From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9366C63797 for ; Tue, 17 Jan 2023 08:13:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235873AbjAQINS (ORCPT ); Tue, 17 Jan 2023 03:13:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236025AbjAQINQ (ORCPT ); Tue, 17 Jan 2023 03:13:16 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B11222196A; Tue, 17 Jan 2023 00:13:15 -0800 (PST) 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=yXYe7SJq+Eosgyb2tF7aEpHVQ7rDIKeIsjwILkXlOls=; b=JiD8mlKNf/sVBHwj5TV2B9Qf5e 8hMcsZGIZmPebWBpjzIukoQnLn3oII0EkU815/NNTFix1jEGIXo1NjcGo09pHHiQQahi3Sf6VIyaK mvR/Fd345pP43Y4H9sOqoWWKb7dHdliy12mXGhXU0fEENM/3vajIAV+FGR/V6eblYZEeCAiJvjGC/ 5QcSaQXxqkIzWCNhg5vSnYT4hu+Wb6BdyDvAHBdSyuCMwWPXXvZw3f/3eReqFhC/q8ctaGYrIDcG0 ft1ezN6eqJttyu/FIHTiUESYZDhhSbqoWu0bMAiD/6tKQLBPBQH1kLEe8uVviNuJnfrRaqwfJPxl1 ZuANZXxw==; Received: from [2001:4bb8:19a:2039:eaa2:3b9e:be2e:bd2a] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1pHh5l-00DHim-FV; Tue, 17 Jan 2023 08:13:13 +0000 From: Christoph Hellwig To: Jens Axboe , Tejun Heo , Josef Bacik Cc: linux-block@vger.kernel.org, cgroups@vger.kernel.org Subject: [PATCH 05/15] blk-cgroup: store a gendisk to throttle in struct task_struct Date: Tue, 17 Jan 2023 09:12:47 +0100 Message-Id: <20230117081257.3089859-6-hch@lst.de> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230117081257.3089859-1-hch@lst.de> References: <20230117081257.3089859-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Switch from a request_queue pointer and reference to a gendisk once for the throttle information in struct task_struct. Move the check for the dead disk to the latest place now that is is unboundled from the reference grab. Signed-off-by: Christoph Hellwig --- block/blk-cgroup.c | 37 +++++++++++++++++++------------------ include/linux/sched.h | 2 +- kernel/fork.c | 2 +- mm/swapfile.c | 2 +- 4 files changed, 22 insertions(+), 21 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index f5a634ed098db0..603e911d1350db 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1334,9 +1334,9 @@ static void blkcg_bind(struct cgroup_subsys_state *root_css) static void blkcg_exit(struct task_struct *tsk) { - if (tsk->throttle_queue) - blk_put_queue(tsk->throttle_queue); - tsk->throttle_queue = NULL; + if (tsk->throttle_disk) + put_disk(tsk->throttle_disk); + tsk->throttle_disk = NULL; } struct cgroup_subsys io_cgrp_subsys = { @@ -1778,29 +1778,32 @@ static void blkcg_maybe_throttle_blkg(struct blkcg_gq *blkg, bool use_memdelay) * * This is only called if we've been marked with set_notify_resume(). Obviously * we can be set_notify_resume() for reasons other than blkcg throttling, so we - * check to see if current->throttle_queue is set and if not this doesn't do + * check to see if current->throttle_disk is set and if not this doesn't do * anything. This should only ever be called by the resume code, it's not meant * to be called by people willy-nilly as it will actually do the work to * throttle the task if it is setup for throttling. */ void blkcg_maybe_throttle_current(void) { - struct request_queue *q = current->throttle_queue; + struct gendisk *disk = current->throttle_disk; struct blkcg *blkcg; struct blkcg_gq *blkg; bool use_memdelay = current->use_memdelay; - if (!q) + if (!disk) return; - current->throttle_queue = NULL; + current->throttle_disk = NULL; current->use_memdelay = false; + if (test_bit(GD_DEAD, &disk->state)) + goto out_put_disk; + rcu_read_lock(); blkcg = css_to_blkcg(blkcg_css()); if (!blkcg) goto out; - blkg = blkg_lookup(blkcg, q); + blkg = blkg_lookup(blkcg, disk->queue); if (!blkg) goto out; if (!blkg_tryget(blkg)) @@ -1809,11 +1812,12 @@ void blkcg_maybe_throttle_current(void) blkcg_maybe_throttle_blkg(blkg, use_memdelay); blkg_put(blkg); - blk_put_queue(q); + put_disk(disk); return; out: rcu_read_unlock(); - blk_put_queue(q); +out_put_disk: + put_disk(disk); } /** @@ -1835,18 +1839,15 @@ void blkcg_maybe_throttle_current(void) */ void blkcg_schedule_throttle(struct gendisk *disk, bool use_memdelay) { - struct request_queue *q = disk->queue; - if (unlikely(current->flags & PF_KTHREAD)) return; - if (current->throttle_queue != q) { - if (!blk_get_queue(q)) - return; + if (current->throttle_disk != disk) { + get_device(disk_to_dev(disk)); - if (current->throttle_queue) - blk_put_queue(current->throttle_queue); - current->throttle_queue = q; + if (current->throttle_disk) + put_disk(current->throttle_disk); + current->throttle_disk = disk; } if (use_memdelay) diff --git a/include/linux/sched.h b/include/linux/sched.h index 853d08f7562bda..6f6ce9ca709798 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1436,7 +1436,7 @@ struct task_struct { #endif #ifdef CONFIG_BLK_CGROUP - struct request_queue *throttle_queue; + struct gendisk *throttle_disk; #endif #ifdef CONFIG_UPROBES diff --git a/kernel/fork.c b/kernel/fork.c index 9f7fe354189785..d9c97704b7c9a4 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1044,7 +1044,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) #endif #ifdef CONFIG_BLK_CGROUP - tsk->throttle_queue = NULL; + tsk->throttle_disk = NULL; tsk->use_memdelay = 0; #endif diff --git a/mm/swapfile.c b/mm/swapfile.c index 908a529bca12c9..3e0a742fb7bbff 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3642,7 +3642,7 @@ void __cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask) * We've already scheduled a throttle, avoid taking the global swap * lock. */ - if (current->throttle_queue) + if (current->throttle_disk) return; spin_lock(&swap_avail_lock); -- 2.39.0