From: Fengguang Wu <fengguang.wu@intel.com>
To: lkp@lists.01.org
Subject: Re: increased vmap_area_lock contentions on "n_tty: Move buffers into n_tty_data"
Date: Tue, 17 Sep 2013 10:56:42 +0800 [thread overview]
Message-ID: <20130917025642.GA29664@localhost> (raw)
In-Reply-To: <5237C183.7040308@hurleysoftware.com>
[-- Attachment #1: Type: text/plain, Size: 1021 bytes --]
On Mon, Sep 16, 2013 at 10:42:11PM -0400, Peter Hurley wrote:
> On 09/12/2013 11:38 PM, Fengguang Wu wrote:
> >On Thu, Sep 12, 2013 at 08:17:00PM -0700, Greg KH wrote:
> >>On Fri, Sep 13, 2013 at 08:51:33AM +0800, Fengguang Wu wrote:
> >>>Hi Peter,
> >>>
> >>>FYI, we noticed much increased vmap_area_lock contentions since this
> >>>commit:
> >>
> >>What does that mean? What is happening, are we allocating/removing more
> >>memory now?
> >
> >// leave this question to Peter and Tejun. :)
> >
> >>What type of load were you running that showed this problem?
> >
> >The increased contentions and lock hold/wait time showed up in a
> >number of test cases.
>
> How is the raw data acquired?
>
> For example, is the test apparatus reading from /proc/vmallocinfo
> (which claims the vmap_area_lock) during the test execution?
We didn't read /proc/vmallocinfo and read /proc/lock_stat once when
the test ends.
> I'm wondering if a Heisenberg effect is happening here.
Thanks,
Fengguang
WARNING: multiple messages have this Message-ID (diff)
From: Fengguang Wu <fengguang.wu@intel.com>
To: Peter Hurley <peter@hurleysoftware.com>
Cc: Greg KH <gregkh@linuxfoundation.org>,
LKML <linux-kernel@vger.kernel.org>,
lkp@01.org, Tejun Heo <tj@kernel.org>
Subject: Re: increased vmap_area_lock contentions on "n_tty: Move buffers into n_tty_data"
Date: Tue, 17 Sep 2013 10:56:42 +0800 [thread overview]
Message-ID: <20130917025642.GA29664@localhost> (raw)
In-Reply-To: <5237C183.7040308@hurleysoftware.com>
On Mon, Sep 16, 2013 at 10:42:11PM -0400, Peter Hurley wrote:
> On 09/12/2013 11:38 PM, Fengguang Wu wrote:
> >On Thu, Sep 12, 2013 at 08:17:00PM -0700, Greg KH wrote:
> >>On Fri, Sep 13, 2013 at 08:51:33AM +0800, Fengguang Wu wrote:
> >>>Hi Peter,
> >>>
> >>>FYI, we noticed much increased vmap_area_lock contentions since this
> >>>commit:
> >>
> >>What does that mean? What is happening, are we allocating/removing more
> >>memory now?
> >
> >// leave this question to Peter and Tejun. :)
> >
> >>What type of load were you running that showed this problem?
> >
> >The increased contentions and lock hold/wait time showed up in a
> >number of test cases.
>
> How is the raw data acquired?
>
> For example, is the test apparatus reading from /proc/vmallocinfo
> (which claims the vmap_area_lock) during the test execution?
We didn't read /proc/vmallocinfo and read /proc/lock_stat once when
the test ends.
> I'm wondering if a Heisenberg effect is happening here.
Thanks,
Fengguang
next prev parent reply other threads:[~2013-09-17 2:56 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-13 0:51 increased vmap_area_lock contentions on "n_tty: Move buffers into n_tty_data" Fengguang Wu
2013-09-13 0:51 ` Fengguang Wu
2013-09-13 1:09 ` Fengguang Wu
2013-09-13 1:09 ` Fengguang Wu
2013-09-17 15:34 ` Peter Hurley
2013-09-17 15:34 ` Peter Hurley
2013-09-17 23:22 ` Fengguang Wu
2013-09-17 23:22 ` Fengguang Wu
2013-09-18 0:22 ` Peter Hurley
2013-09-18 0:22 ` Peter Hurley
2013-09-25 9:04 ` Lin Ming
2013-09-25 9:04 ` Lin Ming
2013-09-25 11:30 ` Peter Hurley
2013-09-25 11:30 ` Peter Hurley
2013-09-25 14:53 ` Lin Ming
2013-09-25 14:53 ` Lin Ming
2013-09-25 16:02 ` Lin Ming
2013-09-25 16:02 ` Lin Ming
2013-09-26 3:20 ` Andi Kleen
2013-09-26 3:20 ` Andi Kleen
2013-09-26 11:52 ` Peter Hurley
2013-09-26 11:52 ` Peter Hurley
2013-09-26 15:32 ` Andi Kleen
2013-09-26 15:32 ` Andi Kleen
2013-09-26 17:22 ` Peter Hurley
2013-09-26 17:22 ` Peter Hurley
2013-09-26 7:33 ` Andrew Morton
2013-09-26 7:33 ` Andrew Morton
2013-09-26 11:31 ` Peter Hurley
2013-09-26 11:31 ` Peter Hurley
2013-09-26 15:04 ` Greg KH
2013-09-26 15:04 ` Greg KH
2013-09-26 17:35 ` Peter Hurley
2013-09-26 17:35 ` Peter Hurley
2013-09-26 18:05 ` Andrew Morton
2013-09-26 18:05 ` Andrew Morton
2013-09-26 21:42 ` Peter Hurley
2013-09-26 21:42 ` Peter Hurley
2013-09-26 21:58 ` Andrew Morton
2013-09-26 21:58 ` Andrew Morton
2013-09-26 22:21 ` Peter Hurley
2013-09-26 22:21 ` Peter Hurley
2013-09-18 0:49 ` Peter Hurley
2013-09-18 0:49 ` Peter Hurley
2013-09-13 3:17 ` Greg KH
2013-09-13 3:17 ` Greg KH
2013-09-13 3:38 ` Fengguang Wu
2013-09-13 3:38 ` Fengguang Wu
2013-09-13 3:44 ` Greg KH
2013-09-13 3:44 ` Greg KH
2013-09-13 9:55 ` Peter Hurley
2013-09-13 9:55 ` Peter Hurley
2013-09-13 12:34 ` Greg KH
2013-09-13 12:34 ` Greg KH
2013-09-17 2:42 ` Peter Hurley
2013-09-17 2:42 ` Peter Hurley
2013-09-17 2:56 ` Fengguang Wu [this message]
2013-09-17 2:56 ` Fengguang Wu
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