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 88205C19F2D for ; Tue, 9 Aug 2022 20:54:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229964AbiHIUyK (ORCPT ); Tue, 9 Aug 2022 16:54:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46894 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229950AbiHIUxm (ORCPT ); Tue, 9 Aug 2022 16:53:42 -0400 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 44E3D15A2B for ; Tue, 9 Aug 2022 13:53:41 -0700 (PDT) Received: by mail-pj1-x102c.google.com with SMTP id o5-20020a17090a3d4500b001ef76490983so123016pjf.2 for ; Tue, 09 Aug 2022 13:53:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc; bh=pJblVN/EwDKnGoYTvY52rorYjnKswwmvjLRNuq3g3VE=; b=GbUPKddyRcffK7GnxZeqqcUioCOBYjZYcND1JWvpTTanaun1D9fGTvEAbdn125PW6m JLjs5YyKKh7edLtHVT0tHekB/pNop76ht7souklms4QnoaKiHs8glUoRTRM+Mfo8T9Wd Q8JXLAja5U0d1nkYehhAvAfuKo06DjcO+uoxCK8jXyV1FA9g3aXQEBfaTLKZJ6FVL/Mt NMgBfRYESMHWHpBAQGqe86ARj9HVA94d7TsUE/YkyfA1kBd8DX8QSHykjK5j4xexTJPv k3mNOu14Dx9T3iSZbwK0WM2QonrbFR+wdYL0qCqooRcYs3zUHOlu/GhNspIACNbPZ6x3 ZDBA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc; bh=pJblVN/EwDKnGoYTvY52rorYjnKswwmvjLRNuq3g3VE=; b=pjn0WO+pRZ9TIZzSxE8dfxfdCd1kovXSTB7L9Q1+/2GumVrtl9MWBNLILQpXngbMSg ceVQSY8lkb+U9S2kqeqO1WXXB9+px3NAL2DtZZSH69fDBZhw0u/3A6pKXjOk/Nxq7l6y Y1kugRexenMuh2OOFMlqLXDRDmOyhdcTNeXbiPZrRSvpl6K/hdgxHciVXEqESRZs1Inf sEnI+E/yL2EECIilTL0CYnsO3Ng9JpcJ//sTXhhgosHTGABhOUbAJWdU5pKiEnY/LEQ5 2fLAsbsobglSAwdWD50V65DqA4kbfksmMMASBYjK0QlnF1p/UCk2AdEdF/DsyDnQal4a /edg== X-Gm-Message-State: ACgBeo160YqC2gr2wdpTDtjyCJbdL3uNRuivF+l/dSLX061giZPrMk8X n3pXkbrHu9tTEe91zG78boKgKg== X-Google-Smtp-Source: AA6agR5zPiBVnYt1kAUuxrAkMt0LXjWgm1wd+WLRJjf0RsoJ/oyZpNSqLwA3FNlryMJpO0oPIuNAIg== X-Received: by 2002:a17:902:eb8a:b0:16d:c75a:c40b with SMTP id q10-20020a170902eb8a00b0016dc75ac40bmr25435222plg.102.1660078420716; Tue, 09 Aug 2022 13:53:40 -0700 (PDT) Received: from google.com (7.104.168.34.bc.googleusercontent.com. [34.168.104.7]) by smtp.gmail.com with ESMTPSA id u8-20020a170902e5c800b00170a359eb0esm5711482plf.63.2022.08.09.13.53.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Aug 2022 13:53:40 -0700 (PDT) Date: Tue, 9 Aug 2022 20:53:36 +0000 From: Sean Christopherson To: Gavin Shan Cc: Florian Weimer , kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, maz@kernel.org, oliver.upton@linux.dev, andrew.jones@linux.dev, mathieu.desnoyers@efficios.com, yihyu@redhat.com, shan.gavin@gmail.com Subject: Re: [PATCH 2/2] KVM: selftests: Use getcpu() instead of sched_getcpu() in rseq_test Message-ID: References: <20220809060627.115847-1-gshan@redhat.com> <20220809060627.115847-3-gshan@redhat.com> <87y1vxncv1.fsf@oldenburg.str.redhat.com> <87mtcdnaxe.fsf@oldenburg.str.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Aug 09, 2022, Gavin Shan wrote: > On 8/9/22 5:17 PM, Florian Weimer wrote: > > * Florian Weimer: > > > > > * Gavin Shan: > > > > > > > sched_getcpu() is glibc dependent and it can simply return the CPU > > > > ID from the registered rseq information, as Florian Weimer pointed. > > > > In this case, it's pointless to compare the return value from > > > > sched_getcpu() and that fetched from the registered rseq information. > > > > > > > > Fix the issue by replacing sched_getcpu() with getcpu(), as Florian > > > > suggested. The comments are modified accordingly. > > > > > > Note that getcpu was added in glibc 2.29, so perhaps you need to perform > > > a direct system call? > > > > One more thing: syscall(__NR_getcpu) also has the advantage that it > > wouldn't have to be changed again if node IDs become available via rseq > > and getcpu is implemented using that. > > > > Thanks, > > Florian > > > > Thanks, Florian. It makes sense to me to use syscall(__NR_getcpu) in > next revision. Thanks for your quick review :) +1, and definitely add a comment to prevent future "cleanup".