From patchwork Wed Jan 25 13:34:33 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13115621 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A48134C6D for ; Wed, 25 Jan 2023 13:34:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=jVkXgiX++B6ZRBSVBAQLBWXDo+TKW/LQnC8PttvWfoI=; b=jpPymmd9O3sK/QGD+ihLjY6MQw DujfARMhHkJboFbptXRG3wcOjROYaih0gEIyYQ62LZVDUAgArAKCyD8OCwjzY6z/naqsY2qirNzk6 ilVJSvbs/au6I8kbHKpxEMoXr4kQ+PIXBx1Xx05PUmL47nkfz1F+kf+Vv2AKaDc+l3ObIsNC38cn8 JxvQTVAJfCpZs6htcmZCXlun2hpg6aZGiqB+MjWGH2YZ1xt9fR7clMZ5B8g0ihcuH/72NKZHCUQHv wY9Mvjy501914NspkIOys3opWFybPv4UVzJIlny+xpsxGrYLH50vRDjbdL9W0IIis2vQexz/hNkUn YYxaSGBA==; Received: from [2001:4bb8:19a:27af:c78f:9b0d:b95c:d248] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1pKfvS-007P3i-N5; Wed, 25 Jan 2023 13:34:55 +0000 From: Christoph Hellwig To: Jens Axboe , Minchan Kim , Sergey Senozhatsky , Dan Williams , Vishal Verma , Dave Jiang , Ira Weiny Cc: Andrew Morton , linux-block@vger.kernel.org, nvdimm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 4/7] mm: use an on-stack bio for synchronous swapin Date: Wed, 25 Jan 2023 14:34:33 +0100 Message-Id: <20230125133436.447864-5-hch@lst.de> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230125133436.447864-1-hch@lst.de> References: <20230125133436.447864-1-hch@lst.de> Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Optimize the synchronous swap in case by using an on-stack bio instead of allocating one using bio_alloc. Signed-off-by: Christoph Hellwig --- mm/page_io.c | 69 +++++++++++++++++++++++++++++----------------------- 1 file changed, 38 insertions(+), 31 deletions(-) diff --git a/mm/page_io.c b/mm/page_io.c index ce0b3638094f85..21ce4505f00607 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -52,10 +52,9 @@ static void end_swap_bio_write(struct bio *bio) bio_put(bio); } -static void end_swap_bio_read(struct bio *bio) +static void __end_swap_bio_read(struct bio *bio) { struct page *page = bio_first_page_all(bio); - struct task_struct *waiter = bio->bi_private; if (bio->bi_status) { SetPageError(page); @@ -63,18 +62,16 @@ static void end_swap_bio_read(struct bio *bio) pr_alert_ratelimited("Read-error on swap-device (%u:%u:%llu)\n", MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)), (unsigned long long)bio->bi_iter.bi_sector); - goto out; + } else { + SetPageUptodate(page); } - - SetPageUptodate(page); -out: unlock_page(page); - WRITE_ONCE(bio->bi_private, NULL); +} + +static void end_swap_bio_read(struct bio *bio) +{ + __end_swap_bio_read(bio); bio_put(bio); - if (waiter) { - blk_wake_io_task(waiter); - put_task_struct(waiter); - } } int generic_swapfile_activate(struct swap_info_struct *sis, @@ -445,10 +442,11 @@ static void swap_readpage_fs(struct page *page, *plug = sio; } -static void swap_readpage_bdev(struct page *page, bool synchronous, +static void swap_readpage_bdev_sync(struct page *page, struct swap_info_struct *sis) { - struct bio *bio; + struct bio_vec bv; + struct bio bio; if ((sis->flags & SWP_SYNCHRONOUS_IO) && !bdev_read_page(sis->bdev, swap_page_sector(page), page)) { @@ -456,30 +454,37 @@ static void swap_readpage_bdev(struct page *page, bool synchronous, return; } - bio = bio_alloc(sis->bdev, 1, REQ_OP_READ, GFP_KERNEL); - bio->bi_iter.bi_sector = swap_page_sector(page); - bio->bi_end_io = end_swap_bio_read; - bio_add_page(bio, page, thp_size(page), 0); + bio_init(&bio, sis->bdev, &bv, 1, REQ_OP_READ); + bio.bi_iter.bi_sector = swap_page_sector(page); + bio_add_page(&bio, page, thp_size(page), 0); /* * Keep this task valid during swap readpage because the oom killer may * attempt to access it in the page fault retry time check. */ - if (synchronous) { - get_task_struct(current); - bio->bi_private = current; - } + get_task_struct(current); count_vm_event(PSWPIN); - bio_get(bio); - submit_bio(bio); - while (synchronous) { - set_current_state(TASK_UNINTERRUPTIBLE); - if (!READ_ONCE(bio->bi_private)) - break; + submit_bio_wait(&bio); + __end_swap_bio_read(&bio); + put_task_struct(current); +} + +static void swap_readpage_bdev_async(struct page *page, + struct swap_info_struct *sis) +{ + struct bio *bio; - blk_io_schedule(); + if ((sis->flags & SWP_SYNCHRONOUS_IO) && + !bdev_read_page(sis->bdev, swap_page_sector(page), page)) { + count_vm_event(PSWPIN); + return; } - __set_current_state(TASK_RUNNING); - bio_put(bio); + + bio = bio_alloc(sis->bdev, 1, REQ_OP_READ, GFP_KERNEL); + bio->bi_iter.bi_sector = swap_page_sector(page); + bio->bi_end_io = end_swap_bio_read; + bio_add_page(bio, page, thp_size(page), 0); + count_vm_event(PSWPIN); + submit_bio(bio); } void swap_readpage(struct page *page, bool synchronous, struct swap_iocb **plug) @@ -509,8 +514,10 @@ void swap_readpage(struct page *page, bool synchronous, struct swap_iocb **plug) unlock_page(page); } else if (data_race(sis->flags & SWP_FS_OPS)) { swap_readpage_fs(page, plug); + } else if (synchronous) { + swap_readpage_bdev_sync(page, sis); } else { - swap_readpage_bdev(page, synchronous, sis); + swap_readpage_bdev_async(page, sis); } if (workingset) {