From: Aaron Lu <aaron.lu@intel.com>
To: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Vlastimil Babka <vbabka@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
Huang Ying <ying.huang@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Kemi Wang <kemi.wang@intel.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Andi Kleen <ak@linux.intel.com>, Michal Hocko <mhocko@suse.com>,
Mel Gorman <mgorman@techsingularity.net>,
Matthew Wilcox <willy@infradead.org>
Subject: Re: [RFC PATCH v2 0/4] Eliminate zone->lock contention for will-it-scale/page_fault1 and parallel free
Date: Thu, 22 Mar 2018 09:30:49 +0800 [thread overview]
Message-ID: <20180322013049.GA4056@intel.com> (raw)
In-Reply-To: <1dfd4b33-6eff-160e-52fd-994d9bcbffed@oracle.com>
On Wed, Mar 21, 2018 at 01:44:25PM -0400, Daniel Jordan wrote:
> On 03/20/2018 04:54 AM, Aaron Lu wrote:
> ...snip...
> > reduced zone->lock contention on free path from 35% to 1.1%. Also, it
> > shows good result on parallel free(*) workload by reducing zone->lock
> > contention from 90% to almost zero(lru lock increased from almost 0 to
> > 90% though).
>
> Hi Aaron, I'm looking through your series now. Just wanted to mention that I'm seeing the same interaction between zone->lock and lru_lock in my own testing. IOW, it's not enough to fix just one or the other: both need attention to get good performance on a big system, at least in this microbenchmark we've both been using.
Agree.
>
> There's anti-scaling at high core counts where overall system page faults per second actually decrease with more CPUs added to the test. This happens when either zone->lock or lru_lock contention are completely removed, but the anti-scaling goes away when both locks are fixed.
>
> Anyway, I'll post some actual data on this stuff soon.
Looking forward to that, thanks.
In the meantime, I'll also try your lru_lock optimization work on top of
this patchset to see if the lock contention shifts back to zone->lock.
next prev parent reply other threads:[~2018-03-22 1:29 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-20 8:54 [RFC PATCH v2 0/4] Eliminate zone->lock contention for will-it-scale/page_fault1 and parallel free Aaron Lu
2018-03-20 8:54 ` [RFC PATCH v2 1/4] mm/page_alloc: use helper functions to add/remove a page to/from buddy Aaron Lu
2018-03-20 11:35 ` Vlastimil Babka
2018-03-20 13:50 ` Aaron Lu
2018-03-20 8:54 ` [RFC PATCH v2 2/4] mm/__free_one_page: skip merge for order-0 page unless compaction failed Aaron Lu
2018-03-20 11:45 ` Vlastimil Babka
2018-03-20 14:11 ` Aaron Lu
2018-03-21 7:53 ` Vlastimil Babka
2018-03-22 17:15 ` Matthew Wilcox
2018-03-22 18:39 ` Daniel Jordan
2018-03-22 18:50 ` Matthew Wilcox
[not found] ` <CAF7GXvovKsabDw88icK5c5xBqg6g0TomQdspfi4ikjtbg=XzGQ@mail.gmail.com>
2018-03-21 1:59 ` Aaron Lu
[not found] ` <CAF7GXvrQG0+iPu8h13coo2QW7WxNhjHA1JAaOYoEBBB9-obRSQ@mail.gmail.com>
2018-03-21 4:53 ` Aaron Lu
[not found] ` <CAF7GXvpzZassTEebX7nS0u_xynns=mxEF28rPBhXX9Yp4xQ3hw@mail.gmail.com>
2018-03-21 7:42 ` Aaron Lu
2018-03-20 8:54 ` [RFC PATCH v2 3/4] mm/rmqueue_bulk: alloc without touching individual page structure Aaron Lu
[not found] ` <CAF7GXvpzgc0vsJemUYQPhPFte8b8a4nBFo=iwZBTdM1Y2eoHYw@mail.gmail.com>
2018-03-21 1:52 ` Aaron Lu
2018-03-21 12:55 ` Vlastimil Babka
2018-03-21 15:01 ` Aaron Lu
2018-03-29 19:16 ` Daniel Jordan
2018-03-20 8:54 ` [RFC PATCH v2 4/4] mm/free_pcppages_bulk: reduce overhead of cluster operation on free path Aaron Lu
2018-03-21 17:44 ` [RFC PATCH v2 0/4] Eliminate zone->lock contention for will-it-scale/page_fault1 and parallel free Daniel Jordan
2018-03-22 1:30 ` Aaron Lu [this message]
2018-03-22 11:20 ` Daniel Jordan
2018-03-29 19:19 ` Daniel Jordan
2018-03-30 1:42 ` Aaron Lu
2018-03-30 14:27 ` Daniel Jordan
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=20180322013049.GA4056@intel.com \
--to=aaron.lu@intel.com \
--cc=ak@linux.intel.com \
--cc=akpm@linux-foundation.org \
--cc=daniel.m.jordan@oracle.com \
--cc=dave.hansen@linux.intel.com \
--cc=kemi.wang@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@techsingularity.net \
--cc=mhocko@suse.com \
--cc=tim.c.chen@linux.intel.com \
--cc=vbabka@suse.cz \
--cc=willy@infradead.org \
--cc=ying.huang@intel.com \
/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).