From patchwork Wed Apr 25 00:20:17 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Timofey Titovets X-Patchwork-Id: 10361315 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 37CFD601BE for ; Wed, 25 Apr 2018 00:25:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2B2EE28E3C for ; Wed, 25 Apr 2018 00:25:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1F63128E7D; Wed, 25 Apr 2018 00:25:50 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.3 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_WEB,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8B04028E3C for ; Wed, 25 Apr 2018 00:25:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751247AbeDYAYq (ORCPT ); Tue, 24 Apr 2018 20:24:46 -0400 Received: from mail-lf0-f68.google.com ([209.85.215.68]:44095 "EHLO mail-lf0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750929AbeDYAYp (ORCPT ); Tue, 24 Apr 2018 20:24:45 -0400 Received: by mail-lf0-f68.google.com with SMTP id g203-v6so22888178lfg.11 for ; Tue, 24 Apr 2018 17:24:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=dga82sY4iRsPf/d0lb7TRizHfsCldT+IhoDWkWaMhQc=; b=ToXimN08m/+E19+cOrvL8f7LPE6bwCaz/wHh8+r/4eqfXSwQUJBJGrp8b3TBSlN+zH Dh8d/Luh55GUq7sZq3ylLfBReUVCkSzcQG/gAqa4FIFU56yTg/+sCe+7DB1AmpO8q10n bUl7lYm2tYg88HSQ0tf2ajY6BbFtF+QamR26/CyBac/15m6BORYfrMdYrYixF30W871R dYEDaotjYj52OaaoOC+Ufco8sEDsJb7g2spUy0avA5VIO+zZPwnZvtMumx9C8EWOOP6t IvNjYhMTSmPNX7NyniKWtKqsU1l55vq9d+mPbS8GJkd7dJXvxzcoXbGKjLTgGs3P/x8a B6gw== 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:mime-version :content-transfer-encoding; bh=dga82sY4iRsPf/d0lb7TRizHfsCldT+IhoDWkWaMhQc=; b=VUGkhQLXGUiV3y/IYfsSHGXBpxTfWwQ8GOu+jAUq10aP0+Nd0idD4fnou/oryXgqIG DNw2Oz6/t1w3l8sqWGWhJ4WdfjWJt2noXGKFm4yJpFb+Zj6ALeKM72JwHCBb5aYDF28W Xgz5lgTjKEzw78kWfLkotFoubYf7wxQV4B6DH0r26lPIAeVcuRz+vOtLqLvmJ6K7t6ev JPR88XbXcxxfsPpsrf/GHc5rb4uLpZN9PSQckdhLuJIWRje4X9z8+RgKKuiB+xKZEGQ1 w3Pe6r4aCZLnKVvuJ0XSUpGJGp0tgpvOSa+y84Sjq1UZl37oSzWn0U66Y+9R9zX2YFy9 N7UQ== X-Gm-Message-State: ALQs6tB+fVz8+zWJP/+yJP0osPiaJJji3tHKRML2ljQblmaEfwH0SFZU HuDGm0gVvaWpU5BmpwqsiGR0FQ== X-Google-Smtp-Source: AB8JxZqt3QXfgOb0mTCsz87HNqIxfOYtn/GOScX7DO9Zeex+H60/skl9hO3tBP2uYUOmmBLi4pqdRA== X-Received: by 2002:a19:1567:: with SMTP id l100-v6mr13365001lfi.114.1524615883080; Tue, 24 Apr 2018 17:24:43 -0700 (PDT) Received: from localhost.localdomain ([178.121.235.109]) by smtp.gmail.com with ESMTPSA id 65sm1874802lje.6.2018.04.24.17.24.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 24 Apr 2018 17:24:42 -0700 (PDT) From: Timofey Titovets To: linux-btrfs@vger.kernel.org Cc: Timofey Titovets Subject: [PATCH V4] Btrfs: enchanse raid1/10 balance heuristic Date: Wed, 25 Apr 2018 03:20:17 +0300 Message-Id: <20180425002017.25523-1-nefelim4ag@gmail.com> X-Mailer: git-send-email 2.17.0 MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently btrfs raid1/10 balancer bаlance requests to mirrors, based on pid % num of mirrors. Make logic understood: - if one of underline devices are non rotational - Queue leght to underline devices By default try use pid % num_mirrors guessing, but: - If one of mirrors are non rotational, repick optimal to it - If underline mirror have less queue leght then optimal, repick to that mirror For avoid round-robin request balancing, lets round down queue leght: - By 8 for rotational devs - By 2 for all non rotational devs Changes: v1 -> v2: - Use helper part_in_flight() from genhd.c to get queue lenght - Move guess code to guess_optimal() - Change balancer logic, try use pid % mirror by default Make balancing on spinning rust if one of underline devices are overloaded v2 -> v3: - Fix arg for RAID10 - use sub_stripes, instead of num_stripes v3 -> v4: - Rebased on latest misc-next Signed-off-by: Timofey Titovets --- block/genhd.c | 1 + fs/btrfs/volumes.c | 111 ++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 110 insertions(+), 2 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 9656f9e9f99e..5ea5acc88d3c 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -81,6 +81,7 @@ void part_in_flight(struct request_queue *q, struct hd_struct *part, atomic_read(&part->in_flight[1]); } } +EXPORT_SYMBOL_GPL(part_in_flight); struct hd_struct *__disk_get_part(struct gendisk *disk, int partno) { diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index c95af358b71f..fa7dd6ac087f 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include "ctree.h" #include "extent_map.h" @@ -5148,7 +5149,7 @@ int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len) /* * There could be two corrupted data stripes, we need * to loop retry in order to rebuild the correct data. - * + * * Fail a stripe at a time on every retry except the * stripe under reconstruction. */ @@ -5201,6 +5202,111 @@ int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info, u64 logical, u64 len) return ret; } +/** + * bdev_get_queue_len - return rounded down in flight queue lenght of bdev + * + * @bdev: target bdev + * @round_down: round factor big for hdd and small for ssd, like 8 and 2 + */ +static int bdev_get_queue_len(struct block_device *bdev, int round_down) +{ + int sum; + struct hd_struct *bd_part = bdev->bd_part; + struct request_queue *rq = bdev_get_queue(bdev); + uint32_t inflight[2] = {0, 0}; + + part_in_flight(rq, bd_part, inflight); + + sum = max_t(uint32_t, inflight[0], inflight[1]); + + /* + * Try prevent switch for every sneeze + * By roundup output num by some value + */ + return ALIGN_DOWN(sum, round_down); +} + +/** + * guess_optimal - return guessed optimal mirror + * + * Optimal expected to be pid % num_stripes + * + * That's generaly ok for spread load + * Add some balancer based on queue leght to device + * + * Basic ideas: + * - Sequential read generate low amount of request + * so if load of drives are equal, use pid % num_stripes balancing + * - For mixed rotate/non-rotate mirrors, pick non-rotate as optimal + * and repick if other dev have "significant" less queue lenght + * - Repick optimal if queue leght of other mirror are less + */ +static int guess_optimal(struct map_lookup *map, int num, int optimal) +{ + int i; + int round_down = 8; + int qlen[num]; + bool is_nonrot[num]; + bool all_bdev_nonrot = true; + bool all_bdev_rotate = true; + struct block_device *bdev; + + if (num == 1) + return optimal; + + /* Check accessible bdevs */ + for (i = 0; i < num; i++) { + /* Init for missing bdevs */ + is_nonrot[i] = false; + qlen[i] = INT_MAX; + bdev = map->stripes[i].dev->bdev; + if (bdev) { + qlen[i] = 0; + is_nonrot[i] = blk_queue_nonrot(bdev_get_queue(bdev)); + if (is_nonrot[i]) + all_bdev_rotate = false; + else + all_bdev_nonrot = false; + } + } + + /* + * Don't bother with computation + * if only one of two bdevs are accessible + */ + if (num == 2 && qlen[0] != qlen[1]) { + if (qlen[0] < qlen[1]) + return 0; + else + return 1; + } + + if (all_bdev_nonrot) + round_down = 2; + + for (i = 0; i < num; i++) { + if (qlen[i]) + continue; + bdev = map->stripes[i].dev->bdev; + qlen[i] = bdev_get_queue_len(bdev, round_down); + } + + /* For mixed case, pick non rotational dev as optimal */ + if (all_bdev_rotate == all_bdev_nonrot) { + for (i = 0; i < num; i++) { + if (is_nonrot[i]) + optimal = i; + } + } + + for (i = 0; i < num; i++) { + if (qlen[optimal] > qlen[i]) + optimal = i; + } + + return optimal; +} + static int find_live_mirror(struct btrfs_fs_info *fs_info, struct map_lookup *map, int first, int dev_replace_is_ongoing) @@ -5219,7 +5325,8 @@ static int find_live_mirror(struct btrfs_fs_info *fs_info, else num_stripes = map->num_stripes; - preferred_mirror = first + current->pid % num_stripes; + preferred_mirror = first + guess_optimal(map, num_stripes, + current->pid % num_stripes); if (dev_replace_is_ongoing && fs_info->dev_replace.cont_reading_from_srcdev_mode ==