Messages in this thread | | | Date | Thu, 4 Sep 2008 09:22:52 +0200 | From | Sebastien Dugue <> | Subject | Re: [PATCH 2/2] powerpc - Make the irq reverse mapping radix tree lockless |
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On Thu, 04 Sep 2008 12:52:19 +1000 Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
> On Wed, 2008-09-03 at 15:41 +0200, Sebastien Dugue wrote: > > On Wed, 20 Aug 2008 15:23:01 +1000 Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote: > > > > > BTW. It would be good to try to turn the GFP_ATOMIC into GFP_KERNEL, > > > > That would be nice indeed > > > > > maybe using a semaphore instead of a lock to protect insertion vs. > > > initialisation. > > > > a semaphore? are you meaning a mutex? If not, I fail to understand what you're > > implying. > > Right, a mutex, bad habit calling those semaphores from the old days :-)
OK, then we're on the same line ;-)
> > > Right, that's the problem with this new scheme and I'm still trying > > to find a way to handle memory allocation failures be it for GFP_ATOMIC or > > GFP_KERNEL. > > > > I could not think of anything simple so far and I'm open for suggestions. > > GFP_KERNEL should not fail, it will just block no ?
No it won't block and will fail (returns NULL).
> If it fails, it's > probably catastrophic enough not to care.
Yep, I'd tend to agree with that.
> You can always fallback to linear lookup.
I will have to add that back as there is no more fallback.
> I don't know if it's worth trying to fire off a new > allocation attempt later, probably not.
I've been pondering with this lately, but I think that adding a linear lookup fallback should be OK.
Thanks,
Sebastien.
> > Ben. > > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-dev >
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