All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dave Chinner <david@fromorbit.com>
To: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] vmscan: fix initial shrinker size handling
Date: Tue, 23 Aug 2011 09:22:57 +1000	[thread overview]
Message-ID: <20110822232257.GT3162@dastard> (raw)
In-Reply-To: <20110822101721.19462.63082.stgit@zurg>

On Mon, Aug 22, 2011 at 02:17:21PM +0300, Konstantin Khlebnikov wrote:
> Shrinker function can returns -1, it means it cannot do anything without a risk of deadlock.
> For example prune_super() do this if it cannot grab superblock refrence, even if nr_to_scan=0.
> Currenly we interpret this like ULONG_MAX size shrinker, evaluate total_scan according this,
> and next time this shrinker can get really big pressure. Let's skip such shrinkers instead.
> 
> Also make total_scan signed, otherwise check (total_scan < 0) below never works.

I've got a patch set I am going to post out today that makes this
irrelevant.

The patch set splits the shrinker api into 2 callbacks - a "count
objects" callback and an "scan objects" callback, getting rid of
this messy "pass nr-to_scan == 0 to count objects" wart altogether.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

WARNING: multiple messages have this Message-ID (diff)
From: Dave Chinner <david@fromorbit.com>
To: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] vmscan: fix initial shrinker size handling
Date: Tue, 23 Aug 2011 09:22:57 +1000	[thread overview]
Message-ID: <20110822232257.GT3162@dastard> (raw)
In-Reply-To: <20110822101721.19462.63082.stgit@zurg>

On Mon, Aug 22, 2011 at 02:17:21PM +0300, Konstantin Khlebnikov wrote:
> Shrinker function can returns -1, it means it cannot do anything without a risk of deadlock.
> For example prune_super() do this if it cannot grab superblock refrence, even if nr_to_scan=0.
> Currenly we interpret this like ULONG_MAX size shrinker, evaluate total_scan according this,
> and next time this shrinker can get really big pressure. Let's skip such shrinkers instead.
> 
> Also make total_scan signed, otherwise check (total_scan < 0) below never works.

I've got a patch set I am going to post out today that makes this
irrelevant.

The patch set splits the shrinker api into 2 callbacks - a "count
objects" callback and an "scan objects" callback, getting rid of
this messy "pass nr-to_scan == 0 to count objects" wart altogether.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

--
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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  parent reply	other threads:[~2011-08-22 23:23 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-22 11:17 [PATCH 1/2] vmscan: fix initial shrinker size handling Konstantin Khlebnikov
2011-08-22 11:17 ` Konstantin Khlebnikov
2011-08-22 11:17 ` [PATCH 2/2] vmscan: use atomic-long for shrinker batching Konstantin Khlebnikov
2011-08-22 11:17   ` Konstantin Khlebnikov
2011-08-22 21:39   ` Andrew Morton
2011-08-22 21:39     ` Andrew Morton
2011-08-22 23:26   ` Dave Chinner
2011-08-22 23:26     ` Dave Chinner
2011-08-23  6:56   ` Konstantin Khlebnikov
2011-08-23  6:56     ` Konstantin Khlebnikov
2011-08-22 21:30 ` [PATCH 1/2] vmscan: fix initial shrinker size handling Andrew Morton
2011-08-22 21:30   ` Andrew Morton
2011-08-22 23:28   ` Dave Chinner
2011-08-22 23:28     ` Dave Chinner
2011-08-23  6:47   ` Konstantin Khlebnikov
2011-08-23  6:47     ` Konstantin Khlebnikov
2011-08-22 23:22 ` Dave Chinner [this message]
2011-08-22 23:22   ` Dave Chinner
2011-08-22 23:38   ` Andrew Morton
2011-08-22 23:38     ` Andrew Morton
2011-08-23  0:00     ` Dave Chinner
2011-08-23  0:00       ` Dave Chinner
2011-09-13 18:38       ` Johannes Weiner
2011-09-13 18:38         ` Johannes Weiner
2011-10-05 21:52         ` Johannes Weiner
2011-10-05 21:52           ` Johannes Weiner
2011-10-05 21:58           ` Andrew Morton
2011-10-05 21:58             ` Andrew Morton

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=20110822232257.GT3162@dastard \
    --to=david@fromorbit.com \
    --cc=akpm@linux-foundation.org \
    --cc=khlebnikov@openvz.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.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.