From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Michael Bringmann <mwb@linux.vnet.ibm.com>
Subject: Re: [GIT PULL] workqueue fixes for v4.13-rc3
Date: Mon, 7 Aug 2017 14:18:51 +0200 [thread overview]
Message-ID: <CAMuHMdUOoKAB9RXWF3gkEf6m0ww1XrYWL6QGzV6ucLQuOX3rUg@mail.gmail.com> (raw)
In-Reply-To: <20170731153806.GC447614@devbig577.frc2.facebook.com>
Hi Tejun,
On Mon, Jul 31, 2017 at 5:38 PM, Tejun Heo <tj@kernel.org> wrote:
> Two notable fixes.
> * Workqueue assumes that CPU <-> NUMA node mapping remains static.
> This is a general assumption - we don't have any synchronization
> mechanism around CPU <-> node mapping. Unfortunately, powerpc may
> change the mapping dynamically leading to crashes. Michael added a
> workaround so that we at least don't crash while powerpc hotplug
> code gets updated.
> Michael Bringmann (1):
> workqueue: Work around edge cases for calc of pool's cpumask
> --- a/kernel/workqueue.c
> +++ b/kernel/workqueue.c
> @@ -3577,6 +3577,13 @@ static bool wq_calc_node_cpumask(const struct workqueue_attrs *attrs, int node,
>
> /* yeap, return possible CPUs in @node that @attrs wants */
> cpumask_and(cpumask, attrs->cpumask, wq_numa_possible_cpumask[node]);
> +
> + if (cpumask_empty(cpumask)) {
> + pr_warn_once("WARNING: workqueue cpumask: online intersect > "
> + "possible intersect\n");
> + return false;
> + }
> +
This triggers on m68k, which doesn't have SMP.
Haven't tried it yet on any other system due to holidays.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
next prev parent reply other threads:[~2017-08-07 12:18 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-31 15:38 [GIT PULL] workqueue fixes for v4.13-rc3 Tejun Heo
2017-08-07 12:18 ` Geert Uytterhoeven [this message]
2017-08-07 17:06 ` Tejun Heo
2017-08-23 8:10 ` Geert Uytterhoeven
2017-08-23 14:24 ` Tejun Heo
2017-08-23 14:47 ` Geert Uytterhoeven
2017-08-23 17:08 ` Tejun Heo
2017-08-24 13:32 ` Geert Uytterhoeven
2017-08-24 14:33 ` Tejun Heo
2017-08-28 9:07 ` Geert Uytterhoeven
2017-08-28 21:52 ` Tejun Heo
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=CAMuHMdUOoKAB9RXWF3gkEf6m0ww1XrYWL6QGzV6ucLQuOX3rUg@mail.gmail.com \
--to=geert@linux-m68k.org \
--cc=jiangshanlai@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mwb@linux.vnet.ibm.com \
--cc=tj@kernel.org \
--cc=torvalds@linux-foundation.org \
/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).