Cc: Hugh Dickins <hughd@xxxxxxxxxx>
> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
> ---
> kernel/exit.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/exit.c b/kernel/exit.c
> index d8bd3b42..8e09dbe 100644
> --- a/kernel/exit.c
> +++ b/kernel/exit.c
> @@ -683,6 +683,7 @@ static void exit_mm(struct task_struct * tsk)
> enter_lazy_tlb(mm, current);
> task_unlock(tsk);
> mm_update_next_owner(mm);
> + sync_mm_rss(mm);
> mmput(mm);
> }
>
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@xxxxxxxxxx For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
> Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/