From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f42.google.com (mail-oi0-f42.google.com [209.85.218.42]) by kanga.kvack.org (Postfix) with ESMTP id 344B26B006E for ; Wed, 25 Mar 2015 11:41:03 -0400 (EDT) Received: by oicf142 with SMTP id f142so15595620oic.3 for ; Wed, 25 Mar 2015 08:41:02 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id i79si1882869oig.54.2015.03.25.08.41.02 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 25 Mar 2015 08:41:02 -0700 (PDT) Date: Wed, 25 Mar 2015 11:40:22 -0400 From: Vivek Goyal Subject: Re: [PATCHSET 1/3 v2 block/for-4.1/core] writeback: cgroup writeback support Message-ID: <20150325154022.GC29728@redhat.com> References: <1427086499-15657-1-git-send-email-tj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1427086499-15657-1-git-send-email-tj@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: axboe@kernel.dk, linux-kernel@vger.kernel.org, jack@suse.cz, hch@infradead.org, hannes@cmpxchg.org, linux-fsdevel@vger.kernel.org, lizefan@huawei.com, cgroups@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.cz, clm@fb.com, fengguang.wu@intel.com, david@fromorbit.com, gthelen@google.com On Mon, Mar 23, 2015 at 12:54:11AM -0400, Tejun Heo wrote: > > > How to test > ----------- > > * Boot with kernel option "cgroup__DEVEL__legacy_files_on_dfl". > > * umount /sys/fs/cgroup/memory > umount /sys/fs/cgroup/blkio > mkdir /sys/fs/cgroup/unified > mount -t cgroup -o __DEVEL__sane_behavior cgroup /sys/fs/cgroup/unified > echo +blkio > /sys/fs/cgroup/unified/cgroup.subtree_control > > * Build the cgroup hierarchy (don't forget to enable blkio using > subtree_control) and put processes in cgroups and run tests on ext2 > filesystems and blkio.throttle.* knobs. > [..] > This patchset is on top of > > block/for-4.1/core bfd343aa1718 ("blk-mq: don't wait in blk_mq_queue_enter() if __GFP_WAIT isn't set") > + [1] [PATCH] writeback: fix possible underflow in write bandwidth calculation > > and available in the following git branch. > > git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git review-cgroup-writeback-20150322 > Hi Tejun, Great Work. I tried to do some basic testing and it seems to work. I used "review-cgroup-writeback-switch-20150322" branch for my testing. I have 32G of RAM on my system and I setup a write bandwidth of 1MB/s on the disk and allowed a dd to run. That dd quickly consumed 5G of page cache before it reached to a steady state. Sounds like too much of cache consumption which will be drained at a speed of 1MB/s. Not sure if this is expected or bdi back-pressure is not being applied soon enough. Thanks Vivek -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org