From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH 27/48] writeback, blkcg: propagate non-root blkcg congestion state Date: Mon, 23 Mar 2015 00:54:38 -0400 Message-ID: <1427086499-15657-28-git-send-email-tj@kernel.org> References: <1427086499-15657-1-git-send-email-tj@kernel.org> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=eZUjCGIC0NMGaZPwzrArbcgMoDGRLA3NkyicuPGgU5g=; b=ZP1wdgViJ5wjzHv9ZyVVYB0oksXX3CEQszf/vSQla8A3IsmDtOvEV7ygQNxpzcyEQx N2H1VRko6Gq06Tdh3L8ukCrcrxnNK7gbo8RJ6vbkxCZX7RDkclI3Jj/4IHFr+BbUzkn0 RRzfhNLxZR3Hg5jDykqqAA+DD4q5NwA604OjKgXz8RnnS66go4eCkEFnEJ67fUszIraC ipJCWlYRVRUesyBVegiuqmiMUit93IoGCrlNMzKEogJki1ssukvjaB7UQruraaAw1WQd OFQ5azfsswyjvESRAk1SUpgYwY+wgDObFcHyXAINGLSkLqPk4hnSIJumGS/Y8IU65tiw M4MA== In-Reply-To: <1427086499-15657-1-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, jack-AlSwsSmVLrQ@public.gmane.org, hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, mhocko-AlSwsSmVLrQ@public.gmane.org, clm-b10kYP2dOMg@public.gmane.org, fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org, gthelen-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, Tejun Heo Now that bdi layer can handle per-blkcg bdi_writeback_congested state, blk_{set|clear}_congested() can propagate non-root blkcg congestion state to them. This can be easily achieved by disabling the root_rl tests in blk_{set|clear}_congested(). Note that we still need those tests when !CONFIG_CGROUP_WRITEBACK as otherwise we'll end up flipping root blkcg wb's congestion state for events happening on other blkcgs. v2: Updated for bdi_writeback_congested. Signed-off-by: Tejun Heo Cc: Jens Axboe Cc: Jan Kara Cc: Vivek Goyal --- block/blk-core.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index cad26e3..95488fb 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -65,23 +65,26 @@ static struct workqueue_struct *kblockd_workqueue; static void blk_clear_congested(struct request_list *rl, int sync) { - if (rl != &rl->q->root_rl) - return; #ifdef CONFIG_CGROUP_WRITEBACK clear_wb_congested(rl->blkg->wb_congested, sync); #else - clear_wb_congested(rl->q->backing_dev_info.wb.congested, sync); + /* + * If !CGROUP_WRITEBACK, all blkg's map to bdi->wb and we shouldn't + * flip its congestion state for events on other blkcgs. + */ + if (rl == &rl->q->root_rl) + clear_wb_congested(rl->q->backing_dev_info.wb.congested, sync); #endif } static void blk_set_congested(struct request_list *rl, int sync) { - if (rl != &rl->q->root_rl) - return; #ifdef CONFIG_CGROUP_WRITEBACK set_wb_congested(rl->blkg->wb_congested, sync); #else - set_wb_congested(rl->q->backing_dev_info.wb.congested, sync); + /* see blk_clear_congested() */ + if (rl == &rl->q->root_rl) + set_wb_congested(rl->q->backing_dev_info.wb.congested, sync); #endif } -- 2.1.0