From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A3253C742B3 for ; Fri, 12 Jul 2019 10:10:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 805922084B for ; Fri, 12 Jul 2019 10:10:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726342AbfGLKKO (ORCPT ); Fri, 12 Jul 2019 06:10:14 -0400 Received: from a.mx.secunet.com ([62.96.220.36]:33376 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726002AbfGLKKO (ORCPT ); Fri, 12 Jul 2019 06:10:14 -0400 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id 719BD20253; Fri, 12 Jul 2019 12:10:13 +0200 (CEST) X-Virus-Scanned: by secunet Received: from a.mx.secunet.com ([127.0.0.1]) by localhost (a.mx.secunet.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id M5Ju-BORThWe; Fri, 12 Jul 2019 12:10:13 +0200 (CEST) Received: from mail-essen-01.secunet.de (mail-essen-01.secunet.de [10.53.40.204]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id 10A11201C1; Fri, 12 Jul 2019 12:10:13 +0200 (CEST) Received: from gauss2.secunet.de (10.182.7.193) by mail-essen-01.secunet.de (10.53.40.204) with Microsoft SMTP Server id 14.3.439.0; Fri, 12 Jul 2019 12:10:12 +0200 Received: by gauss2.secunet.de (Postfix, from userid 1000) id 9ECB0318050B; Fri, 12 Jul 2019 12:10:12 +0200 (CEST) Date: Fri, 12 Jul 2019 12:10:12 +0200 From: Steffen Klassert To: Herbert Xu CC: Daniel Jordan , , , , , , , Subject: Re: [PATCH] padata: use smp_mb in padata_reorder to avoid orphaned padata jobs Message-ID: <20190712101012.GW14601@gauss3.secunet.de> References: <20190711221205.29889-1-daniel.m.jordan@oracle.com> <20190712100636.mqdr567p7ozanlyl@gondor.apana.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20190712100636.mqdr567p7ozanlyl@gondor.apana.org.au> User-Agent: Mutt/1.9.4 (2018-02-28) X-EXCLAIMER-MD-CONFIG: 2c86f778-e09b-4440-8b15-867914633a10 Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Fri, Jul 12, 2019 at 06:06:36PM +0800, Herbert Xu wrote: > Daniel Jordan wrote: > > > > CPU0 CPU1 > > > > padata_reorder padata_do_serial > > LOAD reorder_objects // 0 > > INC reorder_objects // 1 > > padata_reorder > > TRYLOCK pd->lock // failed > > UNLOCK pd->lock > > I think this can't happen because CPU1 won't call padata_reorder > at all as it's the wrong CPU so it gets pushed back onto a work > queue which will go back to CPU0. > > Steffen, could you please take a look at this as there clearly > is a problem here? I'm currently travelling, will have a look at it when I'm back.