Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760401Ab2FGNUt (ORCPT ); Thu, 7 Jun 2012 09:20:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:1026 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760213Ab2FGNUr (ORCPT ); Thu, 7 Jun 2012 09:20:47 -0400 Date: Thu, 7 Jun 2012 15:18:48 +0200 From: Oleg Nesterov To: Konstantin Khlebnikov , Andrew Morton Cc: Martin Mokrejs , LKML , "markus@trippelsdorf.de" , "hughd@google.com" , "kamezawa.hiroyu@jp.fujitsu.com" , Michal Hocko , "linux-mm@kvack.org" Subject: Re: 3.4-rc7: BUG: Bad rss-counter state mm:ffff88040b56f800 idx:1 val:-59 Message-ID: <20120607131848.GA19076@redhat.com> References: <4FBC1618.5010408@fold.natur.cuni.cz> <20120522162835.c193c8e0.akpm@linux-foundation.org> <20120522162946.2afcdb50.akpm@linux-foundation.org> <20120523172146.GA27598@redhat.com> <4FC52F17.20709@openvz.org> <20120530171158.GA8614@redhat.com> <4FD05F75.1050108@openvz.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4FD05F75.1050108@openvz.org> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3570 Lines: 111 On 06/07, Konstantin Khlebnikov wrote: > > Oleg Nesterov wrote: >> >> I'll write the changelog and send the patch tomorrow. > > Ding! Week is over, or I missed something? ) Pong ;) I have sent the patch on May 31, see http://marc.info/?l=linux-kernel&m=133848759505805 Also attached below, just in case. Initiallly I sent 2 patches, see http://marc.info/?l=linux-kernel&m=133848784705941 but 2/2 (your patch) was already merged. ------------------------------------------------------------------------------- [PATCH] correctly synchronize rss-counters at exit/exec A simplified version of Konstantin Khlebnikov's patch. do_exit() and exec_mmap() call sync_mm_rss() before mm_release() does put_user(clear_child_tid) which can update task->rss_stat and thus make mm->rss_stat inconsistent. This triggers the "BUG:" printk in check_mm(). - Move the final sync_mm_rss() from do_exit() to exit_mm(), and change exec_mmap() to call sync_mm_rss() after mm_release() to make check_mm() happy. Perhaps we should simply move it into mm_release() and call it unconditionally to catch the "task->rss_stat != 0 && !task->mm" bugs. - Since taskstats_exit() is called before exit_mm(), add another sync_mm_rss() into xacct_add_tsk() who actually uses rss_stat. Probably we should also shift acct_update_integrals(). Reported-by: Markus Trippelsdorf Tested-by: Martin Mokrejs Signed-off-by: Oleg Nesterov Acked-by: Konstantin Khlebnikov --- fs/exec.c | 2 +- kernel/exit.c | 5 ++--- kernel/tsacct.c | 1 + 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 52c9e2f..e49e3c2 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -823,10 +823,10 @@ static int exec_mmap(struct mm_struct *mm) /* Notify parent that we're no longer interested in the old VM */ tsk = current; old_mm = current->mm; - sync_mm_rss(old_mm); mm_release(tsk, old_mm); if (old_mm) { + sync_mm_rss(old_mm); /* * Make sure that if there is a core dump in progress * for the old mm, we get out and die instead of going diff --git a/kernel/exit.c b/kernel/exit.c index ab972a7..b3a84b5 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -655,6 +655,8 @@ static void exit_mm(struct task_struct * tsk) mm_release(tsk, mm); if (!mm) return; + + sync_mm_rss(mm); /* * Serialize with any possible pending coredump. * We must hold mmap_sem around checking core_state @@ -965,9 +967,6 @@ void do_exit(long code) preempt_count()); acct_update_integrals(tsk); - /* sync mm's RSS info before statistics gathering */ - if (tsk->mm) - sync_mm_rss(tsk->mm); group_dead = atomic_dec_and_test(&tsk->signal->live); if (group_dead) { hrtimer_cancel(&tsk->signal->real_timer); diff --git a/kernel/tsacct.c b/kernel/tsacct.c index 23b4d78..a64ee90 100644 --- a/kernel/tsacct.c +++ b/kernel/tsacct.c @@ -91,6 +91,7 @@ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p) stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE / MB; mm = get_task_mm(p); if (mm) { + sync_mm_rss(mm); /* adjust to KB unit */ stats->hiwater_rss = get_mm_hiwater_rss(mm) * PAGE_SIZE / KB; stats->hiwater_vm = get_mm_hiwater_vm(mm) * PAGE_SIZE / KB; -- 1.5.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/