From: Peter Zijlstra <peterz@infradead.org>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: "Huang, Ying" <ying.huang@intel.com>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
David Hildenbrand <david@redhat.com>,
akpm@linux-foundation.org, wangkefeng.wang@huawei.com,
willy@infradead.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, John Hubbard <jhubbard@nvidia.com>
Subject: Re: [RFC PATCH] mm: support large folio numa balancing
Date: Fri, 17 Nov 2023 11:13:43 +0100 [thread overview]
Message-ID: <20231117101343.GH3818@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20231117100745.fnpijbk4xgmals3k@techsingularity.net>
On Fri, Nov 17, 2023 at 10:07:45AM +0000, Mel Gorman wrote:
> This leads into a generic problem with large anything with NUMA
> balancing -- false sharing. As it stands, THP can be false shared by
> threads if thread-local data is split within a THP range. In this case,
> the ideal would be the THP is migrated to the hottest node but such
> support doesn't exist. The same applies for folios. If not handled
> properly, a large folio of any type can ping-pong between nodes so just
> migrating because we can is not necessarily a good idea. The patch
> should cover a realistic case why this matters, why splitting the folio
> is not better and supporting data.
Would it make sense to have THP merging conditional on all (most?) pages
having the same node?
next prev parent reply other threads:[~2023-11-17 10:14 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-13 10:45 Baolin Wang
2023-11-13 10:53 ` David Hildenbrand
2023-11-13 12:10 ` Kefeng Wang
2023-11-13 13:01 ` Baolin Wang
2023-11-13 22:15 ` John Hubbard
2023-11-14 11:35 ` David Hildenbrand
2023-11-14 13:12 ` Kefeng Wang
2023-11-13 12:59 ` Baolin Wang
2023-11-13 14:49 ` David Hildenbrand
2023-11-14 10:53 ` Baolin Wang
2023-11-14 1:12 ` Huang, Ying
2023-11-14 11:11 ` Baolin Wang
2023-11-15 2:58 ` Huang, Ying
2023-11-17 10:07 ` Mel Gorman
2023-11-17 10:13 ` Peter Zijlstra [this message]
2023-11-17 16:04 ` Mel Gorman
2023-11-20 8:01 ` Baolin Wang
2023-11-15 10:46 ` David Hildenbrand
2023-11-15 10:47 ` David Hildenbrand
2023-11-20 3:28 ` Baolin Wang
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