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 X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68605C433EF for ; Sun, 17 Jun 2018 21:39:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0C5F3208A6 for ; Sun, 17 Jun 2018 21:39:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="O9bIH6Kv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0C5F3208A6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752835AbeFQVjz (ORCPT ); Sun, 17 Jun 2018 17:39:55 -0400 Received: from mail-wr0-f195.google.com ([209.85.128.195]:40398 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751340AbeFQVjy (ORCPT ); Sun, 17 Jun 2018 17:39:54 -0400 Received: by mail-wr0-f195.google.com with SMTP id l41-v6so14770431wre.7 for ; Sun, 17 Jun 2018 14:39:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version; bh=cT+QEify0UkXSsaDvFYBX3jCIe0gWqnD5E4FfeL5jxM=; b=O9bIH6Kv55t3ChKNdH2lyO0QgeIamgQ1uFVLAwwweQcNxNwddozme1l2EaCP/rRTuB /irOP0+OHYfatesCvlU6ktfBaJC1MQD4ugOgzQzfX0tlDpsF+28kksanJBdrwqe6lmeE 1PlRI8X+yMjd5l6BO/QxSrxaxieqElcRh0aDDNJIz8XMwh2i00LA0G/IMOwMdZhgEmU8 /kZYdbYchakQOgM0sK+9P8JfPj/f6obAohWKcQ7nCcmkB1GP/KehAU2x58B2CaQNwQwE 4SP0i1o0WzUiS8E49miLE3LgHbQk1pdB3mH/se96seBhCKQ1NlfuIVPhs2dQ9KRFeCgH E6jQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version; bh=cT+QEify0UkXSsaDvFYBX3jCIe0gWqnD5E4FfeL5jxM=; b=txhKSu4V9hcGEtVEcATXTaMV2tUkl8dIN++s6O6XBQCmCr+G0UGl9ULzSI1WyDLxyr h/NHAVEuDgu1XLcH4xtkGXQGP8BL8hYI3BVgxdbVJw7BxYpbW9v8HmtRLX6GzAhYLVrG hyHHbrgUVEJFoQKRQ96xwS4vN6V8gr4ON6uDELuDaRD0S7TfdYS1ufrS+35ImfMxfc+a q4gtdJdPkGUkVOdUuaObgjmFabRITjWqFmzGK4WxKA5JYWO3mjFfSx9GkcE3R6hHKIRl HSeyizvFZAyRhXwFFamrUmgjJVfWMzaGRXouBY+/YHmFybBwpw2FouhHjTN4562fQ/dJ v0TA== X-Gm-Message-State: APt69E0BuNrlGZXARlkJVoZyTTZvErVDTA78Q/Ld3I/oDnQMB7yy2ykW iB6HJs3+SZlFhvGI3mIrbDs= X-Google-Smtp-Source: ADUXVKJFiht8CcdtQE0KUhf3ICgFCnBVbw3VzWYKFSEbJwYMsf6MRTCnNAYvyEjpqQDHmPsoS1oF3g== X-Received: by 2002:adf:dc52:: with SMTP id m18-v6mr8653644wrj.84.1529271592834; Sun, 17 Jun 2018 14:39:52 -0700 (PDT) Received: from sf (trofi-1-pt.tunnel.tserv1.lon2.ipv6.he.net. [2001:470:1f1c:a0f::2]) by smtp.gmail.com with ESMTPSA id z14-v6sm5410928wma.11.2018.06.17.14.39.51 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sun, 17 Jun 2018 14:39:52 -0700 (PDT) Date: Sun, 17 Jun 2018 22:39:41 +0100 From: Sergei Trofimovich To: libc-alpha@sourceware.org, linux-kernel@vger.kernel.org, x86@kernel.org Cc: "H.J. Lu" Subject: Re: x86_64: movdqu rarely stores bad data (movdqu works fine). Kernel bug, fried CPU or glibc bug? Message-ID: <20180617223941.3e1e4973@sf> In-Reply-To: <20180616222250.618cecaa@sf> References: <20180616222250.618cecaa@sf> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_/0/IHR=MHGvQz/5AQoC5jeZa"; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Sig_/0/IHR=MHGvQz/5AQoC5jeZa Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Sat, 16 Jun 2018 22:22:50 +0100 Sergei Trofimovich wrote: > TL;DR: on master string/test-memmove glibc test fails on my machine > and I don't know why. Other tests work fine. > ... > This fails: > loop { > movdqu [src++],%xmm0 > movntdq %xmm0,[dst++] > } > sfence > This works: > loop { > movdqu [src++],%xmm0 > movdqu %xmm0,[dst++] > } > sfence > ... > If there is no obvious problems with glibc's memove() or my small test > what can I do to rule-out/pin-down hardware or kernel problem? Found the cause: bad RAM module. After I've tweaked test to allocate most of available physical RAM I've got fully reproducible failure. I unplugged RAM modules one by one and ran the test. That way I've nailed down to one bad chip. Removing single bad chip restored string/test-memmove test on this machine \o/ Sorry for the noise! --=20 Sergei --Sig_/0/IHR=MHGvQz/5AQoC5jeZa Content-Type: application/pgp-signature Content-Description: Цифровая подпись OpenPGP -----BEGIN PGP SIGNATURE----- iF0EARECAB0WIQSZKa0VG5avZRlY01hxoe52YR/zqgUCWybVHgAKCRBxoe52YR/z qq6fAJ9NIvK9XdOxNwHE20NPbDnGiUWY/ACfWHSy5bqY6Qpg3IIyibb5PfcaW1Q= =B3bY -----END PGP SIGNATURE----- --Sig_/0/IHR=MHGvQz/5AQoC5jeZa--