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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 54F0EC47084 for ; Mon, 24 May 2021 11:57:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2B0CE61370 for ; Mon, 24 May 2021 11:57:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232676AbhEXL7V (ORCPT ); Mon, 24 May 2021 07:59:21 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:24072 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232110AbhEXL7U (ORCPT ); Mon, 24 May 2021 07:59:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621857472; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=gBjUa2nRpQaREb20KJBh+QSbceI06cH7v6nabFDej5s=; b=StK7uUhurmzdLvQmg8abBkZQXL6P7w4FBezyaRhNlW/tPsAPZCSWHUdjW9bd1nc/crzGTV uzufzjQq7DeBEI9ILhXX2gkCeHIJWawS1N5rhWnZJH3gx7PNUr+LvvkEPmhbfEa908eBY6 wOWjLGFsoznNKxJiSBngW1NUbtVCGtg= Received: from mail-qt1-f199.google.com (mail-qt1-f199.google.com [209.85.160.199]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-197-dtULvetwPPSQPIAdmJGr4g-1; Mon, 24 May 2021 07:57:50 -0400 X-MC-Unique: dtULvetwPPSQPIAdmJGr4g-1 Received: by mail-qt1-f199.google.com with SMTP id j12-20020ac8550c0000b02901dae492d1f2so23761940qtq.0 for ; Mon, 24 May 2021 04:57:50 -0700 (PDT) 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:references :mime-version:content-disposition:in-reply-to; bh=gBjUa2nRpQaREb20KJBh+QSbceI06cH7v6nabFDej5s=; b=EWYHpdTp/WFhEWHskPWju1I+0PJa4rXiaMaqyLi5x5hcIuVg1BXzd3bv9ZipW+cKGK HaA9LKO/MexYn1qzQ9levpMnOiGJCm1tk4g/k08hYayAK6uTQ2ctPXUAftAT+ctwKWlS jpE9vbzO4u60lYK2O/yN4QR9mqCzsMiEw9mtp9BiiRUOoni+bs7tkAiUYR6V/zCpTRHM ebepKWDUzzWLWqlikJ3YjJa5JHtSLmn8ZeJMuX/Cp7cS4gUL4b2rpEr1Bj39mYL5p1yi XjwczOk3qcDlhJE56LyizDB7qmiK3918T88z/GsujhmMWG4AcggbCBCHJothJzCdmHds EtzA== X-Gm-Message-State: AOAM5302SiprHdfjkRZiciLy5IPPdOHevdHlfkFH7V3BqI5jq+iTzD3R iPtk88GViTFfywKkhcOK6Lewnsa9wWB9zFpsaHaBaU+5lePW180Z5RpSwum1xbEzdv/+bOeNQ5r tmAY5mC2zshOxOXl/0VUITsCF6A== X-Received: by 2002:ac8:4b65:: with SMTP id g5mr26923004qts.99.1621857470374; Mon, 24 May 2021 04:57:50 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyBCBqseIt59+zUqt1o7nZHyGZvBbkwn5pbUOW6+M5xCIus8gENm21ONFHmm0JTEzJubX+y6A== X-Received: by 2002:ac8:4b65:: with SMTP id g5mr26922994qts.99.1621857470212; Mon, 24 May 2021 04:57:50 -0700 (PDT) Received: from bfoster ([98.216.211.229]) by smtp.gmail.com with ESMTPSA id l10sm10482883qtn.28.2021.05.24.04.57.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 May 2021 04:57:49 -0700 (PDT) Date: Mon, 24 May 2021 07:57:48 -0400 From: Brian Foster To: Ming Lei Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v3 1/3] iomap: resched ioend completion when in non-atomic context Message-ID: References: <20210517171722.1266878-1-bfoster@redhat.com> <20210517171722.1266878-2-bfoster@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: linux-fsdevel@vger.kernel.org On Sat, May 22, 2021 at 03:45:11PM +0800, Ming Lei wrote: > On Mon, May 17, 2021 at 01:17:20PM -0400, Brian Foster wrote: > > The iomap ioend mechanism has the ability to construct very large, > > contiguous bios and/or bio chains. This has been reported to lead to > > BTW, it is actually wrong to complete a large bio chains in > iomap_finish_ioend(), which may risk in bio allocation deadlock, cause > bio_alloc_bioset() relies on bio submission to make forward progress. But > it becomes not true when all chained bios are freed just after the whole > ioend is done since all chained bios(except for the one embedded in ioend) > are allocated from same bioset(fs_bio_set). > Interesting. Do you have a reproducer (or error report) for this? Is it addressed by the next patch, or are further changes required? Brian > > Thanks, > Ming >