From patchwork Wed Nov 20 21:51:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dennis Zhou X-Patchwork-Id: 11254879 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 457CA14E5 for ; Wed, 20 Nov 2019 21:51:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D5C820708 for ; Wed, 20 Nov 2019 21:51:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574286706; bh=ZIryzWWm3A0ZGINOIzfl1rloF65HluyrDOOMcCuLO5g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:In-Reply-To: References:List-ID:From; b=Gs60cFmZ73kErZj5e0pDsteiEsQ69axFsmnPcvGJ30KBMV1PWPKfc4QawCaPI8uwp RclFW3s+Z1rogKyZwo1SlaKUYR5k6HEarPJL4k1Tm6SMiUIvUJ7cXMVkKhD/sXia0t L7MJuTj63U/9eeFBxwdQT0fSxT3jgpcY8uQ6PaqY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726948AbfKTVvp (ORCPT ); Wed, 20 Nov 2019 16:51:45 -0500 Received: from mail-qk1-f194.google.com ([209.85.222.194]:44197 "EHLO mail-qk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726937AbfKTVvo (ORCPT ); Wed, 20 Nov 2019 16:51:44 -0500 Received: by mail-qk1-f194.google.com with SMTP id m16so1221202qki.11 for ; Wed, 20 Nov 2019 13:51:43 -0800 (PST) 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:in-reply-to:references; bh=aIsZrPjDR5Q3Wx2yMUYueo89CedV8IzCUczQTS+axds=; b=hqlHPuOGK2sWM+PXmmY8jhOOlpvPtkTPbPkrGicTGld1X7DayezE60PC6/Rgu8Dpg+ VZHWXZebrpGUtRxhXys10av46YFHwpx7ctZEvYmllSdZUTWE8xoBC6dSyfwL1xBnXTXx 4QkbbzFZ8T76n9kZYo3JMbhPCa7BL9TT/QS4Ph/Lec+B66O/AaLR//jUoI9Th3IYVZSH hlub/YFuodtKFavHEdhdKpvziFvikWRh1oX08hZ4HyWGsuIhfZ+GGO82sivrrECu5eIz h9IHjRHNAUxaLzuutm/5CLhMvHbxgX2KNuhDKrFdFXqtui/nim/KbJwHd/fx0V97XsNY NhBQ== X-Gm-Message-State: APjAAAWePfRyXlf61kJXLcSw4wjh6hI3gxw35cUmCkGpNT4SFTvkQkWf n1+KAU5WSUZFlzSHOypzw4Q= X-Google-Smtp-Source: APXvYqwhGEH/CaHDtTXLLG8Iih7bQD0z3J3KKvX/lfxJbrLt4S2qaCTVAntoOfjg4UNwBSsL0BFYrg== X-Received: by 2002:a37:9e8a:: with SMTP id h132mr4486116qke.58.1574286702810; Wed, 20 Nov 2019 13:51:42 -0800 (PST) Received: from dennisz-mbp.thefacebook.com ([163.114.130.128]) by smtp.gmail.com with ESMTPSA id t16sm303820qkm.73.2019.11.20.13.51.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 20 Nov 2019 13:51:42 -0800 (PST) From: Dennis Zhou To: David Sterba , Chris Mason , Josef Bacik , Omar Sandoval Cc: kernel-team@fb.com, linux-btrfs@vger.kernel.org, Dennis Zhou Subject: [PATCH 13/22] btrfs: calculate discard delay based on number of extents Date: Wed, 20 Nov 2019 16:51:12 -0500 Message-Id: <12edbf9dd781b8db87febb6263409ea77d38696f.1574282259.git.dennis@kernel.org> X-Mailer: git-send-email 2.13.5 In-Reply-To: References: In-Reply-To: References: Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Use the number of discardable extents to help guide our discard delay interval. This value is reevaluated every transaction commit. Signed-off-by: Dennis Zhou Reviewed-by: Josef Bacik --- fs/btrfs/ctree.h | 2 ++ fs/btrfs/discard.c | 53 ++++++++++++++++++++++++++++++++++++++---- fs/btrfs/discard.h | 1 + fs/btrfs/extent-tree.c | 4 +++- fs/btrfs/sysfs.c | 31 ++++++++++++++++++++++++ 5 files changed, 86 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 5b13bda52ab7..78b970cfd108 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -469,6 +469,8 @@ struct btrfs_discard_ctl { struct list_head discard_list[BTRFS_NR_DISCARD_LISTS]; atomic_t discardable_extents; atomic64_t discardable_bytes; + u32 delay; + u32 iops_limit; }; /* delayed seq elem */ diff --git a/fs/btrfs/discard.c b/fs/btrfs/discard.c index 074341c8242a..f40bff5621d9 100644 --- a/fs/btrfs/discard.c +++ b/fs/btrfs/discard.c @@ -14,6 +14,11 @@ /* This is an initial delay to give some chance for lba reuse. */ #define BTRFS_DISCARD_DELAY (120ULL * NSEC_PER_SEC) +/* Target completion latency of discarding all discardable extents. */ +#define BTRFS_DISCARD_TARGET_MSEC (6 * 60 * 60ULL * MSEC_PER_SEC) +#define BTRFS_DISCARD_MAX_DELAY (10000UL) +#define BTRFS_DISCARD_MAX_IOPS (10UL) + static struct list_head *btrfs_get_discard_list( struct btrfs_discard_ctl *discard_ctl, struct btrfs_block_group *block_group) @@ -231,11 +236,18 @@ void btrfs_discard_schedule_work(struct btrfs_discard_ctl *discard_ctl, block_group = find_next_block_group(discard_ctl, now); if (block_group) { - u64 delay = 0; + u32 delay = discard_ctl->delay; + + /* + * This timeout is to hopefully prevent immediate discarding + * in a recently allocated block group. + */ + if (now < block_group->discard_eligible_time) { + u64 bg_timeout = (block_group->discard_eligible_time - + now); - if (now < block_group->discard_eligible_time) - delay = nsecs_to_jiffies( - block_group->discard_eligible_time - now); + delay = max_t(u64, delay, nsecs_to_jiffies(bg_timeout)); + } mod_delayed_work(discard_ctl->discard_workers, &discard_ctl->work, @@ -341,6 +353,37 @@ bool btrfs_run_discard_work(struct btrfs_discard_ctl *discard_ctl) test_bit(BTRFS_FS_DISCARD_RUNNING, &fs_info->flags)); } +/** + * btrfs_discard_calc_delay - recalculate the base delay + * @discard_ctl: discard control + * + * Recalculate the base delay which is based off the total number of + * discardable_extents. Clamp this with the iops_limit and + * BTRFS_DISCARD_MAX_DELAY. + */ +void btrfs_discard_calc_delay(struct btrfs_discard_ctl *discard_ctl) +{ + s32 discardable_extents = + atomic_read(&discard_ctl->discardable_extents); + s32 iops_limit; + unsigned long delay; + + if (!discardable_extents) + return; + + spin_lock(&discard_ctl->lock); + + iops_limit = READ_ONCE(discard_ctl->iops_limit); + if (iops_limit) + iops_limit = MSEC_PER_SEC / iops_limit; + + delay = BTRFS_DISCARD_TARGET_MSEC / discardable_extents; + delay = clamp_t(s32, delay, iops_limit, BTRFS_DISCARD_MAX_DELAY); + discard_ctl->delay = msecs_to_jiffies(delay); + + spin_unlock(&discard_ctl->lock); +} + /** * btrfs_discard_update_discardable - propagate discard counters * @block_group: block_group of interest @@ -470,6 +513,8 @@ void btrfs_discard_init(struct btrfs_fs_info *fs_info) atomic_set(&discard_ctl->discardable_extents, 0); atomic64_set(&discard_ctl->discardable_bytes, 0); + discard_ctl->delay = BTRFS_DISCARD_MAX_DELAY; + discard_ctl->iops_limit = BTRFS_DISCARD_MAX_IOPS; } void btrfs_discard_cleanup(struct btrfs_fs_info *fs_info) diff --git a/fs/btrfs/discard.h b/fs/btrfs/discard.h index 75f00a84d540..88f1363aa4e4 100644 --- a/fs/btrfs/discard.h +++ b/fs/btrfs/discard.h @@ -23,6 +23,7 @@ void btrfs_discard_schedule_work(struct btrfs_discard_ctl *discard_ctl, bool btrfs_run_discard_work(struct btrfs_discard_ctl *discard_ctl); /* Update operations. */ +void btrfs_discard_calc_delay(struct btrfs_discard_ctl *discard_ctl); void btrfs_discard_update_discardable(struct btrfs_block_group *block_group, struct btrfs_free_space_ctl *ctl); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 40e965b06f8f..2d821c6c7698 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2941,8 +2941,10 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans) cond_resched(); } - if (btrfs_test_opt(fs_info, DISCARD_ASYNC)) + if (btrfs_test_opt(fs_info, DISCARD_ASYNC)) { + btrfs_discard_calc_delay(&fs_info->discard_ctl); btrfs_discard_schedule_work(&fs_info->discard_ctl, true); + } /* * Transaction is finished. We don't need the lock anymore. We diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 07098f6d62bd..043430ae3818 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -344,6 +344,36 @@ static const struct attribute_group btrfs_static_feature_attr_group = { */ #define discard_to_fs_info(_kobj) to_fs_info((_kobj)->parent->parent) +static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj, + struct kobj_attribute *a, + char *buf) +{ + struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj); + + return snprintf(buf, PAGE_SIZE, "%u\n", + READ_ONCE(fs_info->discard_ctl.iops_limit)); +} + +static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj, + struct kobj_attribute *a, + const char *buf, size_t len) +{ + struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj); + struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl; + u32 iops_limit; + int ret; + + ret = kstrtou32(buf, 10, &iops_limit); + if (ret) + return -EINVAL; + + WRITE_ONCE(discard_ctl->iops_limit, iops_limit); + + return len; +} +BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show, + btrfs_discard_iops_limit_store); + static ssize_t btrfs_discardable_extents_show(struct kobject *kobj, struct kobj_attribute *a, char *buf) @@ -367,6 +397,7 @@ static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj, BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show); static const struct attribute *discard_debug_attrs[] = { + BTRFS_ATTR_PTR(discard, iops_limit), BTRFS_ATTR_PTR(discard, discardable_extents), BTRFS_ATTR_PTR(discard, discardable_bytes), NULL,