From: tixy@linaro.org (Jon Medhurst (Tixy))
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: make cpu_init() notrace
Date: Mon, 22 Apr 2013 19:08:36 +0100 [thread overview]
Message-ID: <1366654116.3989.16.camel@computer5.home> (raw)
In-Reply-To: <20130422140711.GI14496@n2100.arm.linux.org.uk>
On Mon, 2013-04-22 at 15:07 +0100, Russell King - ARM Linux wrote:
> On Thu, Apr 18, 2013 at 05:20:46PM +0100, Jon Medhurst (Tixy) wrote:
> > On resume from CPU power down any trace hooks enabled in cpu_init()
> > will get called before that function has done set_my_cpu_offset(),
> > so any use of per-cpu variables by trace hook code will cause bad
> > things to happen. Prevent this by marking the function notrace.
> >
> > This fixes lockups/crashes seen when enabling function tracer on TC2
> > with the not yet mainlined cpuidle driver.
>
> Looks sane. Needs to go to the patch system though. Not sure if it'll
> make 3.9 given its proximity (we're on -rc8).
Added as patch 7700/1. Don't think there is a big rush as the problem
has probably been there since 3.8 when commit 14318efb (implement
optimized percpu variable access) started using TPIDRPRW; which is
presumably lost over CPU power down.
--
Tixy
next prev parent reply other threads:[~2013-04-22 18:08 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-18 16:20 [PATCH] ARM: make cpu_init() notrace Jon Medhurst (Tixy)
2013-04-19 21:37 ` Nicolas Pitre
2013-04-22 14:07 ` Russell King - ARM Linux
2013-04-22 18:08 ` Jon Medhurst (Tixy) [this message]
2013-04-25 12:15 ` Russell King - ARM Linux
2013-04-25 13:50 ` Jon Medhurst (Tixy)
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=1366654116.3989.16.camel@computer5.home \
--to=tixy@linaro.org \
--cc=linux-arm-kernel@lists.infradead.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).