From: Mike Galbraith <efault@gmx.de>
To: Alexey Vlasov <renton@renton.name>
Cc: linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com
Subject: Re: Attaching a process to cgroups
Date: Wed, 25 Jul 2012 15:57:47 +0200 [thread overview]
Message-ID: <1343224667.5745.67.camel@marge.simpson.net> (raw)
In-Reply-To: <20120725133637.GA9169@beaver>
On Wed, 2012-07-25 at 17:36 +0400, Alexey Vlasov wrote:
> Hi.
>
> Now I've got almost 5k used groups and it got even worse. Now I've got
> almost 5k used groups and it got even worse.
>
> If only write was working slower, now everything connected with cgroups
> is hardly working.
>
> Could it be connected with synchronize_rcu()?
I'd profile it with perf, and expect to find a large pile of cycles.
> Hanging on read():
>
> # strace -ttT cat /proc/cgroups
>
> 17:30:43.825005 fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 13), ...}) = 0 <0.000005>
> 17:30:43.825048 open("/proc/cgroups", O_RDONLY) = 3 <0.000014>
> 17:30:43.825085 fstat(3, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0 <0.000004>
> 17:30:43.825125 fadvise64(3, 0, 0, POSIX_FADV_SEQUENTIAL) = 0 <0.000005>
> 17:30:43.825161 read(3, "#subsys_name\thierarchy\tnum_cgrou"..., 32768) = 112 <7.447084>
Ew.. zillion cgroups is definitely a bad idea.
-Mike
next prev parent reply other threads:[~2012-07-25 13:57 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-19 18:58 Attaching a process to cgroups Alexey Vlasov
2012-06-20 3:34 ` Daisuke Nishimura
2012-06-20 11:08 ` Alexey Vlasov
2012-06-20 12:28 ` Mike Galbraith
2012-06-21 7:54 ` Alexey Vlasov
2012-06-21 8:23 ` Mike Galbraith
2012-06-21 8:26 ` Mike Galbraith
2012-06-26 18:06 ` Paul E. McKenney
2012-06-27 7:23 ` Mike Galbraith
2012-06-27 17:10 ` Paul E. McKenney
2012-06-28 2:40 ` Mike Galbraith
2012-07-23 20:41 ` Andrea Righi
2012-07-24 1:19 ` Mike Galbraith
2012-07-25 13:36 ` Alexey Vlasov
2012-07-25 13:57 ` Mike Galbraith [this message]
2012-07-26 13:02 ` Alexey Vlasov
2012-07-26 14:44 ` Mike Galbraith
2012-08-08 16:40 ` Alexey Vlasov
2012-08-08 16:51 ` Paul E. McKenney
2012-08-10 9:53 ` Alexey Vlasov
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