linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: Petr Mladek <pmladek@suse.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	David Rientjes <rientjes@google.com>,
	Ebru Akagunduz <ebru.akagunduz@gmail.com>,
	Mel Gorman <mgorman@suse.de>,
	linux-mm@kvack.org, linux-pm@vger.kernel.org,
	Jiri Kosina <jkosina@suse.cz>
Subject: Re: [PATCH] mm/khugepaged: Allow to interrupt allocation sleep again
Date: Mon, 24 Aug 2015 13:30:43 -0700	[thread overview]
Message-ID: <20150824133043.23b66633b5c9c91bd6aae190@linux-foundation.org> (raw)
In-Reply-To: <1440429203-4039-1-git-send-email-pmladek@suse.com>

On Mon, 24 Aug 2015 17:13:23 +0200 Petr Mladek <pmladek@suse.com> wrote:

> The commit 1dfb059b9438633b0546 ("thp: reduce khugepaged freezing
> latency") fixed khugepaged to do not block a system suspend. But
> the result is that it could not get interrupted before the given
> timeout because the condition for the wait event is "false".

What are the userspace-visible effects of this bug?

> This patch puts back the original approach but it uses
> freezable_schedule_timeout_interruptible() instead of
> schedule_timeout_interruptible(). It does the right thing.
> I am pretty sure that the freezable variant was not used in
> the original fix only because it was not available at that time.
> 
> The regression has been there for ages. It was not critical. It just
> did the allocation throttling a little bit more aggressively.
> 
> I found this problem when converting the kthread to kthread worker API
> and trying to understand the code.
> 
> ...

--
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/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  reply	other threads:[~2015-08-24 20:30 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-24 15:13 [PATCH] mm/khugepaged: Allow to interrupt allocation sleep again Petr Mladek
2015-08-24 20:30 ` Andrew Morton [this message]
2015-08-25  8:42   ` Petr Mladek
2015-08-25  9:12     ` Vlastimil Babka
2015-08-25  9:08 ` Vlastimil Babka

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=20150824133043.23b66633b5c9c91bd6aae190@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=aarcange@redhat.com \
    --cc=aneesh.kumar@linux.vnet.ibm.com \
    --cc=ebru.akagunduz@gmail.com \
    --cc=jkosina@suse.cz \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=linux-mm@kvack.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=mgorman@suse.de \
    --cc=pmladek@suse.com \
    --cc=rientjes@google.com \
    --cc=vbabka@suse.cz \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).