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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B4ACCDB47E for ; Mon, 16 Oct 2023 01:26:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229567AbjJPB0Z (ORCPT ); Sun, 15 Oct 2023 21:26:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58334 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229459AbjJPB0Z (ORCPT ); Sun, 15 Oct 2023 21:26:25 -0400 Received: from wxsgout04.xfusion.com (wxsgout03.xfusion.com [36.139.52.80]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E490A9; Sun, 15 Oct 2023 18:26:20 -0700 (PDT) Received: from wuxshcsitd00600.xfusion.com (unknown [10.32.133.213]) by wxsgout04.xfusion.com (SkyGuard) with ESMTPS id 4S7zs85ws4z9xg13; Mon, 16 Oct 2023 09:23:40 +0800 (CST) Received: from localhost (10.82.147.3) by wuxshcsitd00600.xfusion.com (10.32.133.213) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Mon, 16 Oct 2023 09:25:59 +0800 Date: Mon, 16 Oct 2023 09:25:59 +0800 From: Wang Jinchao To: Daniel Jordan CC: Steffen Klassert , , , Subject: Re: [PATCH v3] Fixes: 07928d9bfc81 ("padata: Remove broken queue flushing") Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: X-Originating-IP: [10.82.147.3] X-ClientProxiedBy: wuxshcsitd00600.xfusion.com (10.32.133.213) To wuxshcsitd00600.xfusion.com (10.32.133.213) Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Fri, Oct 13, 2023 at 11:22:03AM -0400, Daniel Jordan wrote: > Hi, > > On Sat, Oct 07, 2023 at 11:52:33AM +0800, Wang Jinchao wrote: > > Signed-off-by: Wang Jinchao > > The Fixes: tag should be near your Signed-off-by:, and the subject of > the patch should be something descriptive like > > padata: Fix refcnt handling in padata_free_shell() > > Here's some documentation about this: > > https://docs.kernel.org/process/5.Posting.html#patch-formatting-and-changelogs > Updated in patch v4. > > Acked-by: Daniel Jordan > > --- > > V3: > > Include Daniel's ack > > > > V2: https://lore.kernel.org/all/ZRTLHY5A+VqIKhA2@fedora/ > > To satisfy Sparse, use rcu_dereference_protected. > > Reported-by: kernel test robot > > Closes: https://lore.kernel.org/oe-kbuild-all/202309270829.xHgTOMKw-lkp@intel.com/ > > These two tags can also go near your SoB. > >From intel kernel test robot: If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot | Closes: https://lore.kernel.org/oe-kbuild-all/202309270829.xHgTOMKw-lkp@intel.com/ So I updated the patch without these tags. > > V1: https://lore.kernel.org/all/ZRE4XvOOhz4HSOgR@fedora/ > > > > kernel/padata.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/kernel/padata.c b/kernel/padata.c > > index 222d60195de6..79d04a97ded6 100644 > > --- a/kernel/padata.c > > +++ b/kernel/padata.c > > @@ -1102,12 +1102,16 @@ EXPORT_SYMBOL(padata_alloc_shell); > > */ > > void padata_free_shell(struct padata_shell *ps) > > { > > + struct parallel_data *pd; > > + > > if (!ps) > > return; > > > > mutex_lock(&ps->pinst->lock); > > list_del(&ps->list); > > - padata_free_pd(rcu_dereference_protected(ps->pd, 1)); > > + pd = rcu_dereference_protected(ps->pd, 1); > > + if (refcount_dec_and_test(&pd->refcnt)) > > + padata_free_pd(rcu_dereference_protected(ps->pd, 1)); > > As Herbert points out, this version changes the code by > rcu-dereferencing pd twice. Usually previous acks are dropped when > introducing new changes, but you can have it back by only > rcu-dereferencing once and addressing the other comments above. Thanks for your and Herbert's acks, which were included in patch v4. I know Herbert has acked my patch from your email; however, I have not received Herbert's acknowledgment email, and I do not know why. > > > mutex_unlock(&ps->pinst->lock); > > > > kfree(ps); > > -- > > 2.40.0 > >