Messages in this thread | | | Date | Mon, 07 Nov 2005 12:06:20 +1100 | From | Nick Piggin <> | Subject | Re: [patch 1/14] mm: opt rmqueue |
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Andi Kleen wrote: > Nick Piggin <nickpiggin@yahoo.com.au> writes: > > >>1/14 >> >>-- >>SUSE Labs, Novell Inc. >> >>Slightly optimise some page allocation and freeing functions by >>taking advantage of knowing whether or not interrupts are disabled. > > > Another thing that could optimize that would be to use local_t > for the per zone statistics and the VM statistics (i have an > old patch for the later, needs polishing up for the current > kernel) > With an architecture optimized for it (like i386/x86-64) they > generate much better code. >
Yes, all this turning on and off of interrupts does have a significant cost here.
With the full patchset applied, most of the hot path statistics get put under areas that already require interrupts to be off, however there are still a few I didn't get around to doing. zone_statistics on CONFIG_NUMA, for example.
I wonder if local_t is still good on architectures like ppc64 where it still requires an ll/sc sequence?
Nick
-- SUSE Labs, Novell Inc.
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