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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53EF8C433EF for ; Mon, 23 May 2022 20:56:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BEEC76B0073; Mon, 23 May 2022 16:56:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B76D76B0075; Mon, 23 May 2022 16:56:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A1A076B0078; Mon, 23 May 2022 16:56:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 8E63C6B0073 for ; Mon, 23 May 2022 16:56:50 -0400 (EDT) Received: from smtpin31.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 55133344D4 for ; Mon, 23 May 2022 20:56:50 +0000 (UTC) X-FDA: 79498216980.31.58B346B Received: from mail-vk1-f177.google.com (mail-vk1-f177.google.com [209.85.221.177]) by imf09.hostedemail.com (Postfix) with ESMTP id B295614001C for ; Mon, 23 May 2022 20:56:37 +0000 (UTC) Received: by mail-vk1-f177.google.com with SMTP id i25so2704531vkr.8 for ; Mon, 23 May 2022 13:56:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=zzdR40l4t49BhcKjBeDt6RD1hRuvcftxidhZX+LxdXA=; b=DZdJON7t3PwgCrrmoucnoFvSfX5CB986DtveajogrvKr6pbaUxLeSsuyQgxal0XNhS KtUMABkOtZddGLrKTjmkE65iB7IBOMFLTOkO0T+JtTANcIxtK2pw75L4/fulZM/sIv3h 9w7OjUket0wgm0eyX2hnQquy+pbw3X7FBf0cdOz4/mr3FAKvSrbXpXxx4Px8rX0wzKxu FK6Jc3VfmpkY39qs5xYc4jSO+jajCnvH6nUZ8z49/7le/3VS/Ut/yN2jQrVCSxGc1Eo/ u/QcFtp7hLmI/TtYQlEYEIeQLjQExhL4r5PyZsLRMj4OYJECPC3Edhqg9azGHa3WKDLS wRBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=zzdR40l4t49BhcKjBeDt6RD1hRuvcftxidhZX+LxdXA=; b=7S8aFZrITJfBQB76t/W7OdzE3peLKKwJ42ylD+S+PjpLLtNLxGj+Sllsh5HMtF1Ypn ZzEpnyuQjph7fmu3eTizXhKTs+jhEvzYiofr1u8+YegwQwbfL6XR4LGmQpwWJ6Kvsz4i dL6e/1ZJhrjCmrRV3lxhFj9LuozBHxOtOo/rf0eZSQ3GKj0KBDFqulXfBSpafpcKbG3q iSBRiqeBM5KX+JUm8bSz++Eo6I10kX1yvephM4TcKkKn3hAecfQNMXuFNhKsudJPkvPA 1j1+uabKZhzqNZ6/pE/tNpvtKaYk9Ear4f7dk6/VOsk7J0ktM0zKp+OqcSpIFbjAtLqA 0pdQ== X-Gm-Message-State: AOAM533fzvX1rAkSci77Qkd7/sZxkrWGkOZMc/tIjKXejk34vA/uUYG0 7To6qfbOyT4Mw22W2wb1/LW8N6gbXEzY+YFclhmFFg== X-Google-Smtp-Source: ABdhPJwGoP2jfrDhtWQgFx4bSOEJyIfQRib61SYaE0aRLL2I/I+lfsoRwqrX0NDaMtQIQfBFPy0Uz3uIFeL9+8Ja5x8= X-Received: by 2002:a1f:ec45:0:b0:34e:6cdc:334e with SMTP id k66-20020a1fec45000000b0034e6cdc334emr8914633vkh.26.1653339408905; Mon, 23 May 2022 13:56:48 -0700 (PDT) MIME-Version: 1.0 References: <20220507015646.5377-1-hdanton@sina.com> In-Reply-To: From: Yu Zhao Date: Mon, 23 May 2022 14:56:12 -0600 Message-ID: Subject: Re: Alpha: rare random memory corruption/segfault in user space bisected To: Michael Cree Cc: Linux-MM , linux-kernel , Hillf Danton , Joonsoo Kim Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: ochyimbcsrifox3zy5w7uh6yuooks5pt X-Rspam-User: Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=DZdJON7t; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf09.hostedemail.com: domain of yuzhao@google.com designates 209.85.221.177 as permitted sender) smtp.mailfrom=yuzhao@google.com X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: B295614001C X-HE-Tag: 1653339397-390339 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, May 11, 2022 at 2:37 PM Michael Cree wrote: > > On Sat, May 07, 2022 at 11:27:15AM -0700, Yu Zhao wrote: > > On Fri, May 6, 2022 at 6:57 PM Hillf Danton wrote: > > > > > > On Sat, 7 May 2022 09:21:25 +1200 Michael Cree wrote: > > > > Alpha kernel has been exhibiting rare and random memory > > > > corruptions/segaults in user space since the 5.9.y kernel. First seen > > > > on the Debian Ports build daemon when running 5.10.y kernel resulting > > > > in the occasional (one or two a day) build failures with gcc ICEs either > > > > due to self detected corrupt memory structures or segfaults. Have been > > > > running 5.8.y kernel without such problems for over six months. > > > > > > > > Tried bisecting last year but went off track with incorrect good/bad > > > > determinations due to rare nature of bug. After trying a 5.16.y kernel > > > > early this year and seen the bug is still present retried the bisection > > > > and have got to: > > > > > > > > aae466b0052e1888edd1d7f473d4310d64936196 is the first bad commit > > > > commit aae466b0052e1888edd1d7f473d4310d64936196 > > > > Author: Joonsoo Kim > > > > Date: Tue Aug 11 18:30:50 2020 -0700 > > > > > > > > mm/swap: implement workingset detection for anonymous LRU > > > > This commit seems innocent to me. While not ruling out anything, i.e., > > this commit, compiler, qemu, userspace itself, etc., my wild guess is > > the problem is memory barrier related. Two lock/unlock pairs, which > > imply two full barriers, were removed. This is not a small deal on > > Alpha, since it imposes no constraints on cache coherency, AFAIK. > > > > Can you please try the attached patch on top of this commit? Thanks! > > Thanks, I have that running now for a day without any problem showing > up, but that's not long enough to be sure it has fixed the problem. Will > get back to you after another day or two of testing. Any luck? Thanks!