Re: [PATCH] ida: make ida_simple_get/put() IRQ safe

From: Andrew Morton
Date: Fri Oct 28 2011 - 19:20:57 EST


On Fri, 28 Oct 2011 16:11:49 -0700
Tejun Heo <tj@xxxxxxxxxx> wrote:

> On Fri, Oct 28, 2011 at 04:01:15PM -0700, Andrew Morton wrote:
> > On Wed, 26 Oct 2011 13:33:11 -0700
> > Tejun Heo <tj@xxxxxxxxxx> wrote:
> >
> > > It's often convenient to be able to release resource from IRQ context.
> > > Make ida_simple_*() use irqsave/restore spin ops so that they are IRQ
> > > safe.
> >
> > The patch also accidentally makes ida_simple_get() callable from
> > interrupt context. That's a somewhat unreliable operation due to
> > -ENOMEM possibilities even with GFP_ATOMIC.
>
> Hmmm... We can add a WARN_ON_ONCE() there but do we really care? If
> the caller is using GFP_ATOMIC, it should be expecting unreliability.
>

No, I don't think we care - I was just chin-scratching and augmenting
some deficient changeloggery. Also, showing that I'd actually read the
thing ;)


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