From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>, Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
brouer@redhat.com,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH 00/28] Optimise page alloc/free fast paths v3
Date: Fri, 15 Apr 2016 14:44:02 +0200 [thread overview]
Message-ID: <20160415144402.5fbe7a1e@redhat.com> (raw)
In-Reply-To: <1460710760-32601-1-git-send-email-mgorman@techsingularity.net>
On Fri, 15 Apr 2016 09:58:52 +0100
Mel Gorman <mgorman@techsingularity.net> wrote:
> There were no further responses to the last series but I kept going and
> added a few more small bits. Most are basic micro-optimisations. The last
> two patches weaken debugging checks to improve performance at the cost of
> delayed detection of some use-after-free and memory corruption bugs. If
> they make people uncomfortable, they can be dropped and the rest of the
> series stands on its own.
>
> Changelog since v2
> o Add more micro-optimisations
> o Weak debugging checks in favor of speed
>
[...]
>
> The overall impact on a page allocator microbenchmark for a range of orders
I also micro benchmarked this patchset. Avail via Mel Gorman's kernel tree:
http://git.kernel.org/cgit/linux/kernel/git/mel/linux.git
tested branch mm-vmscan-node-lru-v5r9 which also contain the node-lru series.
Tool:
https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/mm/bench/page_bench01.c
Run as:
modprobe page_bench01; rmmod page_bench01 ; dmesg | tail -n40 | grep 'alloc_pages order'
Results kernel 4.6.0-rc1 :
alloc_pages order:0(4096B/x1) 272 cycles per-4096B 272 cycles
alloc_pages order:1(8192B/x2) 395 cycles per-4096B 197 cycles
alloc_pages order:2(16384B/x4) 433 cycles per-4096B 108 cycles
alloc_pages order:3(32768B/x8) 503 cycles per-4096B 62 cycles
alloc_pages order:4(65536B/x16) 682 cycles per-4096B 42 cycles
alloc_pages order:5(131072B/x32) 910 cycles per-4096B 28 cycles
alloc_pages order:6(262144B/x64) 1384 cycles per-4096B 21 cycles
alloc_pages order:7(524288B/x128) 2335 cycles per-4096B 18 cycles
alloc_pages order:8(1048576B/x256) 4108 cycles per-4096B 16 cycles
alloc_pages order:9(2097152B/x512) 8398 cycles per-4096B 16 cycles
After Mel Gorman's optimizations, results from mm-vmscan-node-lru-v5r::
alloc_pages order:0(4096B/x1) 231 cycles per-4096B 231 cycles
alloc_pages order:1(8192B/x2) 351 cycles per-4096B 175 cycles
alloc_pages order:2(16384B/x4) 357 cycles per-4096B 89 cycles
alloc_pages order:3(32768B/x8) 397 cycles per-4096B 49 cycles
alloc_pages order:4(65536B/x16) 481 cycles per-4096B 30 cycles
alloc_pages order:5(131072B/x32) 652 cycles per-4096B 20 cycles
alloc_pages order:6(262144B/x64) 1054 cycles per-4096B 16 cycles
alloc_pages order:7(524288B/x128) 1852 cycles per-4096B 14 cycles
alloc_pages order:8(1048576B/x256) 3156 cycles per-4096B 12 cycles
alloc_pages order:9(2097152B/x512) 6790 cycles per-4096B 13 cycles
I've also started doing some parallel concurrency testing workloads[1]
[1] https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/mm/bench/page_bench03.c
Order-0 pages scale nicely:
Results kernel 4.6.0-rc1 :
Parallel-CPUs:1 page order:0(4096B/x1) ave 274 cycles per-4096B 274 cycles
Parallel-CPUs:2 page order:0(4096B/x1) ave 283 cycles per-4096B 283 cycles
Parallel-CPUs:3 page order:0(4096B/x1) ave 284 cycles per-4096B 284 cycles
Parallel-CPUs:4 page order:0(4096B/x1) ave 288 cycles per-4096B 288 cycles
Parallel-CPUs:5 page order:0(4096B/x1) ave 417 cycles per-4096B 417 cycles
Parallel-CPUs:6 page order:0(4096B/x1) ave 503 cycles per-4096B 503 cycles
Parallel-CPUs:7 page order:0(4096B/x1) ave 567 cycles per-4096B 567 cycles
Parallel-CPUs:8 page order:0(4096B/x1) ave 620 cycles per-4096B 620 cycles
And even better with you changes! :-))) This is great work!
Results from mm-vmscan-node-lru-v5r:
Parallel-CPUs:1 page order:0(4096B/x1) ave 246 cycles per-4096B 246 cycles
Parallel-CPUs:2 page order:0(4096B/x1) ave 251 cycles per-4096B 251 cycles
Parallel-CPUs:3 page order:0(4096B/x1) ave 254 cycles per-4096B 254 cycles
Parallel-CPUs:4 page order:0(4096B/x1) ave 258 cycles per-4096B 258 cycles
Parallel-CPUs:5 page order:0(4096B/x1) ave 313 cycles per-4096B 313 cycles
Parallel-CPUs:6 page order:0(4096B/x1) ave 369 cycles per-4096B 369 cycles
Parallel-CPUs:7 page order:0(4096B/x1) ave 379 cycles per-4096B 379 cycles
Parallel-CPUs:8 page order:0(4096B/x1) ave 399 cycles per-4096B 399 cycles
It does not seem that higher order page scale... and your patches does
not change this pattern.
Example order-3 pages, which is often used in the network stack:
Results kernel 4.6.0-rc1 ::
Parallel-CPUs:1 page order:3(32768B/x8) ave 524 cycles per-4096B 65 cycles
Parallel-CPUs:2 page order:3(32768B/x8) ave 2131 cycles per-4096B 266 cycles
Parallel-CPUs:3 page order:3(32768B/x8) ave 3885 cycles per-4096B 485 cycles
Parallel-CPUs:4 page order:3(32768B/x8) ave 4520 cycles per-4096B 565 cycles
Parallel-CPUs:5 page order:3(32768B/x8) ave 5604 cycles per-4096B 700 cycles
Parallel-CPUs:6 page order:3(32768B/x8) ave 7125 cycles per-4096B 890 cycles
Parallel-CPUs:7 page order:3(32768B/x8) ave 7883 cycles per-4096B 985 cycles
Parallel-CPUs:8 page order:3(32768B/x8) ave 9364 cycles per-4096B 1170 cycles
Results from mm-vmscan-node-lru-v5r:
Parallel-CPUs:1 page order:3(32768B/x8) ave 421 cycles per-4096B 52 cycles
Parallel-CPUs:2 page order:3(32768B/x8) ave 2236 cycles per-4096B 279 cycles
Parallel-CPUs:3 page order:3(32768B/x8) ave 3408 cycles per-4096B 426 cycles
Parallel-CPUs:4 page order:3(32768B/x8) ave 4687 cycles per-4096B 585 cycles
Parallel-CPUs:5 page order:3(32768B/x8) ave 5972 cycles per-4096B 746 cycles
Parallel-CPUs:6 page order:3(32768B/x8) ave 7349 cycles per-4096B 918 cycles
Parallel-CPUs:7 page order:3(32768B/x8) ave 8436 cycles per-4096B 1054 cycles
Parallel-CPUs:8 page order:3(32768B/x8) ave 9589 cycles per-4096B 1198 cycles
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
Author of http://www.iptv-analyzer.org
LinkedIn: http://www.linkedin.com/in/brouer
https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/mm/bench/page_bench03.c
for ORDER in $(seq 0 5) ; do \
for X in $(seq 1 8) ; do \
modprobe page_bench03 page_order=$ORDER parallel_cpus=$X run_flags=$((2#100)); \
rmmod page_bench03 ; dmesg | tail -n 3 | grep Parallel-CPUs ; \
done; \
done
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2016-04-15 12:44 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-15 8:58 [PATCH 00/28] Optimise page alloc/free fast paths v3 Mel Gorman
2016-04-15 8:58 ` [PATCH 01/28] mm, page_alloc: Only check PageCompound for high-order pages Mel Gorman
2016-04-25 9:33 ` Vlastimil Babka
2016-04-26 10:33 ` Mel Gorman
2016-04-26 11:20 ` Vlastimil Babka
2016-04-15 8:58 ` [PATCH 02/28] mm, page_alloc: Use new PageAnonHead helper in the free page fast path Mel Gorman
2016-04-25 9:56 ` Vlastimil Babka
2016-04-15 8:58 ` [PATCH 03/28] mm, page_alloc: Reduce branches in zone_statistics Mel Gorman
2016-04-25 11:15 ` Vlastimil Babka
2016-04-15 8:58 ` [PATCH 04/28] mm, page_alloc: Inline zone_statistics Mel Gorman
2016-04-25 11:17 ` Vlastimil Babka
2016-04-15 8:58 ` [PATCH 05/28] mm, page_alloc: Inline the fast path of the zonelist iterator Mel Gorman
2016-04-25 14:50 ` Vlastimil Babka
2016-04-26 10:30 ` Mel Gorman
2016-04-26 11:05 ` Vlastimil Babka
2016-04-15 8:58 ` [PATCH 06/28] mm, page_alloc: Use __dec_zone_state for order-0 page allocation Mel Gorman
2016-04-26 11:25 ` Vlastimil Babka
2016-04-15 8:58 ` [PATCH 07/28] mm, page_alloc: Avoid unnecessary zone lookups during pageblock operations Mel Gorman
2016-04-26 11:29 ` Vlastimil Babka
2016-04-15 8:59 ` [PATCH 08/28] mm, page_alloc: Convert alloc_flags to unsigned Mel Gorman
2016-04-26 11:31 ` Vlastimil Babka
2016-04-15 8:59 ` [PATCH 09/28] mm, page_alloc: Convert nr_fair_skipped to bool Mel Gorman
2016-04-26 11:37 ` Vlastimil Babka
2016-04-15 8:59 ` [PATCH 10/28] mm, page_alloc: Remove unnecessary local variable in get_page_from_freelist Mel Gorman
2016-04-26 11:38 ` Vlastimil Babka
2016-04-15 8:59 ` [PATCH 11/28] mm, page_alloc: Remove unnecessary initialisation " Mel Gorman
2016-04-26 11:39 ` Vlastimil Babka
2016-04-15 9:07 ` [PATCH 13/28] mm, page_alloc: Remove redundant check for empty zonelist Mel Gorman
2016-04-15 9:07 ` [PATCH 14/28] mm, page_alloc: Simplify last cpupid reset Mel Gorman
2016-04-26 13:30 ` Vlastimil Babka
2016-04-15 9:07 ` [PATCH 15/28] mm, page_alloc: Move might_sleep_if check to the allocator slowpath Mel Gorman
2016-04-26 13:41 ` Vlastimil Babka
2016-04-26 14:50 ` Mel Gorman
2016-04-26 15:16 ` Vlastimil Babka
2016-04-26 16:29 ` Mel Gorman
2016-04-15 9:07 ` [PATCH 16/28] mm, page_alloc: Move __GFP_HARDWALL modifications out of the fastpath Mel Gorman
2016-04-26 14:13 ` Vlastimil Babka
2016-04-15 9:07 ` [PATCH 17/28] mm, page_alloc: Check once if a zone has isolated pageblocks Mel Gorman
2016-04-26 14:27 ` Vlastimil Babka
2016-04-15 9:07 ` [PATCH 18/28] mm, page_alloc: Shorten the page allocator fast path Mel Gorman
2016-04-26 15:23 ` Vlastimil Babka
2016-04-15 9:07 ` [PATCH 19/28] mm, page_alloc: Reduce cost of fair zone allocation policy retry Mel Gorman
2016-04-26 17:24 ` Vlastimil Babka
2016-04-15 9:07 ` [PATCH 20/28] mm, page_alloc: Shortcut watermark checks for order-0 pages Mel Gorman
2016-04-26 17:32 ` Vlastimil Babka
2016-04-15 9:07 ` [PATCH 21/28] mm, page_alloc: Avoid looking up the first zone in a zonelist twice Mel Gorman
2016-04-26 17:46 ` Vlastimil Babka
2016-04-15 9:07 ` [PATCH 22/28] mm, page_alloc: Remove field from alloc_context Mel Gorman
2016-04-15 9:07 ` [PATCH 23/28] mm, page_alloc: Check multiple page fields with a single branch Mel Gorman
2016-04-26 18:41 ` Vlastimil Babka
2016-04-27 10:07 ` Mel Gorman
2016-04-15 9:07 ` [PATCH 24/28] mm, page_alloc: Remove unnecessary variable from free_pcppages_bulk Mel Gorman
2016-04-26 18:43 ` Vlastimil Babka
2016-04-15 9:07 ` [PATCH 25/28] mm, page_alloc: Inline pageblock lookup in page free fast paths Mel Gorman
2016-04-26 19:10 ` Vlastimil Babka
2016-04-15 9:07 ` [PATCH 26/28] cpuset: use static key better and convert to new API Mel Gorman
2016-04-26 19:49 ` Vlastimil Babka
2016-04-15 9:07 ` [PATCH 27/28] mm, page_alloc: Defer debugging checks of freed pages until a PCP drain Mel Gorman
2016-04-27 11:59 ` Vlastimil Babka
2016-04-27 12:01 ` [PATCH 1/3] mm, page_alloc: un-inline the bad part of free_pages_check Vlastimil Babka
2016-04-27 12:01 ` [PATCH 2/3] mm, page_alloc: pull out side effects from free_pages_check Vlastimil Babka
2016-04-27 12:41 ` Mel Gorman
2016-04-27 13:00 ` Vlastimil Babka
2016-04-27 12:01 ` [PATCH 3/3] mm, page_alloc: don't duplicate code in free_pcp_prepare Vlastimil Babka
2016-04-27 12:37 ` [PATCH 1/3] mm, page_alloc: un-inline the bad part of free_pages_check Mel Gorman
2016-04-27 12:53 ` Vlastimil Babka
2016-04-15 9:07 ` [PATCH 28/28] mm, page_alloc: Defer debugging checks of pages allocated from the PCP Mel Gorman
2016-04-27 14:06 ` Vlastimil Babka
2016-04-27 15:31 ` Mel Gorman
2016-05-17 6:41 ` Naoya Horiguchi
2016-05-18 7:51 ` Vlastimil Babka
2016-05-18 7:55 ` Vlastimil Babka
2016-05-18 8:49 ` Mel Gorman
2016-04-26 12:04 ` [PATCH 13/28] mm, page_alloc: Remove redundant check for empty zonelist Vlastimil Babka
2016-04-26 13:00 ` Mel Gorman
2016-04-26 19:11 ` Andrew Morton
2016-04-15 12:44 ` Jesper Dangaard Brouer [this message]
2016-04-15 13:08 ` [PATCH 00/28] Optimise page alloc/free fast paths v3 Mel Gorman
2016-04-16 7:21 ` [PATCH 12/28] mm, page_alloc: Remove unnecessary initialisation from __alloc_pages_nodemask() Mel Gorman
2016-04-26 11:41 ` Vlastimil Babka
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160415144402.5fbe7a1e@redhat.com \
--to=brouer@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@techsingularity.net \
--cc=netdev@vger.kernel.org \
--cc=vbabka@suse.cz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).