From: Arnd Bergmann <arnd@arndb.de>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
"linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
Ulf Hansson <ulf.hansson@linaro.org>,
Chunyan Zhang <zhang.chunyan@linaro.org>,
Baolin Wang <baolin.wang@linaro.org>,
Linux PM <linux-pm@vger.kernel.org>,
"Rafael J . Wysocki" <rjw@rjwysocki.net>,
Russell King <linux@armlinux.org.uk>,
Jiri Kosina <jikos@kernel.org>
Subject: Re: [PATCH] RFC: mmc: block: replace semaphore with freezing
Date: Wed, 16 Nov 2016 17:32:44 +0100 [thread overview]
Message-ID: <17679227.zg8zl3jhbr@wuerfel> (raw)
In-Reply-To: <CACRpkdY+jdU4ETuMJsY-efSkjwE0fWWRZoyCyrYAs_GxUo-DhQ@mail.gmail.com>
On Wednesday, November 16, 2016 4:20:47 PM CET Linus Walleij wrote:
> On Wed, Nov 16, 2016 at 1:46 PM, Rafael J. Wysocki <rafael@kernel.org> wrote:
>
> > Well, we had a session at the KS regarding usage of the freezer on
> > kernel threads and the conclusion was to get rid of that (as opposed
> > to freezing user space, which is necessary IMO). So this change would
> > go in the opposite direction.
>
> Aha so I should not make this thread look like everyone else, instead
> everyone else should look like this thread, haha
>
> Ah well, I'll just drop it.
It would still be good to remove the semaphore and do something else,
as we also want to remove all semaphores. ;-)
We could check "mq->flags & MMC_QUEUE_SUSPENDED" in the kthread to see
if the queue is currently suspended, and otherwise go to sleep there,
and then call wake_up() in the resume function.
While looking at that code, I just noticed that access to
mq->flags is racy and should be fixed as well.
Arnd
next prev parent reply other threads:[~2016-11-16 16:33 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-16 10:51 [PATCH] RFC: mmc: block: replace semaphore with freezing Linus Walleij
2016-11-16 12:19 ` Arnd Bergmann
2016-11-16 12:46 ` Rafael J. Wysocki
2016-11-16 12:57 ` Jiri Kosina
2016-11-16 15:20 ` Linus Walleij
2016-11-16 16:32 ` Arnd Bergmann [this message]
2016-11-22 8:54 ` Linus Walleij
2016-11-22 9:10 ` Russell King - ARM Linux
2016-11-22 9:16 ` Arnd Bergmann
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=17679227.zg8zl3jhbr@wuerfel \
--to=arnd@arndb.de \
--cc=baolin.wang@linaro.org \
--cc=jikos@kernel.org \
--cc=linus.walleij@linaro.org \
--cc=linux-mmc@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=rafael@kernel.org \
--cc=rjw@rjwysocki.net \
--cc=ulf.hansson@linaro.org \
--cc=zhang.chunyan@linaro.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