Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753993Ab0LTCIE (ORCPT ); Sun, 19 Dec 2010 21:08:04 -0500 Received: from palinux.external.hp.com ([192.25.206.14]:36450 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753388Ab0LTCIB (ORCPT ); Sun, 19 Dec 2010 21:08:01 -0500 Date: Sun, 19 Dec 2010 19:07:59 -0700 From: Matthew Wilcox To: "Nicholas A. Bellinger" Cc: linux-scsi , linux-kernel , James Bottomley , Jeff Garzik , Christoph Hellwig , FUJITA Tomonori , Hannes Reinecke , Mike Christie Subject: Re: [PATCH 01/12] libiscsi: Convert to host_lock less w/ interrupts disabled internally Message-ID: <20101220020758.GK1263@parisc-linux.org> References: <1292793727-31957-1-git-send-email-nab@linux-iscsi.org> <1292793727-31957-2-git-send-email-nab@linux-iscsi.org> <20101219233835.GJ1263@parisc-linux.org> <1292807703.20840.29.camel@haakon2.linux-iscsi.org> <1292808126.20840.33.camel@haakon2.linux-iscsi.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1292808126.20840.33.camel@haakon2.linux-iscsi.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: 1164 Lines: 27 On Sun, Dec 19, 2010 at 05:22:06PM -0800, Nicholas A. Bellinger wrote: > Actually sorry, Mike Christie did already make a clarification on this > subject here: > > http://marc.info/?l=linux-scsi&m=129010439421506&w=2 > > I had originally thought the same that session->lock should be using > some flavour of spin_lock_irq*() as well, but apparently this is not the > case for libiscsi. Right, so it seems. "the session lock is just locked in softirqs/timers" means that it does need to be the _bh() version of spin_lock though. I'm actually not sure ... is it safe to use the _bh versions in BH context? I think it is because the preempt count is nested, unlike the _irq variants of spinlocks. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- 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/