Messages in this thread | | | Date | Mon, 5 Apr 2010 20:30:06 +0300 | Subject | Re: hackbench regression due to commit 9dfc6e68bfe6e | From | Pekka Enberg <> |
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(I'm CC'ing Tejun)
On Mon, Apr 5, 2010 at 4:54 PM, Christoph Lameter <cl@linux-foundation.org> wrote: > On Fri, 2 Apr 2010, Zhang, Yanmin wrote: > >> My testing command on my 2 socket machine: >> #hackbench 100 process 20000 >> >> With 2.6.33, it takes for about 96 seconds while 2.6.34-rc2 (or the latest tip tree) >> takes for about 101 seconds. >> >> perf shows some functions around SLUB have more cpu utilization, while some other >> SLUB functions have less cpu utilization. > > Hmnmmm... The dynamic percpu areas use page tables and that data is used > in the fast path. Maybe the high thread count causes tlb trashing?
Hmm indeed. I don't see anything particularly funny in the SLUB percpu conversion so maybe this is a more issue with the new percpu allocator?
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