From: Matt Fleming <matt@codeblueprint.co.uk>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.com>, Vlastimil Babka <vbabka@suse.cz>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>, Linux-MM <linux-mm@kvack.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 0/3] Recalculate per-cpu page allocator batch and high limits after deferred meminit
Date: Fri, 18 Oct 2019 12:58:49 +0100 [thread overview]
Message-ID: <20191018115849.GH4065@codeblueprint.co.uk> (raw)
In-Reply-To: <20191018105606.3249-1-mgorman@techsingularity.net>
On Fri, 18 Oct, at 11:56:03AM, Mel Gorman wrote:
> A private report stated that system CPU usage was excessive on an AMD
> EPYC 2 machine while building kernels with much longer build times than
> expected. The issue is partially explained by high zone lock contention
> due to the per-cpu page allocator batch and high limits being calculated
> incorrectly. This series addresses a large chunk of the problem. Patch 1
> is mostly cosmetic but prepares for patch 2 which is the real fix. Patch
> 3 is definiely cosmetic but was noticed while implementing the fix. Proper
> details are in the changelog for patch 2.
>
> include/linux/mm.h | 3 ---
> mm/internal.h | 3 +++
> mm/page_alloc.c | 33 ++++++++++++++++++++-------------
> 3 files changed, 23 insertions(+), 16 deletions(-)
Just to confirm, these patches don't fix the issue we're seeing on the
EPYC 2 machines, but they do return the batch sizes to sensible values.
next prev parent reply other threads:[~2019-10-18 11:58 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-18 10:56 Mel Gorman
2019-10-18 10:56 ` [PATCH 1/3] mm, pcp: Share common code between memory hotplug and percpu sysctl handler Mel Gorman
2019-10-18 11:57 ` Matt Fleming
2019-10-18 12:51 ` Michal Hocko
2019-10-18 10:56 ` [PATCH 2/3] mm, meminit: Recalculate pcpu batch and high limits after init completes Mel Gorman
2019-10-18 11:57 ` Matt Fleming
2019-10-18 13:01 ` Michal Hocko
2019-10-18 14:09 ` Mel Gorman
2019-10-19 1:40 ` Andrew Morton
2019-10-20 9:32 ` Mel Gorman
2019-10-18 10:56 ` [PATCH 3/3] mm, pcpu: Make zone pcp updates and reset internal to the mm Mel Gorman
2019-10-18 11:57 ` Matt Fleming
2019-10-18 13:02 ` Michal Hocko
2019-10-18 11:58 ` Matt Fleming [this message]
2019-10-18 12:54 ` [PATCH 0/3] Recalculate per-cpu page allocator batch and high limits after deferred meminit Mel Gorman
2019-10-18 14:48 ` Matt Fleming
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