From: Shakeel Butt <shakeelb@google.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>,
Johannes Weiner <hannes@cmpxchg.org>,
Roman Gushchin <guro@fb.com>, Michal Hocko <mhocko@kernel.org>,
Minchan Kim <minchan@kernel.org>, Rik van Riel <riel@surriel.com>,
Linux MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm: fix LRU balancing effect of new transparent huge pages
Date: Mon, 11 May 2020 14:38:23 -0700 [thread overview]
Message-ID: <CALvZod7848_BETonZJFxXN1n1E7KtZ4DzT1-BeaN6hvBysN8WQ@mail.gmail.com> (raw)
In-Reply-To: <20200511141122.9b03e2f0852b57b224eab066@linux-foundation.org>
On Mon, May 11, 2020 at 2:11 PM Andrew Morton <akpm@linux-foundation.org> wrote:
>
> On Sat, 9 May 2020 07:19:46 -0700 Shakeel Butt <shakeelb@google.com> wrote:
>
> > Currently, THP are counted as single pages until they are split right
> > before being swapped out. However, at that point the VM is already in
> > the middle of reclaim, and adjusting the LRU balance then is useless.
> >
> > Always account THP by the number of basepages, and remove the fixup
> > from the splitting path.
>
> Confused. What kernel is this applicable to?
It is still applicable to the latest Linux kernel. Basically
lruvec->reclaim_stat->recent_[scanned|rotated] counters are used as
heuristic in get_scan_count() to measure how much file and anon LRUs
should be scanned by the current reclaim. Previously huge pages are
treated as single page while updating the recent_[scanned|rotated]
counters in swap.c while vmscan.c correctly updates them as huge
pages.
next prev parent reply other threads:[~2020-05-11 21:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-09 14:19 [PATCH] mm: fix LRU balancing effect of new transparent huge pages Shakeel Butt
2020-05-11 21:11 ` Andrew Morton
2020-05-11 21:38 ` Shakeel Butt [this message]
2020-05-11 21:58 ` Andrew Morton
2020-05-11 22:04 ` Shakeel Butt
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