Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v3
From: Mel Gorman
Date: Wed Nov 30 2016 - 03:56:13 EST
On Mon, Nov 28, 2016 at 12:00:41PM +0100, Vlastimil Babka wrote:
> > 1-socket 6 year old machine
> > 4.9.0-rc5 4.9.0-rc5
> > vanilla hopcpu-v3
> > Hmean send-64 87.47 ( 0.00%) 127.14 ( 45.36%)
> > Hmean send-128 174.36 ( 0.00%) 256.42 ( 47.06%)
> > Hmean send-256 347.52 ( 0.00%) 509.41 ( 46.59%)
> > Hmean send-1024 1363.03 ( 0.00%) 1991.54 ( 46.11%)
> > Hmean send-2048 2632.68 ( 0.00%) 3759.51 ( 42.80%)
> > Hmean send-3312 4123.19 ( 0.00%) 5873.28 ( 42.45%)
> > Hmean send-4096 5056.48 ( 0.00%) 7072.81 ( 39.88%)
> > Hmean send-8192 8784.22 ( 0.00%) 12143.92 ( 38.25%)
> > Hmean send-16384 15081.60 ( 0.00%) 19812.71 ( 31.37%)
> > Hmean recv-64 86.19 ( 0.00%) 126.59 ( 46.87%)
> > Hmean recv-128 173.93 ( 0.00%) 255.21 ( 46.73%)
> > Hmean recv-256 346.19 ( 0.00%) 506.72 ( 46.37%)
> > Hmean recv-1024 1358.28 ( 0.00%) 1980.03 ( 45.77%)
> > Hmean recv-2048 2623.45 ( 0.00%) 3729.35 ( 42.15%)
> > Hmean recv-3312 4108.63 ( 0.00%) 5831.47 ( 41.93%)
> > Hmean recv-4096 5037.25 ( 0.00%) 7021.59 ( 39.39%)
> > Hmean recv-8192 8762.32 ( 0.00%) 12072.44 ( 37.78%)
> > Hmean recv-16384 15042.36 ( 0.00%) 19690.14 ( 30.90%)
>
> That looks way much better than the "v1" RFC posting. Was it just because
> you stopped doing the "at first iteration, use migratetype as index", and
> initializing pindex UINT_MAX hits so much quicker, or was there something
> more subtle that I missed? There was no changelog between "v1" and "v2".
>
FYI, the LKP test robot reported the following so there is some
independent basis for picking this up.
---8<---
FYI, we noticed a +23.0% improvement of netperf.Throughput_Mbps due to
commit:
commit 79404c5a5c66481aa55c0cae685e49e0f44a0479 ("mm: page_alloc: High-order per-cpu page allocator")
https://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git mm-pagealloc-highorder-percpu-v3r1
--
Mel Gorman
SUSE Labs