From patchwork Tue Dec 15 00:20:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 11973437 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,URIBL_BLOCKED,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 4F746C2BB9A for ; Tue, 15 Dec 2020 00:28:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 06CED22258 for ; Tue, 15 Dec 2020 00:28:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728578AbgLOAZQ (ORCPT ); Mon, 14 Dec 2020 19:25:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53502 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728437AbgLOAZI (ORCPT ); Mon, 14 Dec 2020 19:25:08 -0500 Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B6BFC0617B0; Mon, 14 Dec 2020 16:24:09 -0800 (PST) Received: by mail-wr1-x443.google.com with SMTP id r7so18152809wrc.5; Mon, 14 Dec 2020 16:24:09 -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=KwoEZ6JyxQmbBCmxLJQ+KWQFWoJwlaOL+90wK7NFOco=; b=CCqnIhGkYp5ddpdcS1UPTb39Ra4D+5WscVMtb6oidexSCYeRHWEJdco70zMnNXbweP Pn9+E/zWBZSVxQulIBksAPt2eJsrV+hcX5QXQ5e/rNpsVTCUypnB4O6PqOB1cPyrdig5 Z2W2sZoDSXpf3t6IsKdOTrqvZNe7gphiU7OKr3DzkP3ai/bVVx+ROIKjzGv/MjUZreFw UJYaTjClZtkxL3Qk4unb4sOP/qIqrNNTCyOMK+oyZy/vMPEVYMwnvSidQGP0uwVdVXKT RUMiYdgenV+xw4kpOcRJAQoq5G7ku8XOkHkg7hXSJdQunmwauFc9IIpAaXUTAN1K0Asq asiA== 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=KwoEZ6JyxQmbBCmxLJQ+KWQFWoJwlaOL+90wK7NFOco=; b=C8fnFApzFssakdswfeTqlZYEDLAwW0mE3Cf7u83WCfUK6eyspdxWPpSaTNRo3UoGkX FeX1xUJSCQpDmh8LpaS1FU4VQ59cwXfamSZy1KiXVoOBeJJyVHwfaiT1qIeUC0PjVxxl QzpMzww5uSYPblj9pMsZJKTWsfk0uGE/yyqrnsgVt4tm3+ldHH7zV+1VCpNSJT2GiTTI Io937H2qY53E8qXBKNQ3GjG/alxwtF5gsMok9xxeZLQo5sFWMeR+v85jKfHfs+GNJlaw kDOGaKMTT2deo9XTDFk4MRfypSPovgPm4WYyilNdAr5nwpNeNm0HusbVLMNt9vj1zxor hu0w== X-Gm-Message-State: AOAM531GiGUTbCY6fXyoB7aV6Gz1gY5LCKVEp+5A45yMbeS7EsVlWLl0 3aRIoihqCycesAxeOgqY/C+JyHDYx+fXZGcR X-Google-Smtp-Source: ABdhPJy2l/O+oho3Jx+i8vPBRwZoxDCJHPX4ZJfTmMVoBuUmrUSRDXK9gRQP/XvrS0UN33z/eOUSAg== X-Received: by 2002:a5d:6708:: with SMTP id o8mr190459wru.64.1607991847796; Mon, 14 Dec 2020 16:24:07 -0800 (PST) Received: from localhost.localdomain ([85.255.232.163]) by smtp.gmail.com with ESMTPSA id b19sm5362012wmj.37.2020.12.14.16.24.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Dec 2020 16:24:07 -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 4/6] block/psi: remove PSI annotations from direct IO Date: Tue, 15 Dec 2020 00:20:23 +0000 Message-Id: <1d3cf86668e44b3a3d35b5dbe759a086a157e434.1607976425.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: linux-block@vger.kernel.org As reported, we must not do pressure stall information accounting for direct IO, because otherwise it tells that it's thrashing a page when actually doing IO on hot data. Apparently, bio_iov_iter_get_pages() is used only by paths doing direct IO, so just make it avoid setting BIO_WORKINGSET, it also saves us CPU cycles on doing that. For fs/direct-io.c just clear the flag before submit_bio(), it's not of much concern performance-wise. Reported-by: Christoph Hellwig Suggested-by: Christoph Hellwig Suggested-by: Johannes Weiner Signed-off-by: Pavel Begunkov --- block/bio.c | 25 ++++++++++++++++--------- fs/direct-io.c | 2 ++ 2 files changed, 18 insertions(+), 9 deletions(-) diff --git a/block/bio.c b/block/bio.c index 4a8f77bb3956..3192358c411f 100644 --- a/block/bio.c +++ b/block/bio.c @@ -963,18 +963,22 @@ EXPORT_SYMBOL_GPL(bio_release_pages); static int __bio_iov_bvec_add_pages(struct bio *bio, struct iov_iter *iter) { const struct bio_vec *bv = iter->bvec; - unsigned int len; - size_t size; + struct page *page = bv->bv_page; + bool same_page = false; + unsigned int off, len; if (WARN_ON_ONCE(iter->iov_offset > bv->bv_len)) return -EINVAL; len = min_t(size_t, bv->bv_len - iter->iov_offset, iter->count); - size = bio_add_page(bio, bv->bv_page, len, - bv->bv_offset + iter->iov_offset); - if (unlikely(size != len)) - return -EINVAL; - iov_iter_advance(iter, size); + off = bv->bv_offset + iter->iov_offset; + + if (!__bio_try_merge_page(bio, page, len, off, &same_page)) { + if (bio_full(bio, len)) + return -EINVAL; + bio_add_page_noaccount(bio, page, len, off); + } + iov_iter_advance(iter, len); return 0; } @@ -1023,8 +1027,8 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) put_page(page); } else { if (WARN_ON_ONCE(bio_full(bio, len))) - return -EINVAL; - __bio_add_page(bio, page, len, offset); + return -EINVAL; + bio_add_page_noaccount(bio, page, len, offset); } offset = 0; } @@ -1099,6 +1103,9 @@ static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter) * fit into the bio, or are requested in @iter, whatever is smaller. If * MM encounters an error pinning the requested pages, it stops. Error * is returned only if 0 pages could be pinned. + * + * It also doesn't set BIO_WORKINGSET, so is intended for direct IO. If used + * otherwise the caller is responsible to do that to keep PSI happy. */ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) { diff --git a/fs/direct-io.c b/fs/direct-io.c index d53fa92a1ab6..914a7f600ecd 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -426,6 +426,8 @@ static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio) unsigned long flags; bio->bi_private = dio; + /* PSI is only for paging IO */ + bio_clear_flag(bio, BIO_WORKINGSET); spin_lock_irqsave(&dio->bio_lock, flags); dio->refcount++;