From: Srikar Dronamraju <srikar@linux•vnet.ibm.com>
To: Mel Gorman <mgorman@techsingularity•net>
Cc: Andrew Morton <akpm@linux-foundation•org>,
Linux-MM <linux-mm@kvack•org>, Rik van Riel <riel@surriel•com>,
Vlastimil Babka <vbabka@suse•cz>,
Johannes Weiner <hannes@cmpxchg•org>,
Minchan Kim <minchan@kernel•org>,
Joonsoo Kim <iamjoonsoo.kim@lge•com>,
LKML <linux-kernel@vger•kernel.org>,
Michael Ellerman <mpe@ellerman•id.au>,
linuxppc-dev@lists•ozlabs.org,
Mahesh Salgaonkar <mahesh@linux•vnet.ibm.com>,
Hari Bathini <hbathini@linux•vnet.ibm.com>
Subject: Re: [PATCH 07/34] mm, vmscan: make kswapd reclaim in terms of nodes
Date: Wed, 31 Aug 2016 23:03:20 +0530 [thread overview]
Message-ID: <20160831173320.GA5851@linux.vnet.ibm.com> (raw)
In-Reply-To: <20160831084942.GX8119@techsingularity.net>
> mm, vmscan: Only allocate and reclaim from zones with pages managed by the buddy allocator
>
> Firmware Assisted Dump (FA_DUMP) on ppc64 reserves substantial amounts
> of memory when booting a secondary kernel. Srikar Dronamraju reported that
> multiple nodes may have no memory managed by the buddy allocator but still
> return true for populated_zone().
>
> Commit 1d82de618ddd ("mm, vmscan: make kswapd reclaim in terms of nodes")
> was reported to cause kswapd to spin at 100% CPU usage when fadump was
> enabled. The old code happened to deal with the situation of a populated
> node with zero free pages by co-incidence but the current code tries to
> reclaim populated zones without realising that is impossible.
>
> We cannot just convert populated_zone() as many existing users really
> need to check for present_pages. This patch introduces a managed_zone()
> helper and uses it in the few cases where it is critical that the check
> is made for managed pages -- zonelist constuction and page reclaim.
one nit
s/constuction/construction/
>
Verified that it works fine.
--
Thanks and Regards
Srikar Dronamraju
prev parent reply other threads:[~2016-08-31 17:33 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1467970510-21195-1-git-send-email-mgorman@techsingularity.net>
[not found] ` <1467970510-21195-8-git-send-email-mgorman@techsingularity.net>
2016-08-29 9:38 ` [PATCH 07/34] mm, vmscan: make kswapd reclaim in terms of nodes Srikar Dronamraju
2016-08-30 12:07 ` Mel Gorman
2016-08-30 14:25 ` Srikar Dronamraju
2016-08-30 15:00 ` Mel Gorman
2016-08-31 6:09 ` Srikar Dronamraju
2016-08-31 8:49 ` Mel Gorman
2016-08-31 11:09 ` Michal Hocko
2016-08-31 12:46 ` Mel Gorman
2016-08-31 17:33 ` Srikar Dronamraju [this message]
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