From patchwork Sat Jun 10 11:39:06 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Ritesh Harjani (IBM)" X-Patchwork-Id: 13274831 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 915F1C7EE45 for ; Sat, 10 Jun 2023 11:39:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231437AbjFJLji (ORCPT ); Sat, 10 Jun 2023 07:39:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234475AbjFJLjh (ORCPT ); Sat, 10 Jun 2023 07:39:37 -0400 Received: from mail-pl1-x62b.google.com (mail-pl1-x62b.google.com [IPv6:2607:f8b0:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DCECE1; Sat, 10 Jun 2023 04:39:36 -0700 (PDT) Received: by mail-pl1-x62b.google.com with SMTP id d9443c01a7336-1b065154b79so12848835ad.1; Sat, 10 Jun 2023 04:39:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1686397176; x=1688989176; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=EyPzAEGGPRspXW63qviQl5WaHG4admX+rKhNWOPMKZ4=; b=IPfqVdqC8nEEH9U/D/1dQLnY/PXx4eBDeA7Gf1SaGqYSLQGW27I0GT6y4wCS6ueIGQ iatCuRkPh5/Q1f6svIL8QD7qO2Rqv2Q+bIF7sA3dS+CX8vo1STBA5AtVKb0wfoOK42wR a75jVFsCQdPLBppKAhES+iIojW0u6gQ/DR7dmWhDN/Ff+1LHVe8Pm0wmxQ2i0X+McNP0 XXncXkzdXj4SmrfJjvnUXrw0swSCkw8ZwmQX+93/ERDmoGs4ZnQgEqbVk12OHpGywQA7 3Mk5Sh1tCg/AlDUxcVtFijTWXo7ptWMMbN/4qJr0TkMVcPHoihl1sr3QGaGQLlET9BT6 GauQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686397176; x=1688989176; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=EyPzAEGGPRspXW63qviQl5WaHG4admX+rKhNWOPMKZ4=; b=hh26NtUD5pHdKQkqkg6ZK9xfyd4tzWxiYFyBajilDr41jCHxVdvvfTsUgYezU/kNnJ 1zACcuvYoUjFwDICzuYSo74m1VEGTLWVu6/r0MExs7yZSlD+eUrtvbuAyd1mmfUD1YAR 0MlS+tDVR2YkVdCwxSd8bgX+layjq8FCvdwOGm9CwQPuXmHtXsu0CWg2pwvQ7Qp9EGhH Vbh1Wwcei+0zudpYmy+U/6sKCt9QAcwJVupgLx1E+H8DUcytMdzRF0GVdcj+UrFZQZzo f1NpAzlhzP7iSLroqqsTJqhicZmEX6w9P6AHtKCoc3G1iLp9JNHSJivgey2rxiEjMnnZ dOYw== X-Gm-Message-State: AC+VfDyAubSHwpTaDADVEb5lM/O6QTlwcDclPD/ItQYkwcWwsA5hBxcK icRrK7QmGAeXNvkb/INGAu2X6SvYkys= X-Google-Smtp-Source: ACHHUZ4+1uFpqiGwuS4o3sdBdHVs98XMNBhtbt3aD85AiRfAL5m21n35GTBRi4VdVzQj/Q0S0TVkqw== X-Received: by 2002:a17:902:d486:b0:1a6:9762:6eed with SMTP id c6-20020a170902d48600b001a697626eedmr1895866plg.22.1686397175689; Sat, 10 Jun 2023 04:39:35 -0700 (PDT) Received: from dw-tp.ihost.com ([49.207.220.159]) by smtp.gmail.com with ESMTPSA id n10-20020a170902e54a00b001aaf5dcd762sm4753698plf.214.2023.06.10.04.39.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 10 Jun 2023 04:39:35 -0700 (PDT) From: "Ritesh Harjani (IBM)" To: linux-xfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, Christoph Hellwig , "Darrick J. Wong" , Matthew Wilcox , Dave Chinner , Brian Foster , Andreas Gruenbacher , Ojaswin Mujoo , Disha Goel , "Ritesh Harjani (IBM)" , Christoph Hellwig Subject: [PATCHv9 5/6] iomap: Allocate ifs in ->write_begin() early Date: Sat, 10 Jun 2023 17:09:06 +0530 Message-Id: X-Mailer: git-send-email 2.40.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org We dont need to allocate an ifs in ->write_begin() for writes where the position and length completely overlap with the given folio. Therefore, such cases are skipped. Currently when the folio is uptodate, we only allocate ifs at writeback time (in iomap_writepage_map()). This is ok until now, but when we are going to add support for per-block dirty state bitmap in ifs, this could cause some performance degradation. The reason is that if we don't allocate ifs during ->write_begin(), then we will never mark the necessary dirty bits in ->write_end() call. And we will have to mark all the bits as dirty at the writeback time, that could cause the same write amplification and performance problems as it is now. Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Ritesh Harjani (IBM) --- fs/iomap/buffered-io.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 1261f26479af..c6dcb0f0d22f 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -567,14 +567,23 @@ static int __iomap_write_begin(const struct iomap_iter *iter, loff_t pos, size_t from = offset_in_folio(folio, pos), to = from + len; size_t poff, plen; - if (folio_test_uptodate(folio)) + /* + * If the write completely overlaps the current folio, then + * entire folio will be dirtied so there is no need for + * per-block state tracking structures to be attached to this folio. + */ + if (pos <= folio_pos(folio) && + pos + len >= folio_pos(folio) + folio_size(folio)) return 0; - folio_clear_error(folio); ifs = iomap_ifs_alloc(iter->inode, folio, iter->flags); if ((iter->flags & IOMAP_NOWAIT) && !ifs && nr_blocks > 1) return -EAGAIN; + if (folio_test_uptodate(folio)) + return 0; + folio_clear_error(folio); + do { iomap_adjust_read_range(iter->inode, folio, &block_start, block_end - block_start, &poff, &plen);