Messages in this thread | | | Subject | Re: Mainline kernel OLTP performance update | From | Andi Kleen <> | Date | Wed, 29 Apr 2009 10:28:25 +0200 |
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Andrew Morton <akpm@linux-foundation.org> writes:
>> ======oprofile CPU_CLK_UNHALTED for top 30 functions >> Cycles% 2.6.24.2 Cycles% 2.6.30-rc3 >> 74.8578 <database> 69.1925 <database> > > ouch, that's a large drop in userspace CPU occupancy. It seems > inconsistent with the 1.91% above.
That was determined to be an oprofile artifact/regression (see Doug's other email+thread) The 2.6.30 oprofile seems to be less accurate than the one in 2.6.24. Of course the question is if it can't get the user space right, is the kernel data accurate. But I believe Doug verified with vtune that the kernel data is roughly correct, just user space profiling was slightly bogus (right, Doug, or do I misrepresent that?)
-Andi
-- ak@linux.intel.com -- Speaking for myself only.
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