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=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable 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 15490C43613 for ; Mon, 24 Jun 2019 16:06:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E2C1120449 for ; Mon, 24 Jun 2019 16:06:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731587AbfFXQG0 (ORCPT ); Mon, 24 Jun 2019 12:06:26 -0400 Received: from mx2.suse.de ([195.135.220.15]:47560 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727082AbfFXQG0 (ORCPT ); Mon, 24 Jun 2019 12:06:26 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 85038AE21; Mon, 24 Jun 2019 16:06:24 +0000 (UTC) Subject: Re: [PATCH 09/12] xfs: refactor the ioend merging code To: Christoph Hellwig , "Darrick J . Wong" Cc: Damien Le Moal , Andreas Gruenbacher , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190624055253.31183-1-hch@lst.de> <20190624055253.31183-10-hch@lst.de> From: Nikolay Borisov Openpgp: preference=signencrypt Autocrypt: addr=nborisov@suse.com; prefer-encrypt=mutual; keydata= mQINBFiKBz4BEADNHZmqwhuN6EAzXj9SpPpH/nSSP8YgfwoOqwrP+JR4pIqRK0AWWeWCSwmZ T7g+RbfPFlmQp+EwFWOtABXlKC54zgSf+uulGwx5JAUFVUIRBmnHOYi/lUiE0yhpnb1KCA7f u/W+DkwGerXqhhe9TvQoGwgCKNfzFPZoM+gZrm+kWv03QLUCr210n4cwaCPJ0Nr9Z3c582xc bCUVbsjt7BN0CFa2BByulrx5xD9sDAYIqfLCcZetAqsTRGxM7LD0kh5WlKzOeAXj5r8DOrU2 GdZS33uKZI/kZJZVytSmZpswDsKhnGzRN1BANGP8sC+WD4eRXajOmNh2HL4P+meO1TlM3GLl EQd2shHFY0qjEo7wxKZI1RyZZ5AgJnSmehrPCyuIyVY210CbMaIKHUIsTqRgY5GaNME24w7h TyyVCy2qAM8fLJ4Vw5bycM/u5xfWm7gyTb9V1TkZ3o1MTrEsrcqFiRrBY94Rs0oQkZvunqia c+NprYSaOG1Cta14o94eMH271Kka/reEwSZkC7T+o9hZ4zi2CcLcY0DXj0qdId7vUKSJjEep c++s8ncFekh1MPhkOgNj8pk17OAESanmDwksmzh1j12lgA5lTFPrJeRNu6/isC2zyZhTwMWs k3LkcTa8ZXxh0RfWAqgx/ogKPk4ZxOXQEZetkEyTFghbRH2BIwARAQABtCNOaWtvbGF5IEJv cmlzb3YgPG5ib3Jpc292QHN1c2UuY29tPokCOAQTAQIAIgUCWIo48QIbAwYLCQgHAwIGFQgC CQoLBBYCAwECHgECF4AACgkQcb6CRuU/KFc0eg/9GLD3wTQz9iZHMFbjiqTCitD7B6dTLV1C ddZVlC8Hm/TophPts1bWZORAmYIihHHI1EIF19+bfIr46pvfTu0yFrJDLOADMDH+Ufzsfy2v HSqqWV/nOSWGXzh8bgg/ncLwrIdEwBQBN9SDS6aqsglagvwFD91UCg/TshLlRxD5BOnuzfzI Leyx2c6YmH7Oa1R4MX9Jo79SaKwdHt2yRN3SochVtxCyafDlZsE/efp21pMiaK1HoCOZTBp5 VzrIP85GATh18pN7YR9CuPxxN0V6IzT7IlhS4Jgj0NXh6vi1DlmKspr+FOevu4RVXqqcNTSS E2rycB2v6cttH21UUdu/0FtMBKh+rv8+yD49FxMYnTi1jwVzr208vDdRU2v7Ij/TxYt/v4O8 V+jNRKy5Fevca/1xroQBICXsNoFLr10X5IjmhAhqIH8Atpz/89ItS3+HWuE4BHB6RRLM0gy8 T7rN6ja+KegOGikp/VTwBlszhvfLhyoyjXI44Tf3oLSFM+8+qG3B7MNBHOt60CQlMkq0fGXd mm4xENl/SSeHsiomdveeq7cNGpHi6i6ntZK33XJLwvyf00PD7tip/GUj0Dic/ZUsoPSTF/mG EpuQiUZs8X2xjK/AS/l3wa4Kz2tlcOKSKpIpna7V1+CMNkNzaCOlbv7QwprAerKYywPCoOSC 7P25Ag0EWIoHPgEQAMiUqvRBZNvPvki34O/dcTodvLSyOmK/MMBDrzN8Cnk302XfnGlW/YAQ csMWISKKSpStc6tmD+2Y0z9WjyRqFr3EGfH1RXSv9Z1vmfPzU42jsdZn667UxrRcVQXUgoKg QYx055Q2FdUeaZSaivoIBD9WtJq/66UPXRRr4H/+Y5FaUZx+gWNGmBT6a0S/GQnHb9g3nonD jmDKGw+YO4P6aEMxyy3k9PstaoiyBXnzQASzdOi39BgWQuZfIQjN0aW+Dm8kOAfT5i/yk59h VV6v3NLHBjHVw9kHli3jwvsizIX9X2W8tb1SefaVxqvqO1132AO8V9CbE1DcVT8fzICvGi42 FoV/k0QOGwq+LmLf0t04Q0csEl+h69ZcqeBSQcIMm/Ir+NorfCr6HjrB6lW7giBkQl6hhomn l1mtDP6MTdbyYzEiBFcwQD4terc7S/8ELRRybWQHQp7sxQM/Lnuhs77MgY/e6c5AVWnMKd/z MKm4ru7A8+8gdHeydrRQSWDaVbfy3Hup0Ia76J9FaolnjB8YLUOJPdhI2vbvNCQ2ipxw3Y3c KhVIpGYqwdvFIiz0Fej7wnJICIrpJs/+XLQHyqcmERn3s/iWwBpeogrx2Lf8AGezqnv9woq7 OSoWlwXDJiUdaqPEB/HmGfqoRRN20jx+OOvuaBMPAPb+aKJyle8zABEBAAGJAh8EGAECAAkF AliKBz4CGwwACgkQcb6CRuU/KFdacg/+M3V3Ti9JYZEiIyVhqs+yHb6NMI1R0kkAmzsGQ1jU zSQUz9AVMR6T7v2fIETTT/f5Oout0+Hi9cY8uLpk8CWno9V9eR/B7Ifs2pAA8lh2nW43FFwp IDiSuDbH6oTLmiGCB206IvSuaQCp1fed8U6yuqGFcnf0ZpJm/sILG2ECdFK9RYnMIaeqlNQm iZicBY2lmlYFBEaMXHoy+K7nbOuizPWdUKoKHq+tmZ3iA+qL5s6Qlm4trH28/fPpFuOmgP8P K+7LpYLNSl1oQUr+WlqilPAuLcCo5Vdl7M7VFLMq4xxY/dY99aZx0ZJQYFx0w/6UkbDdFLzN upT7NIN68lZRucImffiWyN7CjH23X3Tni8bS9ubo7OON68NbPz1YIaYaHmnVQCjDyDXkQoKC R82Vf9mf5slj0Vlpf+/Wpsv/TH8X32ajva37oEQTkWNMsDxyw3aPSps6MaMafcN7k60y2Wk/ TCiLsRHFfMHFY6/lq/c0ZdOsGjgpIK0G0z6et9YU6MaPuKwNY4kBdjPNBwHreucrQVUdqRRm RcxmGC6ohvpqVGfhT48ZPZKZEWM+tZky0mO7bhZYxMXyVjBn4EoNTsXy1et9Y1dU3HVJ8fod 5UqrNrzIQFbdeM0/JqSLrtlTcXKJ7cYFa9ZM2AP7UIN9n1UWxq+OPY9YMOewVfYtL8M= Message-ID: Date: Mon, 24 Jun 2019 19:06:22 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190624055253.31183-10-hch@lst.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 24.06.19 г. 8:52 ч., Christoph Hellwig wrote: > Introduce two nicely abstracted helper, which can be moved to the > iomap code later. Also use list_pop and list_first_entry_or_null > to simplify the code a bit. > > Signed-off-by: Christoph Hellwig > --- > fs/xfs/xfs_aops.c | 66 ++++++++++++++++++++++++++--------------------- > 1 file changed, 36 insertions(+), 30 deletions(-) > > diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c > index acbd73976067..5d302ebe2a33 100644 > --- a/fs/xfs/xfs_aops.c > +++ b/fs/xfs/xfs_aops.c > @@ -121,6 +121,19 @@ xfs_destroy_ioend( > } > } > > +static void > +xfs_destroy_ioends( > + struct xfs_ioend *ioend, > + int error) > +{ > + struct list_head tmp; > + > + list_replace_init(&ioend->io_list, &tmp); > + xfs_destroy_ioend(ioend, error); > + while ((ioend = list_pop(&tmp, struct xfs_ioend, io_list))) > + xfs_destroy_ioend(ioend, error); nit: I'd prefer if the list_pop patch is right before this one since this is the first user of it. Additionally, I don't think list_pop is really a net-negative win in comparison to list_for_each_entry_safe here. In fact this "delete the list" would seems more idiomatic if implemented via list_for_each_entry_safe > +} > + > /* > * Fast and loose check if this write could update the on-disk inode size. > */ > @@ -173,7 +186,6 @@ xfs_end_ioend( > struct xfs_ioend *ioend) > { > unsigned int nofs_flag = memalloc_nofs_save(); > - struct list_head ioend_list; > struct xfs_inode *ip = XFS_I(ioend->io_inode); > xfs_off_t offset = ioend->io_offset; > size_t size = ioend->io_size; > @@ -207,16 +219,7 @@ xfs_end_ioend( > if (!error && xfs_ioend_is_append(ioend)) > error = xfs_setfilesize(ip, offset, size); > done: > - list_replace_init(&ioend->io_list, &ioend_list); > - xfs_destroy_ioend(ioend, error); > - > - while (!list_empty(&ioend_list)) { > - ioend = list_first_entry(&ioend_list, struct xfs_ioend, > - io_list); > - list_del_init(&ioend->io_list); > - xfs_destroy_ioend(ioend, error); > - } > - > + xfs_destroy_ioends(ioend, error); > memalloc_nofs_restore(nofs_flag); > } > > @@ -246,15 +249,16 @@ xfs_ioend_try_merge( > struct xfs_ioend *ioend, > struct list_head *more_ioends) > { > - struct xfs_ioend *next_ioend; > + struct xfs_ioend *next; > > - while (!list_empty(more_ioends)) { > - next_ioend = list_first_entry(more_ioends, struct xfs_ioend, > - io_list); > - if (!xfs_ioend_can_merge(ioend, next_ioend)) > + INIT_LIST_HEAD(&ioend->io_list); > + > + while ((next = list_first_entry_or_null(more_ioends, struct xfs_ioend, > + io_list))) { > + if (!xfs_ioend_can_merge(ioend, next)) > break; > - list_move_tail(&next_ioend->io_list, &ioend->io_list); > - ioend->io_size += next_ioend->io_size; > + list_move_tail(&next->io_list, &ioend->io_list); > + ioend->io_size += next->io_size; > } > } > > @@ -277,29 +281,31 @@ xfs_ioend_compare( > return 0; > } > > +static void > +xfs_sort_ioends( > + struct list_head *ioend_list) > +{ > + list_sort(NULL, ioend_list, xfs_ioend_compare); > +} > + > /* Finish all pending io completions. */ > void > xfs_end_io( > struct work_struct *work) > { > - struct xfs_inode *ip; > + struct xfs_inode *ip = > + container_of(work, struct xfs_inode, i_ioend_work); > struct xfs_ioend *ioend; > - struct list_head completion_list; > + struct list_head tmp; > unsigned long flags; > > - ip = container_of(work, struct xfs_inode, i_ioend_work); > - > spin_lock_irqsave(&ip->i_ioend_lock, flags); > - list_replace_init(&ip->i_ioend_list, &completion_list); > + list_replace_init(&ip->i_ioend_list, &tmp); > spin_unlock_irqrestore(&ip->i_ioend_lock, flags); > > - list_sort(NULL, &completion_list, xfs_ioend_compare); > - > - while (!list_empty(&completion_list)) { > - ioend = list_first_entry(&completion_list, struct xfs_ioend, > - io_list); > - list_del_init(&ioend->io_list); > - xfs_ioend_try_merge(ioend, &completion_list); > + xfs_sort_ioends(&tmp); > + while ((ioend = list_pop(&tmp, struct xfs_ioend, io_list))) { > + xfs_ioend_try_merge(ioend, &tmp); > xfs_end_ioend(ioend); Here again, tmp is a local copy that is immutable so using while() instead of list_for_each_entry_safe doesn't seem to be providing much. > } > } >