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 picard.linux.it (picard.linux.it [213.254.12.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 528B4C25B0E for ; Tue, 16 Aug 2022 23:00:37 +0000 (UTC) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id 0C4B23C9AC7 for ; Wed, 17 Aug 2022 01:00:35 +0200 (CEST) Received: from in-6.smtp.seeweb.it (in-6.smtp.seeweb.it [IPv6:2001:4b78:1:20::6]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (No client certificate requested) by picard.linux.it (Postfix) with ESMTPS id C3E8E3C91D2 for ; Wed, 17 Aug 2022 01:00:21 +0200 (CEST) Received: from mail-vs1-xe29.google.com (mail-vs1-xe29.google.com [IPv6:2607:f8b0:4864:20::e29]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by in-6.smtp.seeweb.it (Postfix) with ESMTPS id 722211400537 for ; Wed, 17 Aug 2022 01:00:19 +0200 (CEST) Received: by mail-vs1-xe29.google.com with SMTP id m67so11607320vsc.12 for ; Tue, 16 Aug 2022 16:00:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc; bh=6cqpYws9Kkr5SsRvOdPN2iATfm3cKMuT/gfwcTCKA7A=; b=WzSSjhCUnOZk+Eq/419hEzZRqdeBNzCWZBXgvx6KXahuglmr9ebvv96NmZYEtHxyNJ cTlH5FWQ371zsdUUaiky2yQNa9BLZeOpAE1z0wu48QhuWzQqinY/LH+Qzu4oXRbEotaN +YD809o0WEhEH+a7vhYr7k3HM0W/8NIGgoAd3olk3yTQ4hzQw6JO0yPrqysvHiAdr+zA YbSzxldOGbrOyQr4puR95JlsTAHZ48eSnW/aIbPeRfu3Cv+xSVuzb8E3mDvR4LW84I6s TSFLWmegTXjjOYaHCOQ0fL2e/+ZQD1QjSMPE6y+RiNhenXfRQ6K920SCpUAOjhmRMBXc f3Rw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc; bh=6cqpYws9Kkr5SsRvOdPN2iATfm3cKMuT/gfwcTCKA7A=; b=cNJQEIGY2apoxD0dRFGQOl9JR6OJSCXqtsd902a+u1bYAW5lGYXCJsyQkmj3PuqfLs A+6YhL6FbVm8bssBEivGdaRRaoNND11YFdkOYJiiddVJfxhnUHJKoJ1WplbjDJzJGkGy 6jWCJi9LRP1WcRXXiGYscPveOx2UnZa9JXFVvptzJy9OEiJK8Yyts/3yC0Czsor4FBLi SdCqLvLO07qhLoy3GeNpAn3qoUZxj20Wh7AHpche1sa8c+GiTZdiC6AWGDGskELhC4Zz rgOrAOR7W8Q6fPlFRsUFvBiqKDuh49dpye0H0Zj9sGbttwukp2yMhZuro4nQOgrgx0B9 CAoA== X-Gm-Message-State: ACgBeo1MaxsBqJA6SauQpk3H8EBx+eb2oqGBbL4N1B+tPJHsxo0dvs0m /675TmmRjJGeIcuHKyoUm4CGEUEOjqSaUdvZt7PbmA== X-Google-Smtp-Source: AA6agR6ed0y7RcyA02HPD9otW/FbtDBAxh9gbj6b+Y5WMoXFf6fiuGPqH+GfgXPRdxpTqNcpNX9wRb2aFLtOZldzD5U= X-Received: by 2002:a67:b243:0:b0:38c:2d4e:78b4 with SMTP id s3-20020a67b243000000b0038c2d4e78b4mr2505159vsh.73.1660690818027; Tue, 16 Aug 2022 16:00:18 -0700 (PDT) MIME-Version: 1.0 References: <20220712173921.2623135-1-edliaw@google.com> In-Reply-To: Date: Tue, 16 Aug 2022 16:00:07 -0700 Message-ID: To: Petr Vorel X-Virus-Scanned: clamav-milter 0.102.4 at in-6.smtp.seeweb.it X-Virus-Status: Clean Subject: Re: [LTP] [PATCH v1] syscalls/signal06: add volatile to loop variable X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Edward Liaw via ltp Reply-To: Edward Liaw Cc: kernel-team@android.com, ltp@lists.linux.it Content-Type: multipart/mixed; boundary="===============1264159511==" Errors-To: ltp-bounces+ltp=archiver.kernel.org@lists.linux.it Sender: "ltp" --===============1264159511== Content-Type: multipart/alternative; boundary="0000000000004aff6605e663b616" --0000000000004aff6605e663b616 Content-Type: text/plain; charset="UTF-8" We are currently building with clang 14.0.6. I haven't filed a bug report with llvm, will work on doing that. On Tue, Aug 16, 2022 at 5:43 AM Petr Vorel wrote: > Hi Edward, > > > Hi! > > > I think I finally understand what you mean by this now; it is rather > > > strange that the volatility of D does not protect loop from being > > > optimized away by the compiler. I don't have a good explanation as to > > > why it's happening but I'm not sure how to evaluate what's going on > > > either. Should I do anything to move this patch forward? > > > It all boils down if we want to work around something that looks like a > > compiler bug in tests or not. I would be inclined not to do so since LTP > > was littered with quite a lot of workarounds for glibc/compiler bugs and > > we spend quite some time cleaning that mess up. But in this case I can > > agree that this is a borderland issue so I'm not strongly against that > > either. > > Edward, which which clang version requires it? It'd be nice to document > it, so > that it can be removed in the future. > Is there any bug report for it? > > Kind regards, > Petr > --0000000000004aff6605e663b616 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
We are currently building with=C2=A0clang 14.0.6.=C2=A0 I = haven't filed a bug report with llvm, will work on doing that.
On Tue, A= ug 16, 2022 at 5:43 AM Petr Vorel <pvorel@suse.cz> wrote:
Hi Edward,

> Hi!
> > I think I finally understand what you mean by this now; it is rat= her
> > strange that the volatility of D does not protect loop from being=
> > optimized away by the compiler.=C2=A0 I don't have a good exp= lanation as to
> > why it's happening but I'm not sure how to evaluate what&= #39;s going on
> > either.=C2=A0 Should I do anything to move this patch forward?
> It all boils down if we want to work around something that looks like = a
> compiler bug in tests or not. I would be inclined not to do so since L= TP
> was littered with quite a lot of workarounds for glibc/compiler bugs a= nd
> we spend quite some time cleaning that mess up. But in this case I can=
> agree that this is a borderland issue so I'm not strongly against = that
> either.

Edward, which which clang version requires it? It'd be nice to document= it, so
that it can be removed in the future.
Is there any bug report for it?

Kind regards,
Petr
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