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 5AD46C433EF for ; Fri, 15 Jul 2022 17:54:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229680AbiGORys (ORCPT ); Fri, 15 Jul 2022 13:54:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56896 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229481AbiGORyr (ORCPT ); Fri, 15 Jul 2022 13:54:47 -0400 Received: from out2.migadu.com (out2.migadu.com [188.165.223.204]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 70D7E33375; Fri, 15 Jul 2022 10:54:46 -0700 (PDT) Date: Fri, 15 Jul 2022 10:54:39 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1657907684; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6uT+2TT9W95VXeCHWDiSSD2luBuxQhau1FLF5w4a/0c=; b=MZyZiEOxH6F+9U95uSCMXEsHLFlHo3bfeOfGDlmL7fIJyMrAy0ahKSFopt1ppvQMgec/PO HZaTUvdsJ4GHoFKSl5kWqwYBQIf9EfeDYAQ3ieyja5nsH97q6pAEK9LYHuASLS0u6C0JpU JQEWtQRluVwP2j2cDeHhcbonQDaPZvE= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Roman Gushchin To: Michal =?iso-8859-1?Q?Koutn=FD?= Cc: axboe@kernel.dk, asml.silence@gmail.com, fam.zheng@bytedance.com, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, usama.arif@bytedance.com Subject: Re: [PATCH] io_uring: Don't require reinitable percpu_ref Message-ID: References: <8a9adb78-d9bb-a511-e4c1-c94cca392c9b@kernel.dk> <20220715174501.25216-1-mkoutny@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220715174501.25216-1-mkoutny@suse.com> X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Fri, Jul 15, 2022 at 07:45:01PM +0200, Michal Koutny wrote: > The commit 8bb649ee1da3 ("io_uring: remove ring quiesce for > io_uring_register") removed the worklow relying on reinit/resurrection > of the percpu_ref, hence, initialization with that requested is a relic. > > This is based on code review, this causes no real bug (and theoretically > can't). Technically it's a revert of commit 214828962dea ("io_uring: > initialize percpu refcounters using PERCU_REF_ALLOW_REINIT") but since > the flag omission is now justified, I'm not making this a revert. > > Fixes: 8bb649ee1da3 ("io_uring: remove ring quiesce for io_uring_register") > Signed-off-by: Michal Koutný Acked-by: Roman Gushchin Thanks!