mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Tejun Heo <tj@kernel.org>
To: Pin-yen Lin <treapking@chromium.org>
Cc: Brian Norris <briannorris@chromium.org>,
	jiangshanlai@gmail.com, torvalds@linux-foundation.org,
	peterz@infradead.org, linux-kernel@vger.kernel.org,
	kernel-team@meta.com, joshdon@google.com, brho@google.com,
	nhuck@google.com, agk@redhat.com, snitzer@kernel.org,
	void@manifault.com
Subject: Re: [PATCHSET v1 wq/for-6.5] workqueue: Improve unbound workqueue execution locality
Date: Wed, 21 Jun 2023 09:16:35 -1000	[thread overview]
Message-ID: <ZJNMk9oSp1_IYXLU@slm.duckdns.org> (raw)
In-Reply-To: <CAEXTbpconFReyAKxerNCQW5e51CMG=_RU9JHAquyEfSH1aqajA@mail.gmail.com>

Hello, Pin-yen.

On Tue, Jun 13, 2023 at 05:26:48PM +0800, Pin-yen Lin wrote:
...
> >  1. affinity_scope = cache, affinity_strict = 1
> >
> >  2. affinity_scope = cpu, affinity_strict = 0
> >
> >  3. affinity_scope = cpu, affinity_strict = 1
> 
> I pulled down v2 series and tried these settings on our 5.15 kernel.
> Unfortunately none of them showed significant improvement on the
> throughput. It's hard to tell which one is the best because of the
> noise, but the throughput is still all far from our 4.19 kernel or
> simply pinning everything to a single core.
> 
> All the 4 settings (3 settings listed above plus the default) yields
> results between 90 to 120 Mbps, while pinning tasks to a single core
> consistently reaches >250 Mbps.

I find that perplexing given that switching to a per-cpu workqueue remedies
the situation quite a bit, which is how this patchset came to be. #3 is the
same as per-cpu workqueue, so if you're seeing noticeably different
performance numbers between #3 and per-cpu workqueue, there's something
wrong with either the code or test setup.

Also, if you have to ping to a single or some subset of CPUs, you can just
set WQ_SYSFS for the workqueue and set affinities in its sysfs interface
instead of hard-coding the workaround for a specific hardware.

Thanks.

-- 
tejun

  reply	other threads:[~2023-06-21 19:17 UTC|newest]

Thread overview: 73+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-19  0:16 Tejun Heo
2023-05-19  0:16 ` [PATCH 01/24] workqueue: Drop the special locking rule for worker->flags and worker_pool->flags Tejun Heo
2023-05-19  0:16 ` [PATCH 02/24] workqueue: Cleanups around process_scheduled_works() Tejun Heo
2023-05-19  0:16 ` [PATCH 03/24] workqueue: Not all work insertion needs to wake up a worker Tejun Heo
2023-05-23  9:54   ` Lai Jiangshan
2023-05-23 21:37     ` Tejun Heo
2023-08-08  1:15   ` [PATCH v2 " Tejun Heo
2023-05-19  0:16 ` [PATCH 04/24] workqueue: Rename wq->cpu_pwqs to wq->cpu_pwq Tejun Heo
2023-05-19  0:16 ` [PATCH 05/24] workqueue: Relocate worker and work management functions Tejun Heo
2023-05-19  0:16 ` [PATCH 06/24] workqueue: Remove module param disable_numa and sysfs knobs pool_ids and numa Tejun Heo
2023-05-19  0:16 ` [PATCH 07/24] workqueue: Use a kthread_worker to release pool_workqueues Tejun Heo
2023-05-19  0:16 ` [PATCH 08/24] workqueue: Make per-cpu pool_workqueues allocated and released like unbound ones Tejun Heo
2023-05-19  0:16 ` [PATCH 09/24] workqueue: Make unbound workqueues to use per-cpu pool_workqueues Tejun Heo
2023-05-22  6:41   ` Leon Romanovsky
2023-05-22 12:27     ` Dennis Dalessandro
2023-05-19  0:16 ` [PATCH 10/24] workqueue: Rename workqueue_attrs->no_numa to ->ordered Tejun Heo
2023-05-19  0:16 ` [PATCH 11/24] workqueue: Rename NUMA related names to use pod instead Tejun Heo
2023-05-19  0:16 ` [PATCH 12/24] workqueue: Move wq_pod_init() below workqueue_init() Tejun Heo
2023-05-19  0:16 ` [PATCH 13/24] workqueue: Initialize unbound CPU pods later in the boot Tejun Heo
2023-05-19  0:16 ` [PATCH 14/24] workqueue: Generalize unbound CPU pods Tejun Heo
2023-05-30  8:06   ` K Prateek Nayak
2023-06-07  1:50     ` Tejun Heo
2023-05-30 21:18   ` Sandeep Dhavale
2023-05-31 12:14     ` K Prateek Nayak
2023-06-07 22:13       ` Tejun Heo
2023-06-08  3:01         ` K Prateek Nayak
2023-06-08 22:50           ` Tejun Heo
2023-06-09  3:43             ` K Prateek Nayak
2023-06-14 18:49               ` Sandeep Dhavale
2023-06-21 20:14                 ` Tejun Heo
2023-06-19  4:30             ` Swapnil Sapkal
2023-06-21 20:38               ` Tejun Heo
2023-07-05  7:04             ` K Prateek Nayak
2023-07-05 18:39               ` Tejun Heo
2023-07-11  3:02                 ` K Prateek Nayak
2023-07-31 23:52                   ` Tejun Heo
2023-08-08  1:08                     ` Tejun Heo
2023-05-19  0:17 ` [PATCH 15/24] workqueue: Add tools/workqueue/wq_dump.py which prints out workqueue configuration Tejun Heo
2023-05-19  0:17 ` [PATCH 16/24] workqueue: Modularize wq_pod_type initialization Tejun Heo
2023-05-19  0:17 ` [PATCH 17/24] workqueue: Add multiple affinity scopes and interface to select them Tejun Heo
2023-05-19  0:17 ` [PATCH 18/24] workqueue: Factor out work to worker assignment and collision handling Tejun Heo
2023-05-19  0:17 ` [PATCH 19/24] workqueue: Factor out need_more_worker() check and worker wake-up Tejun Heo
2023-05-19  0:17 ` [PATCH 20/24] workqueue: Add workqueue_attrs->__pod_cpumask Tejun Heo
2023-05-19  0:17 ` [PATCH 21/24] workqueue: Implement non-strict affinity scope for unbound workqueues Tejun Heo
2023-05-19  0:17 ` [PATCH 22/24] workqueue: Add "Affinity Scopes and Performance" section to documentation Tejun Heo
2023-05-19  0:17 ` [PATCH 23/24] workqueue: Add pool_workqueue->cpu Tejun Heo
2023-05-19  0:17 ` [PATCH 24/24] workqueue: Implement localize-to-issuing-CPU for unbound workqueues Tejun Heo
2023-05-19  0:41 ` [PATCHSET v1 wq/for-6.5] workqueue: Improve unbound workqueue execution locality Linus Torvalds
2023-05-19 22:35   ` Tejun Heo
2023-05-19 23:03     ` Tejun Heo
2023-05-23  1:51       ` Linus Torvalds
2023-05-23 17:59         ` Linus Torvalds
2023-05-23 20:08           ` Rik van Riel
2023-05-23 21:36           ` Sandeep Dhavale
2023-05-23 11:18 ` Peter Zijlstra
2023-05-23 16:12   ` Vincent Guittot
2023-05-24  7:34     ` Peter Zijlstra
2023-05-24 13:15       ` Vincent Guittot
2023-06-05  4:46     ` Gautham R. Shenoy
2023-06-07 14:42       ` Libo Chen
2023-05-26  1:12   ` Tejun Heo
2023-05-30 11:32     ` Peter Zijlstra
2023-06-12 23:56 ` Brian Norris
2023-06-13  2:48   ` Tejun Heo
2023-06-13  9:26     ` Pin-yen Lin
2023-06-21 19:16       ` Tejun Heo [this message]
2023-06-21 19:31         ` Linus Torvalds
2023-06-29  9:49           ` Pin-yen Lin
2023-07-03 21:47             ` Tejun Heo
2023-08-08  1:22 ` Tejun Heo
2023-08-08  2:58   ` K Prateek Nayak
2023-08-08  7:59     ` Tejun Heo
2023-08-18  4:05     ` K Prateek Nayak

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=ZJNMk9oSp1_IYXLU@slm.duckdns.org \
    --to=tj@kernel.org \
    --cc=agk@redhat.com \
    --cc=brho@google.com \
    --cc=briannorris@chromium.org \
    --cc=jiangshanlai@gmail.com \
    --cc=joshdon@google.com \
    --cc=kernel-team@meta.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nhuck@google.com \
    --cc=peterz@infradead.org \
    --cc=snitzer@kernel.org \
    --cc=torvalds@linux-foundation.org \
    --cc=treapking@chromium.org \
    --cc=void@manifault.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
all inboxes | Powered by JetHome®