From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751818AbbGKSBI (ORCPT ); Sat, 11 Jul 2015 14:01:08 -0400 Received: from mail-yk0-f176.google.com ([209.85.160.176]:34043 "EHLO mail-yk0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751678AbbGKSBB (ORCPT ); Sat, 11 Jul 2015 14:01:01 -0400 From: Tejun Heo To: axboe@kernel.dk Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, vgoyal@redhat.com, avanzini.arianna@gmail.com, Tejun Heo Subject: [PATCH 03/11] blkcg: remove unnecessary blkcg_root handling from css_alloc/free paths Date: Sat, 11 Jul 2015 14:00:46 -0400 Message-Id: <1436637654-28110-4-git-send-email-tj@kernel.org> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1436637654-28110-1-git-send-email-tj@kernel.org> References: <1436637654-28110-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org blkcg_css_alloc() bypasses policy data allocation and blkcg_css_free() bypasses policy data and blkcg freeing for blkcg_root. There's no reason to to treat policy data any differently for blkcg_root. If the root css gets allocated after policies are registered, policy registration path will add policy data; otherwise, the alloc path will. The free path isn't never invoked for root csses. This patch removes the unnecessary special handling of blkcg_root from css_alloc/free paths. Signed-off-by: Tejun Heo Cc: Vivek Goyal --- block/blk-cgroup.c | 25 ++++++++++--------------- 1 file changed, 10 insertions(+), 15 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 64cc48f..2a493ce 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -819,18 +819,15 @@ static void blkcg_css_offline(struct cgroup_subsys_state *css) static void blkcg_css_free(struct cgroup_subsys_state *css) { struct blkcg *blkcg = css_to_blkcg(css); + int i; mutex_lock(&blkcg_pol_mutex); list_del(&blkcg->all_blkcgs_node); mutex_unlock(&blkcg_pol_mutex); - if (blkcg != &blkcg_root) { - int i; - - for (i = 0; i < BLKCG_MAX_POLS; i++) - kfree(blkcg->pd[i]); - kfree(blkcg); - } + for (i = 0; i < BLKCG_MAX_POLS; i++) + kfree(blkcg->pd[i]); + kfree(blkcg); } static struct cgroup_subsys_state * @@ -844,13 +841,12 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css) if (!parent_css) { blkcg = &blkcg_root; - goto done; - } - - blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL); - if (!blkcg) { - ret = ERR_PTR(-ENOMEM); - goto free_blkcg; + } else { + blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL); + if (!blkcg) { + ret = ERR_PTR(-ENOMEM); + goto free_blkcg; + } } for (i = 0; i < BLKCG_MAX_POLS ; i++) { @@ -877,7 +873,6 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css) pol->cpd_init_fn(blkcg); } -done: spin_lock_init(&blkcg->lock); INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_NOWAIT); INIT_HLIST_HEAD(&blkcg->blkg_list); -- 2.4.3