From: Josh Triplett <josh@joshtriplett.org>
To: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Herbert Xu <herbert@gondor.apana.org.au>,
Steffen Klassert <steffen.klassert@secunet.com>,
Alex Williamson <alex.williamson@redhat.com>,
Alexander Duyck <alexander.h.duyck@linux.intel.com>,
Dan Williams <dan.j.williams@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
David Hildenbrand <david@redhat.com>,
Jason Gunthorpe <jgg@ziepe.ca>, Jonathan Corbet <corbet@lwn.net>,
Kirill Tkhai <ktkhai@virtuozzo.com>,
Michal Hocko <mhocko@kernel.org>, Pavel Machek <pavel@ucw.cz>,
Pavel Tatashin <pasha.tatashin@soleen.com>,
Peter Zijlstra <peterz@infradead.org>,
Randy Dunlap <rdunlap@infradead.org>,
Shile Zhang <shile.zhang@linux.alibaba.com>,
Tejun Heo <tj@kernel.org>, Zi Yan <ziy@nvidia.com>,
linux-crypto@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/7] padata: parallelize deferred page init
Date: Thu, 30 Apr 2020 18:09:35 -0700 [thread overview]
Message-ID: <20200501010935.GB104377@localhost> (raw)
In-Reply-To: <20200430201125.532129-1-daniel.m.jordan@oracle.com>
On Thu, Apr 30, 2020 at 04:11:18PM -0400, Daniel Jordan wrote:
> Sometimes the kernel doesn't take full advantage of system memory
> bandwidth, leading to a single CPU spending excessive time in
> initialization paths where the data scales with memory size.
>
> Multithreading naturally addresses this problem, and this series is the
> first step.
>
> It extends padata, a framework that handles many parallel singlethreaded
> jobs, to handle multithreaded jobs as well by adding support for
> splitting up the work evenly, specifying a minimum amount of work that's
> appropriate for one helper thread to do, load balancing between helpers,
> and coordinating them. More documentation in patches 4 and 7.
>
> The first user is deferred struct page init, a large bottleneck in
> kernel boot--actually the largest for us and likely others too. This
> path doesn't require concurrency limits, resource control, or priority
> adjustments like future users will (vfio, hugetlb fallocate, munmap)
> because it happens during boot when the system is otherwise idle and
> waiting on page init to finish.
>
> This has been tested on a variety of x86 systems and speeds up kernel
> boot by 6% to 49% by making deferred init 63% to 91% faster. Patch 6
> has detailed numbers. Test results from other systems appreciated.
>
> This series is based on v5.6 plus these three from mmotm:
>
> mm-call-touch_nmi_watchdog-on-max-order-boundaries-in-deferred-init.patch
> mm-initialize-deferred-pages-with-interrupts-enabled.patch
> mm-call-cond_resched-from-deferred_init_memmap.patch
>
> All of the above can be found in this branch:
>
> git://oss.oracle.com/git/linux-dmjordan.git padata-mt-definit-v1
> https://oss.oracle.com/git/gitweb.cgi?p=linux-dmjordan.git;a=shortlog;h=refs/heads/padata-mt-definit-v1
For the series (and the three prerequisite patches):
Tested-by: Josh Triplett <josh@joshtriplett.org>
Thank you for writing this, and thank you for working towards
upstreaming it!
next prev parent reply other threads:[~2020-05-01 1:09 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-30 20:11 [PATCH 0/7] padata: parallelize deferred page init Daniel Jordan
2020-04-30 20:11 ` [PATCH 1/7] padata: remove exit routine Daniel Jordan
2020-04-30 20:11 ` [PATCH 2/7] padata: initialize earlier Daniel Jordan
2020-04-30 20:11 ` [PATCH 3/7] padata: allocate work structures for parallel jobs from a pool Daniel Jordan
2020-04-30 20:11 ` [PATCH 4/7] padata: add basic support for multithreaded jobs Daniel Jordan
2020-04-30 20:11 ` [PATCH 5/7] mm: move zone iterator outside of deferred_init_maxorder() Daniel Jordan
2020-04-30 21:43 ` Alexander Duyck
2020-05-01 2:45 ` Daniel Jordan
2020-05-04 22:10 ` Alexander Duyck
2020-05-05 0:54 ` Daniel Jordan
2020-05-05 15:27 ` Alexander Duyck
2020-05-06 22:39 ` Daniel Jordan
2020-05-07 15:26 ` Alexander Duyck
2020-05-07 20:20 ` Daniel Jordan
2020-05-07 21:18 ` Alexander Duyck
2020-05-07 22:15 ` Daniel Jordan
2020-04-30 20:11 ` [PATCH 6/7] mm: parallelize deferred_init_memmap() Daniel Jordan
2020-05-04 22:33 ` Alexander Duyck
2020-05-04 23:38 ` Josh Triplett
2020-05-05 0:40 ` Alexander Duyck
2020-05-05 1:48 ` Daniel Jordan
2020-05-05 2:09 ` Daniel Jordan
2020-05-05 14:55 ` Alexander Duyck
2020-05-06 22:21 ` Daniel Jordan
2020-05-06 22:36 ` Alexander Duyck
2020-05-06 22:43 ` Daniel Jordan
2020-05-06 23:01 ` Daniel Jordan
2020-05-05 1:26 ` Daniel Jordan
2020-04-30 20:11 ` [PATCH 7/7] padata: document multithreaded jobs Daniel Jordan
2020-04-30 21:31 ` [PATCH 0/7] padata: parallelize deferred page init Andrew Morton
2020-04-30 21:40 ` Pavel Tatashin
2020-05-01 2:40 ` Daniel Jordan
2020-05-01 0:50 ` Josh Triplett
2020-05-01 1:09 ` Josh Triplett [this message]
2020-05-01 2:48 ` 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=20200501010935.GB104377@localhost \
--to=josh@joshtriplett.org \
--cc=akpm@linux-foundation.org \
--cc=alex.williamson@redhat.com \
--cc=alexander.h.duyck@linux.intel.com \
--cc=corbet@lwn.net \
--cc=dan.j.williams@intel.com \
--cc=daniel.m.jordan@oracle.com \
--cc=dave.hansen@linux.intel.com \
--cc=david@redhat.com \
--cc=herbert@gondor.apana.org.au \
--cc=jgg@ziepe.ca \
--cc=ktkhai@virtuozzo.com \
--cc=linux-crypto@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=pasha.tatashin@soleen.com \
--cc=pavel@ucw.cz \
--cc=peterz@infradead.org \
--cc=rdunlap@infradead.org \
--cc=shile.zhang@linux.alibaba.com \
--cc=steffen.klassert@secunet.com \
--cc=tj@kernel.org \
--cc=ziy@nvidia.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).