Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932326Ab2FGNxN (ORCPT ); Thu, 7 Jun 2012 09:53:13 -0400 Received: from mail-lb0-f174.google.com ([209.85.217.174]:59024 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932138Ab2FGNxK (ORCPT ); Thu, 7 Jun 2012 09:53:10 -0400 Message-ID: <4FD0B240.2040101@openvz.org> Date: Thu, 07 Jun 2012 17:53:04 +0400 From: Konstantin Khlebnikov User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.4) Gecko/20120517 Firefox/10.0.4 Iceape/2.7.4 MIME-Version: 1.0 To: Oleg Nesterov CC: Andrew Morton , 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 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> <20120607131848.GA19076@redhat.com> In-Reply-To: <20120607131848.GA19076@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3963 Lines: 115 Oleg Nesterov wrote: > 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. Hmm, ok. Thanks. I think rss-fix must be in stable-3.4.x -- that "BUG..." message can disturb users. Plus via this bug any application can decrease rss down to zero =) > > ------------------------------------------------------------------------------- > [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; -- 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/