From patchwork Wed Jul 28 08:16:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 12405193 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=-16.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 76A1DC4338F for ; Wed, 28 Jul 2021 08:17:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5D94460F41 for ; Wed, 28 Jul 2021 08:17:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235274AbhG1IRe (ORCPT ); Wed, 28 Jul 2021 04:17:34 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:52373 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235198AbhG1IRd (ORCPT ); Wed, 28 Jul 2021 04:17:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1627460251; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=tiKN7ZMX6RFq85lNKK9U+YCGtNyqxmDw2V9siNIiayo=; b=KNK0cCBd6g7rFg9uhg8DmqC64U1/CrjfIL9iMi7cU6JhKjH9mBXVc8jpEmloBVJJserAWv Ws0cU7iNHq0wD5y6qKgjbRapwUzCWEQ1pl8JU2WpHZBuqxBKSWOomB3F0sQ/2HU5vxZWIn eA8NRFZnh8Bx0PmEDt3u4uCbQFHehSQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-45-oh3VfoJ0PNSfH9RozqK2ng-1; Wed, 28 Jul 2021 04:17:30 -0400 X-MC-Unique: oh3VfoJ0PNSfH9RozqK2ng-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D946E39381; Wed, 28 Jul 2021 08:17:28 +0000 (UTC) Received: from localhost (ovpn-13-99.pek2.redhat.com [10.72.13.99]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4C53D19C79; Wed, 28 Jul 2021 08:17:20 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Christoph Hellwig , Dan Schatzberg , Ming Lei Subject: [PATCH V2 6/7] loop: use xarray to store workers Date: Wed, 28 Jul 2021 16:16:37 +0800 Message-Id: <20210728081638.1500953-7-ming.lei@redhat.com> In-Reply-To: <20210728081638.1500953-1-ming.lei@redhat.com> References: <20210728081638.1500953-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org css->id is unique in io controller wide, so replace rbtree with xarray for querying/storing 'blkcg_css' by using css->id as key, then code is simplified a lot. Acked-by: Dan Schatzberg Signed-off-by: Ming Lei --- drivers/block/loop.c | 36 ++++++++++++++---------------------- drivers/block/loop.h | 3 ++- 2 files changed, 16 insertions(+), 23 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 74682c0f3f86..9b22e5469ed3 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -918,7 +918,6 @@ static void loop_config_discard(struct loop_device *lo) } struct loop_worker { - struct rb_node rb_node; struct work_struct work; struct list_head cmd_list; struct list_head idle_list; @@ -966,35 +965,23 @@ static struct cgroup_subsys_state *loop_rq_get_memcg_css( static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd) { - struct rb_node **node = &(lo->worker_tree.rb_node), *parent = NULL; - struct loop_worker *cur_worker, *worker = NULL; + struct loop_worker *worker = NULL; struct work_struct *work; struct list_head *cmd_list; struct cgroup_subsys_state *blkcg_css = loop_rq_blkcg_css(cmd); + gfp_t gfp = GFP_NOWAIT | __GFP_NOWARN; spin_lock(&lo->lo_work_lock); if (queue_on_root_worker(blkcg_css)) goto queue_work; - node = &lo->worker_tree.rb_node; - - while (*node) { - parent = *node; - cur_worker = container_of(*node, struct loop_worker, rb_node); - if (cur_worker->blkcg_css == blkcg_css) { - worker = cur_worker; - break; - } else if ((long)cur_worker->blkcg_css < (long)blkcg_css) { - node = &(*node)->rb_left; - } else { - node = &(*node)->rb_right; - } - } + /* css->id is unique in each cgroup subsystem */ + worker = xa_load(&lo->workers, blkcg_css->id); if (worker) goto queue_work; - worker = kzalloc(sizeof(struct loop_worker), GFP_NOWAIT | __GFP_NOWARN); + worker = kzalloc(sizeof(*worker), gfp); /* * In the event we cannot allocate a worker, just queue on the * rootcg worker and issue the I/O as the rootcg @@ -1008,8 +995,12 @@ static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd) INIT_LIST_HEAD(&worker->cmd_list); INIT_LIST_HEAD(&worker->idle_list); worker->lo = lo; - rb_link_node(&worker->rb_node, parent, node); - rb_insert_color(&worker->rb_node, &lo->worker_tree); + + if (xa_err(xa_store(&lo->workers, blkcg_css->id, worker, gfp))) { + kfree(worker); + worker = NULL; + } + queue_work: if (worker) { /* @@ -1165,7 +1156,7 @@ static void __loop_free_idle_workers(struct loop_device *lo, bool force) LOOP_IDLE_WORKER_TIMEOUT)) break; list_del(&worker->idle_list); - rb_erase(&worker->rb_node, &lo->worker_tree); + xa_erase(&lo->workers, worker->blkcg_css->id); css_put(worker->blkcg_css); kfree(worker); } @@ -1260,7 +1251,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode, INIT_WORK(&lo->rootcg_work, loop_rootcg_workfn); INIT_LIST_HEAD(&lo->rootcg_cmd_list); INIT_LIST_HEAD(&lo->idle_worker_list); - lo->worker_tree = RB_ROOT; + xa_init(&lo->workers); INIT_DELAYED_WORK(&lo->idle_work, loop_free_idle_workers); lo->use_dio = lo->lo_flags & LO_FLAGS_DIRECT_IO; lo->lo_device = bdev; @@ -1352,6 +1343,7 @@ static int __loop_clr_fd(struct loop_device *lo, bool release) destroy_workqueue(lo->workqueue); __loop_free_idle_workers(lo, true); cancel_delayed_work_sync(&lo->idle_work); + xa_destroy(&lo->workers); spin_lock_irq(&lo->lo_lock); lo->lo_backing_file = NULL; diff --git a/drivers/block/loop.h b/drivers/block/loop.h index 9df889af1bcf..cab34da1e1bb 100644 --- a/drivers/block/loop.h +++ b/drivers/block/loop.h @@ -14,6 +14,7 @@ #include #include #include +#include #include /* Possible states of device */ @@ -59,7 +60,7 @@ struct loop_device { struct work_struct rootcg_work; struct list_head rootcg_cmd_list; struct list_head idle_worker_list; - struct rb_root worker_tree; + struct xarray workers; struct delayed_work idle_work; bool use_dio; bool sysfs_inited;