Messages in this thread | | | Date | Tue, 24 Nov 2009 09:17:40 -0600 (CST) | From | Christoph Lameter <> | Subject | Re: [MM] Make mm counters per cpu instead of atomic |
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On Tue, 24 Nov 2009, Zhang, Yanmin wrote:
> > True.... We need to find some alternative to per cpu data to scale mmap > > sem then. > I ran lots of benchmarks such like specjbb2005/hackbench/tbench/dbench/iozone > /sysbench_oltp(mysql)/aim7 against percpu tree(based on 2.6.32-rc7) on a 4*8*2 logical > cpu machine, and didn't find big result difference between with your patch and without > your patch.
This affects loads that heavily use mmap_sem. You wont find too many issues in tests that do not run processes with a large thread count and cause lots of faults or uses of get_user_pages(). The tests you list are not of that nature.
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