From: Tejun Heo <tj@kernel.org>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
Linux Kernel <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
Hillf Danton <hillf.zj@alibaba-inc.com>,
Jesper Dangaard Brouer <brouer@redhat.com>,
Petr Mladek <pmladek@suse.cz>
Subject: Re: [PATCH 3/4] mm, page_alloc: Drain per-cpu pages from workqueue context
Date: Mon, 23 Jan 2017 15:55:01 -0500 [thread overview]
Message-ID: <20170123205501.GA25944@htj.duckdns.org> (raw)
In-Reply-To: <20170123200412.mkesardc4mckk6df@techsingularity.net>
Hello, Mel.
On Mon, Jan 23, 2017 at 08:04:12PM +0000, Mel Gorman wrote:
> What is the actual mechanism that does that? It's not something that
> schedule_on_each_cpu does and one would expect that the core workqueue
> implementation would get this sort of detail correct. Or is this a proposal
> on how it should be done?
If you use schedule_on_each_cpu(), it's all fine as the thing pins
cpus and waits for all the work items synchronously. If you wanna do
it asynchronously, right now, you'll have to manually synchronize work
items against the offline callback manually.
On this area, the current workqueue behavior is pretty bad.
Historically, we didn't distinguish affinity-for-optimization
affinity-for-correctness, so we couldn't really enforce strong
behaviors on it. We started distinguishing them some releases ago, so
I should revisit it soon.
Thanks.
--
tejun
--
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:[~2017-01-23 20:55 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-17 9:29 [PATCH 0/4] Use per-cpu allocator for !irq requests and prepare for a bulk allocator v4 Mel Gorman
2017-01-17 9:29 ` [PATCH 1/4] mm, page_alloc: Split buffered_rmqueue Mel Gorman
2017-01-17 18:07 ` Jesper Dangaard Brouer
2017-01-17 18:17 ` Vlastimil Babka
2017-01-17 20:20 ` Mel Gorman
2017-01-17 21:07 ` Mel Gorman
2017-01-17 21:24 ` Vlastimil Babka
2017-01-17 9:29 ` [PATCH 2/4] mm, page_alloc: Split alloc_pages_nodemask Mel Gorman
2017-01-17 9:29 ` [PATCH 3/4] mm, page_alloc: Drain per-cpu pages from workqueue context Mel Gorman
2017-01-20 14:26 ` Vlastimil Babka
2017-01-20 15:26 ` Mel Gorman
2017-01-23 16:29 ` Petr Mladek
2017-01-23 16:50 ` Mel Gorman
2017-01-23 17:03 ` Tejun Heo
2017-01-23 20:04 ` Mel Gorman
2017-01-23 20:55 ` Tejun Heo [this message]
2017-01-23 23:04 ` Mel Gorman
2017-01-24 16:07 ` Tejun Heo
2017-01-24 23:54 ` Mel Gorman
2017-01-25 2:02 ` Tejun Heo
2017-01-25 8:30 ` Mel Gorman
2017-01-24 11:08 ` Vlastimil Babka
2017-01-17 9:29 ` [PATCH 4/4] mm, page_alloc: Only use per-cpu allocator for irq-safe requests Mel Gorman
2017-01-20 15:02 ` Vlastimil Babka
2017-01-23 11:17 ` Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2017-01-23 15:39 [PATCH 0/4] Use per-cpu allocator for !irq requests and prepare for a bulk allocator v5 Mel Gorman
2017-01-23 15:39 ` [PATCH 3/4] mm, page_alloc: Drain per-cpu pages from workqueue context Mel Gorman
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=20170123205501.GA25944@htj.duckdns.org \
--to=tj@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=brouer@redhat.com \
--cc=hillf.zj@alibaba-inc.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@techsingularity.net \
--cc=pmladek@suse.cz \
--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).