From: Peter Hurley <peter@hurleysoftware.com>
To: lkp@lists.01.org
Subject: Re: increased vmap_area_lock contentions on "n_tty: Move buffers into n_tty_data"
Date: Wed, 25 Sep 2013 07:30:40 -0400 [thread overview]
Message-ID: <5242C960.7050506@hurleysoftware.com> (raw)
In-Reply-To: <CAF1ivSbYg296oHhO0_UXwkos8Ui_1C93pUnXPzow4qLWyAa2kg@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 672 bytes --]
On 09/25/2013 05:04 AM, Lin Ming wrote:
> On Wed, Sep 18, 2013 at 8:22 AM, Peter Hurley <peter@hurleysoftware.com> wrote:
> [snip]
>>
>> Looking over vmalloc.c, the critical section footprint of the vmap_area_lock
>> could definitely be reduced (even nearly eliminated), but that's a project
>> for
>> another day :)
>
> Hi Peter,
>
> I also looked over vmallo.c, but didn't find obvious way to reduce the
> critical section footprint.
> Could you share some hints how to do this?
vmap_area_list is an RCU list.
get_vmalloc_info() doesn't need to take the vmap_area_lock at all.
Look at __purge_vmap_area_lazy() for a howto.
Regards,
Peter Hurley
WARNING: multiple messages have this Message-ID (diff)
From: Peter Hurley <peter@hurleysoftware.com>
To: Lin Ming <minggr@gmail.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>,
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: Wed, 25 Sep 2013 07:30:40 -0400 [thread overview]
Message-ID: <5242C960.7050506@hurleysoftware.com> (raw)
In-Reply-To: <CAF1ivSbYg296oHhO0_UXwkos8Ui_1C93pUnXPzow4qLWyAa2kg@mail.gmail.com>
On 09/25/2013 05:04 AM, Lin Ming wrote:
> On Wed, Sep 18, 2013 at 8:22 AM, Peter Hurley <peter@hurleysoftware.com> wrote:
> [snip]
>>
>> Looking over vmalloc.c, the critical section footprint of the vmap_area_lock
>> could definitely be reduced (even nearly eliminated), but that's a project
>> for
>> another day :)
>
> Hi Peter,
>
> I also looked over vmallo.c, but didn't find obvious way to reduce the
> critical section footprint.
> Could you share some hints how to do this?
vmap_area_list is an RCU list.
get_vmalloc_info() doesn't need to take the vmap_area_lock at all.
Look at __purge_vmap_area_lazy() for a howto.
Regards,
Peter Hurley
next prev parent reply other threads:[~2013-09-25 11:30 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 [this message]
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
2013-09-17 2:56 ` Fengguang Wu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5242C960.7050506@hurleysoftware.com \
--to=peter@hurleysoftware.com \
--cc=lkp@lists.01.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.