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 D651BC43334 for ; Tue, 28 Jun 2022 09:23:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229935AbiF1JXE (ORCPT ); Tue, 28 Jun 2022 05:23:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344236AbiF1JWi (ORCPT ); Tue, 28 Jun 2022 05:22:38 -0400 Received: from mail-pl1-x636.google.com (mail-pl1-x636.google.com [IPv6:2607:f8b0:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 591611D314; Tue, 28 Jun 2022 02:22:37 -0700 (PDT) Received: by mail-pl1-x636.google.com with SMTP id n10so10587417plp.0; Tue, 28 Jun 2022 02:22:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=/RPscv3+8g8rx4jXo23oMEeXPiuNo7BXGYwm+0AjXxs=; b=To1tuJ6ezfSPRvfvYleOSb9lKKOhueWfZvhziXTEgCM9PUQE9mQ/xhT/GQKDwAx3+K VCwO+26BUmVeT7tjCm709OpoNluVA5TQnQMiEBOnZWK6u0h7/2MQKkzXLs/QTBPtLd+t uaEv/5/AD3aMBX+7rY78FIuqtsaMYfGOxtLmBiFL7mE3st9gwwEYdkaho0GnDCcCS+C6 4iEp8WxQDcPWTMDrt/QPMRtV+Nsnq3jb5UHhTTcpJedWllF567kplSbpUcwnVLjnZnAa /5C8nTucMrmiuELtf9puqfjdHfigFReLoMkmJ6zo4PcDCEvdsypTDDGCHRq1camco5J+ ++lg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition :content-transfer-encoding:in-reply-to; bh=/RPscv3+8g8rx4jXo23oMEeXPiuNo7BXGYwm+0AjXxs=; b=u82EjJlCCIcvKHmEVtCSWd6+mXAy1iqPxgQKMvYluUpYtFi6PmtvolOQkWCxY0vAI/ YLUBlP6gIc7FhqO0M2PvcG5v9I/YgpjXtLbXOqXwgnVLyq6cBbzB0/9uZTpR+Mgnpdew zE3fu/dshLAm9jjiXIFIB5RvpFhgFGP8btvfa5jjIRxlZ+FhFSyGtpcFL1Nn0RHYIU8o hOpMWqyKfPxXsaHQt0oUnIA2D7p6+Kr2kJZOSzvk8/yReIsJuWaenPf/kMJbGFq4Duc+ pGn3IQBNgeFWg06r9jBvEPhNlLwu/jT42or8Oy1tpYrpR8M77HmuTlf8QYSB5AfVHm1v ZVsA== X-Gm-Message-State: AJIora/RqHoZziuODpDtdhb1mxlvzz0+/MGni9AIjxSRm3i0vIJR5nBV ffN1UlIVP5BEM/ErWQxRBxU= X-Google-Smtp-Source: AGRyM1uO4shhe2Mc2XBAl9CUgG5Vgh4gk8x1TLLyeTMM88uYJk5piLi8VUIAziOH8v19ngumbUBM/A== X-Received: by 2002:a17:90b:1e0e:b0:1ec:b2a6:c9d0 with SMTP id pg14-20020a17090b1e0e00b001ecb2a6c9d0mr26659992pjb.230.1656408156659; Tue, 28 Jun 2022 02:22:36 -0700 (PDT) Received: from localhost ([121.167.227.144]) by smtp.gmail.com with ESMTPSA id p9-20020a1709026b8900b0016372486febsm8688757plk.297.2022.06.28.02.22.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jun 2022 02:22:36 -0700 (PDT) Sender: Tejun Heo Date: Tue, 28 Jun 2022 18:22:33 +0900 From: Tejun Heo To: Michal =?iso-8859-1?Q?Koutn=FD?= Cc: Vasily Averin , Roman Gushchin , Shakeel Butt , Michal Hocko , Zefan Li , Johannes Weiner , kernel@openvz.org, linux-kernel@vger.kernel.org, Andrew Morton , linux-mm@kvack.org, Vlastimil Babka , Muchun Song , cgroups@vger.kernel.org Subject: Re: [PATCH cgroup] cgroup: set the correct return code if hierarchy limits are reached Message-ID: References: <186d5b5b-a082-3814-9963-bf57dfe08511@openvz.org> <17916824-ba97-68ba-8166-9402d5f4440c@openvz.org> <20220628091648.GA12249@blackbody.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220628091648.GA12249@blackbody.suse.cz> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 28, 2022 at 11:16:48AM +0200, Michal Koutný wrote: > The mkdir(2) manpage doesn't list EAGAIN at all. ENOSPC makes better > sense here. (And I suspect the dependency on this particular value won't > be very wide spread.) Given how we use these system calls as triggers for random kernel operations, I don't think adhering to posix standard is necessary or possible. Using an error code which isn't listed in the man page isn't particularly high in the list of discrepancies. Again, I'm not against changing it but I'd like to see better rationales. On one side, we have "it's been this way for a long time and there's nothing particularly broken about it". I'm not sure the arguments we have for the other side is strong enough yet. Thanks. -- tejun