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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 181E4C432BE for ; Sat, 28 Aug 2021 22:21:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E42FB60E93 for ; Sat, 28 Aug 2021 22:21:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232819AbhH1WWA (ORCPT ); Sat, 28 Aug 2021 18:22:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230253AbhH1WV7 (ORCPT ); Sat, 28 Aug 2021 18:21:59 -0400 Received: from mail-pj1-x102f.google.com (mail-pj1-x102f.google.com [IPv6:2607:f8b0:4864:20::102f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03579C061756; Sat, 28 Aug 2021 15:21:09 -0700 (PDT) Received: by mail-pj1-x102f.google.com with SMTP id ot2-20020a17090b3b4200b0019127f8ed87so9974085pjb.1; Sat, 28 Aug 2021 15:21:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=r6Li8Xzq3GZpRD4yRN9H4niugZXTcIcOHoay7QTmmqc=; b=i199VmbLftiUhfm5w9TMwG+4Zf15RGuEdy9vUNnpXVkRH8IKECoWxujWMKUM6b84Xj vJIt4AyP193AT6JMaZqM2108oM703qbcQXepEStj+SyN34yY5kAbjEpMOLGRfvEnhLwD Yw/zR35PCA1ul7az8DVV6WxmaAmrVxAjUhxlMJYrp5LwHhJhncGjh+kEO6C+xUOwIYIK HGZRfwPHEz91HYwm0f0LbEqHi8eFfah3zdtLG65KiyNGXMieukAjYa8GmhDCRYzKMtkJ a/N3lSlUJEK/v4Iu5eztYUtd5dIYRDNtlqGhxh5lAkVeMe1c5VFf3McWOZ9uFYYtGopY f0iQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=r6Li8Xzq3GZpRD4yRN9H4niugZXTcIcOHoay7QTmmqc=; b=e4hUbu3fbwQM2zstgIZvxxBCSsQe2x77fe060r4oGQon99KQn2VU21iWWDOlt6MVIx M5RvzYFHw9vzwS0SBdZFAcetMMaz8tkbekpxu/eAoVTAOP9L1JVrxDeNuu3ODFdVeWOh F419tbrWRnxiY68Rr16N+HCFtuL9ile0QLN1uUKziZENHful4ZMzxJR3Q2khRwG54rET XLLtJzeFAqGZFOWBsZJ0sDTdc8reafTzUQ45tCC+NnnHEVrYkgMngq3yFL5lSkmoqZtU gu1jLqFrUqSkDBt7MSr1L2aLUQfJBiwaTPrmiaRbhIE1gQQw/ZJmPlLT6tPkAQvsbWjA tFDg== X-Gm-Message-State: AOAM530jCRaylwgaPPnMG/7QPh3xWPzMr1z4LH1CukAYDHpsszy87mmM 5oJniNSedg5l4oQlE2WYLXUVASTcoh8FZd5G6LY= X-Google-Smtp-Source: ABdhPJz5Ffz08GjVQcWFqoF1crFop4nyJwqZjDMwOjo601G/TSenqG6Qmt+G6ELqJMjIOGz8touEqFLJCNdEjf1f3Wg= X-Received: by 2002:a17:90a:eb0d:: with SMTP id j13mr18377241pjz.163.1630189268569; Sat, 28 Aug 2021 15:21:08 -0700 (PDT) MIME-Version: 1.0 References: <20210827232246.GA1668365@agluck-desk2.amr.corp.intel.com> <87r1edgs2w.ffs@tglx> In-Reply-To: From: Tony Luck Date: Sat, 28 Aug 2021 15:20:58 -0700 Message-ID: Subject: Re: [PATCH v7 05/19] iov_iter: Introduce fault_in_iov_iter_writeable To: Al Viro Cc: Thomas Gleixner , Linus Torvalds , Andreas Gruenbacher , Christoph Hellwig , "Darrick J. Wong" , Jan Kara , Matthew Wilcox , cluster-devel , linux-fsdevel , Linux Kernel Mailing List , ocfs2-devel@oss.oracle.com, Borislav Petkov , X86-ML Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sat, Aug 28, 2021 at 3:12 PM Al Viro wrote: > BTW, is #MC triggered on stored to a poisoned cacheline? Existence of CLZERO > would seem to argue against that... No #MC on stores. Just on loads. Note that you can't clear poison state with a series of small writes to the cache line. But a single 64-byte store might do it (architects didn't want to guarantee that it would work when I asked about avx512 stores to clear poison many years ago). -Tony