From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>,
linux-pm@lists.linux-foundation.org,
linux-kernel@vger.kernel.org,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Subject: Re: [RFC][PATCH] PM: disable nonboot cpus before suspending devices
Date: Wed, 3 Feb 2010 23:34:37 +0100 [thread overview]
Message-ID: <201002032334.37198.rjw@sisk.pl> (raw)
In-Reply-To: <20100202174853.67eeccdd.akpm@linux-foundation.org>
On Wednesday 03 February 2010, Andrew Morton wrote:
> On Wed, 3 Feb 2010 02:44:23 +0100 "Rafael J. Wysocki" <rjw@sisk.pl> wrote:
>
> > +static inline gfp_t clear_gfp_allowed_mask(gfp_t mask)
> > +{
> > + gfp_t ret = gfp_allowed_mask;
> > + gfp_allowed_mask &= ~mask;
> > + return ret;
> > +}
>
> Fair enuf.
>
> Of course, this is all horridly racy/buggy without locking. Would I be
> correct in hoping that all the callers happen when the system is in
> everyone-is-frozen mode?
As far as I can tell, gfp_allowed_mask is only touched during init apart from
this.
> Perhaps we should add some documentation (or even an assertion) to
> prevent someone from using these interfaces from within normal code.
I thought about that, but didn't invent anything smart enough.
Well, maybe except for a comment like "this must be called with pm_mutex held",
because that's the only case when it would be really safe.
Rafael
next prev parent reply other threads:[~2010-02-03 22:34 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-22 18:00 [RFC][PATCH] PM: disable nonboot cpus before suspending devices Sebastian Ott
2010-01-22 20:48 ` Rafael J. Wysocki
2010-01-22 21:24 ` Rafael J. Wysocki
2010-01-25 15:08 ` Sebastian Ott
2010-01-25 21:37 ` Rafael J. Wysocki
2010-02-01 14:41 ` Sebastian Ott
2010-02-01 15:30 ` Rafael J. Wysocki
2010-02-01 15:43 ` Maxim Levitsky
2010-02-01 15:57 ` Andrew Morton
2010-02-03 1:44 ` Rafael J. Wysocki
2010-02-03 1:48 ` Andrew Morton
2010-02-03 22:34 ` Rafael J. Wysocki [this message]
2010-02-03 23:08 ` Andrew Morton
2010-02-04 0:50 ` Rafael J. Wysocki
2010-02-04 1:21 ` Andrew Morton
2010-02-04 1:41 ` Andrew Morton
2010-02-04 19:33 ` Rafael J. Wysocki
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