From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fengguang Wu Subject: Re: [Lsf] [RFC] writeback and cgroup Date: Mon, 16 Apr 2012 21:07:07 +0800 Message-ID: <20120416130707.GA10532@localhost> References: <20120403183655.GA23106@dhcp-172-17-108-109.mtv.corp.google.com> <20120404145134.GC12676@redhat.com> <20120407080027.GA2584@quack.suse.cz> <20120410180653.GJ21801@redhat.com> <20120410210505.GE4936@quack.suse.cz> <20120410212041.GP21801@redhat.com> <20120410222425.GF4936@quack.suse.cz> <20120411154005.GD16692@redhat.com> <1334406314.2528.90.camel@twins> <20120416125432.GB12776@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Peter Zijlstra , ctalbott@google.com, rni@google.com, andrea@betterlinux.com, containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, lsf@lists.linux-foundation.org, linux-mm@kvack.org, jmoyer@redhat.com, lizefan@huawei.com, linux-fsdevel@vger.kernel.org, cgroups@vger.kernel.org To: Vivek Goyal Return-path: Content-Disposition: inline In-Reply-To: <20120416125432.GB12776@redhat.com> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org On Mon, Apr 16, 2012 at 08:54:32AM -0400, Vivek Goyal wrote: > On Sat, Apr 14, 2012 at 02:25:14PM +0200, Peter Zijlstra wrote: > > On Wed, 2012-04-11 at 11:40 -0400, Vivek Goyal wrote: > > > > > > Ok, that's good to know. How would we configure this special bdi? I am > > > assuming there is no backing device visible in /sys/block//queue/? > > > Same is true for network file systems. > > > > root@twins:/usr/src/linux-2.6# awk '/nfs/ {print $3}' /proc/self/mountinfo | while read bdi ; do ls -la /sys/class/bdi/${bdi}/ ; done > > ls: cannot access /sys/class/bdi/0:20/: No such file or directory > > total 0 > > drwxr-xr-x 3 root root 0 2012-03-27 23:18 . > > drwxr-xr-x 35 root root 0 2012-03-27 23:02 .. > > -rw-r--r-- 1 root root 4096 2012-04-14 14:22 max_ratio > > -rw-r--r-- 1 root root 4096 2012-04-14 14:22 min_ratio > > drwxr-xr-x 2 root root 0 2012-04-14 14:22 power > > -rw-r--r-- 1 root root 4096 2012-04-14 14:22 read_ahead_kb > > lrwxrwxrwx 1 root root 0 2012-03-27 23:18 subsystem -> ../../../../class/bdi > > -rw-r--r-- 1 root root 4096 2012-03-27 23:18 uevent > > Ok, got it. So /proc/self/mountinfo has the information about st_dev and > one can use that to reach to associated bdi. Thanks Peter. Vivek, I noticed these lines in cfq code sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); Why not use bdi->dev->devt? The problem is that dev_name() will return "btrfs-X" for btrfs rather than "major:minor". Thanks, Fengguang -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org