Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S942366AbcJSTno (ORCPT ); Wed, 19 Oct 2016 15:43:44 -0400 Received: from mail.fireflyinternet.com ([109.228.58.192]:60058 "EHLO fireflyinternet.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932345AbcJSTnn (ORCPT ); Wed, 19 Oct 2016 15:43:43 -0400 X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Date: Wed, 19 Oct 2016 20:43:33 +0100 From: Chris Wilson To: Christoph Hellwig Cc: Andy Lutomirski , Andrew Morton , joelaf@google.com, jszhang@marvell.com, joaodias@google.com, "linux-mm@kvack.org" , linux-rt-users@vger.kernel.org, "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 2/6] mm: mark all calls into the vmalloc subsystem as potentially sleeping Message-ID: <20161019194333.GD19173@nuc-i3427.alporthouse.com> References: <1476773771-11470-1-git-send-email-hch@lst.de> <1476773771-11470-3-git-send-email-hch@lst.de> <20161019111541.GQ29358@nuc-i3427.alporthouse.com> <20161019130552.GB5876@lst.de> <20161019163112.GA31091@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161019163112.GA31091@lst.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 763 Lines: 20 On Wed, Oct 19, 2016 at 06:31:12PM +0200, Christoph Hellwig wrote: > On Wed, Oct 19, 2016 at 08:34:40AM -0700, Andy Lutomirski wrote: > > > > It would be quite awkward for a task stack to get freed from a > > sleepable context, because the obvious sleepable context is the task > > itself, and it still needs its stack. This was true even in the old > > regime when task stacks were freed from RCU context. > > > > But vfree has a magic automatic deferral mechanism. Couldn't you make > > the non-deferred case might_sleep()? > > But it's only magic from interrupt context.. > > Chris, does this patch make virtually mapped stack work for you again? So far, so good. No warns from anyone else. -Chris -- Chris Wilson, Intel Open Source Technology Centre