From: Mel Gorman <mgorman@techsingularity.net>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>, Peter Zijlstra <peterz@infradead.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org
Subject: Re: Hackbench pipes regression bisected to PSI
Date: Mon, 26 Nov 2018 23:29:26 +0000 [thread overview]
Message-ID: <20181126232926.GS23260@techsingularity.net> (raw)
In-Reply-To: <20181126173218.GA22640@cmpxchg.org>
On Mon, Nov 26, 2018 at 12:32:18PM -0500, Johannes Weiner wrote:
> >
> > Bit late to notice but this switch should be in
> > Documentation/admin-guide/kernel-parameters.txt. If you really want to
> > match the automatic numa balancing switch then it also should be
> > psi=[enable|disable] instead of psi_enable=[1|0]
>
> Done and done, thanks. Updated patch:
>
The following is a comparision using CONFIG_PSI=n as a baseline against
your patch and a vanilla kernel
4.20.0-rc4 4.20.0-rc4 4.20.0-rc4
kconfigdisable-v1r1 vanilla psidisable-v1r1
Amean 1 1.3100 ( 0.00%) 1.3923 ( -6.28%) 1.3427 ( -2.49%)
Amean 3 3.8860 ( 0.00%) 4.1230 * -6.10%* 3.8860 ( -0.00%)
Amean 5 6.8847 ( 0.00%) 8.0390 * -16.77%* 6.7727 ( 1.63%)
Amean 7 9.9310 ( 0.00%) 10.8367 * -9.12%* 9.9910 ( -0.60%)
Amean 12 16.6577 ( 0.00%) 18.2363 * -9.48%* 17.1083 ( -2.71%)
Amean 18 26.5133 ( 0.00%) 27.8833 * -5.17%* 25.7663 ( 2.82%)
Amean 24 34.3003 ( 0.00%) 34.6830 ( -1.12%) 32.0450 ( 6.58%)
Amean 30 40.0063 ( 0.00%) 40.5800 ( -1.43%) 41.5087 ( -3.76%)
Amean 32 40.1407 ( 0.00%) 41.2273 ( -2.71%) 39.9417 ( 0.50%)
It's showing that the vanilla kernel takes a hit (as the bisection
indicated it would) and that disabling PSI by default is reasonably
close in terms of performance for this particular workload on this
particular machine so;
Tested-by: Mel Gorman <mgorman@techsingularity.net>
Thanks!
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2018-11-26 23:29 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-26 13:34 Hackbench pipes regression bisected to PSI Mel Gorman
2018-11-26 13:34 ` Mel Gorman
2018-11-26 16:07 ` Johannes Weiner
2018-11-26 16:07 ` Johannes Weiner
2018-11-26 16:54 ` Mel Gorman
2018-11-26 17:32 ` Johannes Weiner
2018-11-26 17:32 ` Johannes Weiner
2018-11-26 17:44 ` Mel Gorman
2018-11-26 23:29 ` Mel Gorman [this message]
2018-11-27 16:46 ` Johannes Weiner
2018-11-27 16:46 ` Johannes Weiner
2018-11-27 16:53 ` Johannes Weiner
2018-11-27 16:53 ` Johannes Weiner
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