Kei386EoiHelper and ExReleaseRundownProtectionCacheAware Perf Profiler

NTDEV
1

Hi,

In order to optimize my driver and user mode component (FS mini filter driver) I used a performance profiler to see what can be optimized.

I am seeing 2 functions on the top of the list with 22% and 21% that I am not sure what are they. Is anyone familiar with them and knows what are they used for?

Thanks,
Vance

22.28% Kei386EoiHelper
21.69% ExReleaseRundownProtectionCacheAware
13.29% IofCallDriver
…

2

I don’t know about the second one, but the first one is invoked upon returning from interrupt. Therefore, whenever the return to the UM is made this function gets invoked. This is why you see that it occupies a significant share of CPU time…

Anton Bassov

3

The 2nd is a cache spanned ref count structure used to track outstanding io. I am pretty sure the fs filter manager uses these.

d

-----Original Message-----
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Sent: Tuesday, December 30, 2008 2:04 PM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] Kei386EoiHelper and ExReleaseRundownProtectionCacheAware Perf Profiler

I don’t know about the second one, but the first one is invoked upon returning from interrupt. Therefore, whenever the return to the UM is made this function gets invoked. This is why you see that it occupies a significant share of CPU time…

Anton Bassov

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