All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mel Gorman <mgorman@techsingularity.net>
To: Pankaj Gupta <pagupta@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	akpm@linux-foundation.org, vbabka@suse.cz, riel@redhat.com,
	hannes@cmpxchg.org, iamjoonsoo.kim@lge.com,
	kirill.shutemov@linux.intel.com, izumi.taku@jp.fujitsu.com
Subject: Re: [PATCH] mm: Add WARN_ON for possibility of infinite loop if empty lists in free_pcppages_bulk'
Date: Fri, 19 Aug 2016 13:45:08 +0100	[thread overview]
Message-ID: <20160819124508.GM8119@techsingularity.net> (raw)
In-Reply-To: <1471608918-5101-1-git-send-email-pagupta@redhat.com>

On Fri, Aug 19, 2016 at 05:45:18PM +0530, Pankaj Gupta wrote:
> While debugging issue in realtime kernel i found a scenario
> which resulted in infinite loop resulting because of empty pcp->lists
> and valid 'to_free' value. This patch is to add 'WARN_ON' in function
> 'free_pcppages_bulk' if there is possibility of infinite loop because 
> of any bug in code.
> 

What was the bug that allowed this situation to occur? It would imply
the pcp count was somehow out of sync.

-- 
Mel Gorman
SUSE Labs

--
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>

WARNING: multiple messages have this Message-ID (diff)
From: Mel Gorman <mgorman@techsingularity.net>
To: Pankaj Gupta <pagupta@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	akpm@linux-foundation.org, vbabka@suse.cz, riel@redhat.com,
	hannes@cmpxchg.org, iamjoonsoo.kim@lge.com,
	kirill.shutemov@linux.intel.com, izumi.taku@jp.fujitsu.com
Subject: Re: [PATCH] mm: Add WARN_ON for possibility of infinite loop if empty lists in free_pcppages_bulk'
Date: Fri, 19 Aug 2016 13:45:08 +0100	[thread overview]
Message-ID: <20160819124508.GM8119@techsingularity.net> (raw)
In-Reply-To: <1471608918-5101-1-git-send-email-pagupta@redhat.com>

On Fri, Aug 19, 2016 at 05:45:18PM +0530, Pankaj Gupta wrote:
> While debugging issue in realtime kernel i found a scenario
> which resulted in infinite loop resulting because of empty pcp->lists
> and valid 'to_free' value. This patch is to add 'WARN_ON' in function
> 'free_pcppages_bulk' if there is possibility of infinite loop because 
> of any bug in code.
> 

What was the bug that allowed this situation to occur? It would imply
the pcp count was somehow out of sync.

-- 
Mel Gorman
SUSE Labs

  reply	other threads:[~2016-08-19 12:45 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-19 12:15 [PATCH] mm: Add WARN_ON for possibility of infinite loop if empty lists in free_pcppages_bulk' Pankaj Gupta
2016-08-19 12:15 ` Pankaj Gupta
2016-08-19 12:45 ` Mel Gorman [this message]
2016-08-19 12:45   ` Mel Gorman
2016-08-19 13:07   ` Pankaj Gupta
2016-08-19 13:07     ` Pankaj Gupta
2016-08-19 14:00     ` Mel Gorman
2016-08-19 14:00       ` Mel Gorman
2016-08-23  8:48       ` Pankaj Gupta
2016-08-23  8:48         ` Pankaj Gupta

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=20160819124508.GM8119@techsingularity.net \
    --to=mgorman@techsingularity.net \
    --cc=akpm@linux-foundation.org \
    --cc=hannes@cmpxchg.org \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=izumi.taku@jp.fujitsu.com \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=pagupta@redhat.com \
    --cc=riel@redhat.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 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.