From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752128AbaEUJ3p (ORCPT ); Wed, 21 May 2014 05:29:45 -0400 Received: from casper.infradead.org ([85.118.1.10]:38859 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751824AbaEUJ3m (ORCPT ); Wed, 21 May 2014 05:29:42 -0400 Date: Wed, 21 May 2014 11:29:32 +0200 From: Peter Zijlstra To: Oleg Nesterov Cc: Andrew Morton , David Howells , Mel Gorman , Johannes Weiner , Vlastimil Babka , Jan Kara , Michal Hocko , Hugh Dickins , Dave Hansen , Linux Kernel , Linux-MM , Linux-FSDevel , Paul McKenney , Linus Torvalds Subject: Re: [PATCH 1/1] ptrace: task_clear_jobctl_trapping()->wake_up_bit() needs mb() Message-ID: <20140521092932.GH30445@twins.programming.kicks-ass.net> References: <1399974350-11089-1-git-send-email-mgorman@suse.de> <1399974350-11089-20-git-send-email-mgorman@suse.de> <20140513125313.GR23991@suse.de> <20140513141748.GD2485@laptop.programming.kicks-ass.net> <20140514161152.GA2615@redhat.com> <20140514161755.GQ30445@twins.programming.kicks-ass.net> <20140516135116.GA19210@redhat.com> <20140516135137.GB19210@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="N/xU+6Hp+kBwyaPu" Content-Disposition: inline In-Reply-To: <20140516135137.GB19210@redhat.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --N/xU+6Hp+kBwyaPu Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, May 16, 2014 at 03:51:37PM +0200, Oleg Nesterov wrote: > __wake_up_bit() checks waitqueue_active() and thus the caller needs > mb() as wake_up_bit() documents, fix task_clear_jobctl_trapping(). >=20 > Signed-off-by: Oleg Nesterov Seeing how you are one of the ptrace maintainers, how do you want this routed? Does Andrew pick this up, do I stuff it somewhere? > --- > kernel/signal.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) >=20 > diff --git a/kernel/signal.c b/kernel/signal.c > index c2a8542..f4c4119 100644 > --- a/kernel/signal.c > +++ b/kernel/signal.c > @@ -277,6 +277,7 @@ void task_clear_jobctl_trapping(struct task_struct *t= ask) > { > if (unlikely(task->jobctl & JOBCTL_TRAPPING)) { > task->jobctl &=3D ~JOBCTL_TRAPPING; > + smp_mb(); /* advised by wake_up_bit() */ > wake_up_bit(&task->jobctl, JOBCTL_TRAPPING_BIT); > } > } > --=20 > 1.5.5.1 >=20 >=20 --N/xU+6Hp+kBwyaPu Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTfHH8AAoJEHZH4aRLwOS6b/wQALZkfgxJ4sPJJVf0xH/Kht5b DQZDZftR1C4MFxt8oSj86XFTIM4mF8A7iTD3ZJMTteDGnQJD/9yfAZnfwnLJvRff yVRX/+MSpkHEzpLyHE1Be/7v9Tllc/Sc23R0jaYefpfDzwe0zwPq6ZrvV0s4BlM9 B+8k7CrHbZpCSP3B/xj1gJIsW2yS+3/a99fS/1SQcb/FVoFDNFYQJJGf5a30+hKg 9Vieg4HWLUVb+QOAfPEgkz+NyUgURHcVL6IWVNkOCsvFoHPGgHtom67ZczRFeD/0 zGrkTLC5bsg7qbIkRfeTP6NfmUkDBaDgnzaomkAkYIXQv/385qNj8vgcpGPQFrds COWalwk1lhxGMOFRRIMwoYAYPhtgLhngKUZzPfzuNrLJj8xXDSQtVEKx+FfS3PfG 6ktwptdLcU1BDodvP4IGV3x1fMhusuRPcpHKyyqWerkufjYervt3iMntwA1UUuDy HAw0I2zIRfH1hcXotjcu27OlcqC+PQZ4U2JkVcAp0QIZfhwdnN6mvm8sSbgscFjk ZctrPcwW3QNHUEEKm77YxiZang3ZUfQ4n6LTHfIZ975L68zNu5XZEfwy7NNFEzXf TH2OA6J5E6a1E5rSWwhCEjeOjYRobl3L4ISIxiNLZXuh+E8j+ku3J/YOX23RdcOe IhSKOiKVG4y4pqhccpav =A4Gu -----END PGP SIGNATURE----- --N/xU+6Hp+kBwyaPu--