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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 DA322C433DF for ; Thu, 18 Jun 2020 07:57:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C2C9C20899 for ; Thu, 18 Jun 2020 07:57:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728394AbgFRH5t (ORCPT ); Thu, 18 Jun 2020 03:57:49 -0400 Received: from helcar.hmeau.com ([216.24.177.18]:60480 "EHLO fornost.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728218AbgFRH5r (ORCPT ); Thu, 18 Jun 2020 03:57:47 -0400 Received: from gwarestrin.arnor.me.apana.org.au ([192.168.0.7]) by fornost.hmeau.com with smtp (Exim 4.92 #5 (Debian)) id 1jlpQV-0002BA-26; Thu, 18 Jun 2020 17:57:36 +1000 Received: by gwarestrin.arnor.me.apana.org.au (sSMTP sendmail emulation); Thu, 18 Jun 2020 17:57:35 +1000 Date: Thu, 18 Jun 2020 17:57:35 +1000 From: Herbert Xu To: Daniel Jordan Cc: Steffen Klassert , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] padata: upgrade smp_mb__after_atomic to smp_mb in padata_do_serial Message-ID: <20200618075734.GH10091@gondor.apana.org.au> References: <20200608212652.3469814-1-daniel.m.jordan@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200608212652.3469814-1-daniel.m.jordan@oracle.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 08, 2020 at 05:26:52PM -0400, Daniel Jordan wrote: > A 5.7 kernel hangs during a tcrypt test of padata that waits for an AEAD > request to finish. This is only seen on large machines running many > concurrent requests. > > The issue is that padata never serializes the request. The removal of > the reorder_objects atomic missed that the memory barrier in > padata_do_serial() depends on it. > > Upgrade the barrier from smp_mb__after_atomic to smp_mb to get correct > ordering again. > > Fixes: 3facced7aeed1 ("padata: remove reorder_objects") > Signed-off-by: Daniel Jordan > Cc: Herbert Xu > Cc: Steffen Klassert > Cc: linux-crypto@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > --- > kernel/padata.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) Patch applied. Thanks. -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt