Messages in this thread | | | Subject | Re: [RFC 4/4]x86: avoid tlbstate lock if no enough cpus | From | Eric Dumazet <> | Date | Thu, 04 Nov 2010 06:42:46 +0100 |
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Le jeudi 04 novembre 2010 à 13:21 +0800, Shaohua Li a écrit : > On Wed, 2010-11-03 at 17:08 +0800, Eric Dumazet wrote: > > Le mercredi 03 novembre 2010 à 16:41 +0800, Shaohua Li a écrit : > > > > > yes, this is ok. we might need avoid some cpu hotplug race too. I'll > > > post a new patch later. > > > > > > > > > > Hmm, maybe only set the variable "must take the lock", never unset it. > I followed your suggestions to use nr_cpu_ids, it should be good enough. >
Yes, unfortunately not on HP machines, because of their tendency to have holes in CPU numberings :)
This can probably can improved later.
Thanks
> Thanks, > Shaohua > > > This one isn't related to previous patch. If online cpus are below > NUM_INVALIDATE_TLB_VECTORS, we don't need the lock. The comments > in the code declares we don't need the check, but a hot lock still > needs an atomic operation and expensive, so add the check here. > > Uses nr_cpu_ids here as suggested by Eric Dumazet. > > Signed-off-by: Shaohua Li <shaohua.li@intel.com> > ---
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
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