From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752138Ab3KZEbV (ORCPT ); Mon, 25 Nov 2013 23:31:21 -0500 Received: from cantor2.suse.de ([195.135.220.15]:55816 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750901Ab3KZEbU (ORCPT ); Mon, 25 Nov 2013 23:31:20 -0500 Date: Tue, 26 Nov 2013 15:31:06 +1100 From: NeilBrown To: Peter Zijlstra Cc: fengguang.wu@intel.com, "Li, Shaohua" , LKML , Ingo Molnar Subject: Re: kernel BUG at drivers/md/raid5.c:693! Message-ID: <20131126153106.6ae734c0@notabene.brown> In-Reply-To: <20131125095323.GW10022@twins.programming.kicks-ass.net> References: <20131123032205.GB20794@localhost> <20131125103522.6a1c1b36@notabene.brown> <20131125095323.GW10022@twins.programming.kicks-ass.net> X-Mailer: Claws Mail 3.9.2 (GTK+ 2.24.22; x86_64-suse-linux-gnu) Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/nrEUlSL7i4ap.UJKWo9K/be"; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Sig_/nrEUlSL7i4ap.UJKWo9K/be Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Mon, 25 Nov 2013 10:53:23 +0100 Peter Zijlstra wrote: > On Mon, Nov 25, 2013 at 10:35:22AM +1100, NeilBrown wrote: > > Ingo/Peter: is it considered OK to call wake_up while holding a spinloc= k? >=20 > Yes, very much so. Doing a wakeup isn't _that_ expensive. Oh good. Thanks. >=20 > > Could "sleeping spinlocks" affect this at all? (some sample stack trace= s are > > below). >=20 > Not entirely sure, are you referencing to -rt where me make spinlock_t > pi-mutexes? I'm not sure either. Just stabbing in the dark really. The stack trace in the previous email seemed to suggest that a process was blocking inside a wake_up call, but it wasn't at all conclusive. And I've seen a few wake_ups in other stack traces which seem to be connected with other deadlock. Probably some sort of co-incidence. Thanks, NeilBrown --Sig_/nrEUlSL7i4ap.UJKWo9K/be Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIVAwUBUpQkCjnsnt1WYoG5AQLKSRAApDI4zj/SkSRojgZ31ChTeMgyDpa8brOT Z5mDETeH0OZpJ7FSyuc7Gd+32dXydhVdp+Ky2HsUlQb3q5M2FRtDEIlFtNTYROlx 1oVXBx65HiQhM9IdFY6xJH+CvG6xVLzNs0UHN//xtbzKta/4S1EIRRRXpj8YV94Q RdI7bb9A9gpx/uE4r/pIq1vSTA547y777Tec9ndwRgncTVwnWIIbpa0jOUuLitcn 5iNujrfjcYm1sG4jPi8pZwdEiTjCM+uHUWfhzEnc0jLQHpna3/zCa+3JgKqe1O8j lLQuYAW32DL8X7FcVW8Pq5SGg6XZg+yXNPoDxeRJy9E2I0qtUpOo+e5XeOc0wTYJ DiHyjq+zwAAIwTeWfxEE9zzennVcdTuEJX1D5FTpc55qUOjJ/sQxJdopeeMhkzIH b6RWshXzWWFAWkUAtwwn3GgKGQdEkGLu+ME9X+lWnS9eMi2KhjE6eBkUsCwsNNQq WI9rcQEB9I/AAqkagPOaykydXk7okbyFgzWRiBXhLCQsNklkCkxGKxTXFZD9YHss Ggrkkf1NGvm5R7vnAo8UfuMk72k/NRyiworAEkwYzeVJ3YmF5a/bPExD/ixZ9Chq edebveJwyguWAM1hWzj9Yw6PhO6POP4Wv3hhetdBlmRFAseaY9Ewy7lRQf2f8Vi8 1afKZO3OWx4= =FL5n -----END PGP SIGNATURE----- --Sig_/nrEUlSL7i4ap.UJKWo9K/be--