From patchwork Tue Dec 15 00:20:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 11973407 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 4119DC2BBCF for ; Tue, 15 Dec 2020 00:25:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DDEE22273 for ; Tue, 15 Dec 2020 00:25:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728333AbgLOAY6 (ORCPT ); Mon, 14 Dec 2020 19:24:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53446 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727514AbgLOAYq (ORCPT ); Mon, 14 Dec 2020 19:24:46 -0500 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 74062C0617A6; Mon, 14 Dec 2020 16:24:06 -0800 (PST) Received: by mail-wm1-x344.google.com with SMTP id g25so9987084wmh.1; Mon, 14 Dec 2020 16:24:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=D7uupKi2lTHg1nTREBYfC4U7HbsUj926sgl3xgaqTd0=; b=P81A9Xdxqm6t1KFSSYwxpIM9EzQWTzR8Kz1eIjcTpt9oDQteS1+WmwytiySg9Ve3ck NH3x0eCT2MFsM6i7mpTaRmDkUKmx5yR84cDkT/K6YRM1+dJDKNadBpjefTeOpL7Jq0sU hLnzYpj6MkeIUvLlzsAR9PAA75XqsccnOt5Wb44pkE1iqEyfYLJT7jvppOb0ArghCB3U aiiSZEELjay6jLHL3mD8WZJ+DeJ9kVoBdCzXJAJemKWaykjXM3T+6gNyZ4vQ7eIbTDsU Sd4LMtYWOt+LJEqXarqBcbVqn+H4L7PALmdqkkXdPbMC2NyrSHYlmYwwX0FoD6I8p81c 3blQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=D7uupKi2lTHg1nTREBYfC4U7HbsUj926sgl3xgaqTd0=; b=Z/ayUguHDbfm8n3WQuLImH2uFxf5GburTC7IEyzsKXPgocNsvSznCrgs05gP3Yta1Z 1a5p8nlFzl8DEI7kMT7yX1+f1+pyCrhtRUId4GAVzqJsRUL4Iy44KJXhcZ8thfD9uxXt bKp8G6bSqsPNmD7AgbL7eNHshUygksaKs6kxmoQ/FRQDfWG7hmhGj4wj0cHg3IdkW94i XunxaqfAgb+qxqTjTg0zSeeGHXSfN0WaYn/0Ixf/sgiSQ6OR2V1m2APyZPFthkV4JYB+ gvvpol74yrBRNbJwvd/tk39MoGd3y6aJFaY41AhCi7ZDMkIwrIHoSAd6bqZdu2Ccz+JN kBKA== X-Gm-Message-State: AOAM531JhHgqEkxk5Ez+q+dIJB6eXoEtG2p+ugqOVu9NZlJS7tvnO27E w3h9XFr+4x6MxDJ6wgqBb3y+5XPtKQ40/rV5 X-Google-Smtp-Source: ABdhPJykC0JY5d7rIaOq+MAqm+QaT5pR/4R471Z55M1imOLkxialCK8BI686kFFIPWNpqaYfjLcRPQ== X-Received: by 2002:a1c:4c14:: with SMTP id z20mr30684129wmf.149.1607991845077; Mon, 14 Dec 2020 16:24:05 -0800 (PST) Received: from localhost.localdomain ([85.255.232.163]) by smtp.gmail.com with ESMTPSA id b19sm5362012wmj.37.2020.12.14.16.24.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Dec 2020 16:24:04 -0800 (PST) From: Pavel Begunkov To: linux-block@vger.kernel.org Cc: Jens Axboe , Christoph Hellwig , Matthew Wilcox , Ming Lei , Johannes Weiner , Alexander Viro , "Darrick J . Wong" , "Martin K . Petersen" , Jonathan Corbet , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, target-devel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-doc@vger.kernel.org Subject: [PATCH v1 2/6] iov_iter: optimise bvec iov_iter_advance() Date: Tue, 15 Dec 2020 00:20:21 +0000 Message-Id: <5c9c22dbeecad883ca29b31896c262a8d2a77132.1607976425.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: target-devel@vger.kernel.org iov_iter_advance() is heavily used, but implemented through generic iteration. As bvecs have a specifically crafted advance() function, i.e. bvec_iter_advance(), which is faster and slimmer, use it instead. Signed-off-by: Pavel Begunkov Reviewed-by: Christoph Hellwig --- lib/iov_iter.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 1635111c5bd2..5b186dc2c9ea 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1067,6 +1067,21 @@ static void pipe_advance(struct iov_iter *i, size_t size) pipe_truncate(i); } +static void iov_iter_bvec_advance(struct iov_iter *i, size_t size) +{ + struct bvec_iter bi; + + bi.bi_size = i->count; + bi.bi_bvec_done = i->iov_offset; + bi.bi_idx = 0; + bvec_iter_advance(i->bvec, &bi, size); + + i->bvec += bi.bi_idx; + i->nr_segs -= bi.bi_idx; + i->count = bi.bi_size; + i->iov_offset = bi.bi_bvec_done; +} + void iov_iter_advance(struct iov_iter *i, size_t size) { if (unlikely(iov_iter_is_pipe(i))) { @@ -1077,6 +1092,10 @@ void iov_iter_advance(struct iov_iter *i, size_t size) i->count -= size; return; } + if (iov_iter_is_bvec(i)) { + iov_iter_bvec_advance(i, size); + return; + } iterate_and_advance(i, size, v, 0, 0, 0) } EXPORT_SYMBOL(iov_iter_advance);