From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754595Ab0C1NCe (ORCPT ); Sun, 28 Mar 2010 09:02:34 -0400 Received: from ppa01.Princeton.EDU ([128.112.128.213]:57368 "EHLO ppa01.Princeton.EDU" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754543Ab0C1NCc (ORCPT ); Sun, 28 Mar 2010 09:02:32 -0400 Date: Sat, 27 Mar 2010 22:08:51 -0400 From: Yury Polyanskiy To: Joel Becker Cc: linux-kernel@vger.kernel.org, Andrew Morton , john stultz , Jan Glauber Subject: Re: [PATCH] hangcheck-timer is broken on x86 Message-ID: <20100327220851.7d0962b9@penta.localdomain> In-Reply-To: <20100327233630.GB1810@mail.oracle.com> References: <20100323233611.6dcbe4f4@penta.localdomain> <20100326214648.GF9984@mail.oracle.com> <20100326180025.052d930f@penta.localdomain> <20100327005710.GA31009@mail.oracle.com> <20100326220259.702859e9@penta.localdomain> <20100327220355.GA1810@mail.oracle.com> <20100327233630.GB1810@mail.oracle.com> X-Mailer: Claws Mail 3.7.5 (GTK+ 2.18.6; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/2fMY8BM6F8zaMr_oKP/vW=a"; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Sig_/2fMY8BM6F8zaMr_oKP/vW=a Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Sat, 27 Mar 2010 16:36:30 -0700 Joel Becker wrote: > On Sat, Mar 27, 2010 at 06:51:01PM -0400, Yury Polyanskiy wrote: > > > =C2=A0 =C2=A0 =C2=A0 =C2=A0It's OK to tell hangcheck-timer users that= suspend is not > > > allowed. =C2=A0After all, you're running something that you don't wan= t to see > > > hang. > >=20 > > Joel, what I am saying is exactly the opposite: it is totally ok to > > suspend-resume with hangcheck-timer (jiffies are stopped and so is > > getrawmonotonic() when system suspended). >=20 > Nope. The point of hangcheck-timer is that it reboots should > the system not be running for a certain amountof time. If > suspend-resume is allowed, a system can resume after days and think it > wasn't more than a second. hangcheck-timer will not know to reboot. But what is the reason for rebooting? Hangcheck is supposed to reboot the machine only if the timer handler was run too late. However, jiffies-based timers DO NOT count time spent in suspend. Y --Sig_/2fMY8BM6F8zaMr_oKP/vW=a Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iEYEARECAAYFAkuuujMACgkQemuRe3zuqOQosACeORtoTc6v2CXkn9YBGv+cYsNm I4cAoKzfE4RXgCTG6fZFR1+Gw5vUtHsR =lNCk -----END PGP SIGNATURE----- --Sig_/2fMY8BM6F8zaMr_oKP/vW=a--