From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: [RFC] uas host lock removal conversion Date: Thu, 16 Dec 2010 07:00:36 -0700 Message-ID: <20101216140035.GD1263@parisc-linux.org> References: <20101216050257.GC1263@parisc-linux.org> <20101216104458.GA5919@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from palinux.external.hp.com ([192.25.206.14]:55115 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756053Ab0LPOAh (ORCPT ); Thu, 16 Dec 2010 09:00:37 -0500 Content-Disposition: inline In-Reply-To: <20101216104458.GA5919@infradead.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Christoph Hellwig Cc: linux-scsi@vger.kernel.org On Thu, Dec 16, 2010 at 05:44:58AM -0500, Christoph Hellwig wrote: > On Wed, Dec 15, 2010 at 10:02:57PM -0700, Matthew Wilcox wrote: > > > > I thought I'd take a crack at removing the host lock from uas. I think > > I can now switch to using GFP_NOIO (since interrupts are enabled by > > scsi_request_fn()), and I have to use _irq spinlocks to protect the list > > that is modified from interrupt context (same reason :-). > > ->qeuecommand can be called from software interrupt context, so you'll > need to stick to GFP_ATOMIC. Ah, I couldn't find a path that did that. Could you point it out to me? I'll send a patch to update that documentation. -- 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."