Re: statistics collector process is thrashing my cpu

On Thu, May 8, 2008 at 6:14 PM, Magnus Hagander <magnus(at)hagander(dot)net> wrote:
> William Temperley wrote:
>> > >
>> > > Any ideas why this might be happening, and how I can stop it?
>> >
>> > It'd be interesting to know what the stats collector is actually
>> > doing. Could you, using Process Explorer or a debugger, get a stack
>> > trace from that process while it's in the trashing state?
>> >
>> > //Magnus
>> >
>>
>> Certainly, but I'll have to wait 'til it does it again, it doesn't
>> happen all the time.
>> What would you like to know from Process Explorer?
>
> Get the backtrace from hung process. Find the process in the list, open
> it. Go to the tab "Threads", find the thread that's using a lot of CPU
> (or at least has a lot of ocntext switchs), and click the Stack button.
> That should give you a window with a backtrace.
>
> //Magnus
>

Ok, got the little blighter. Below are 4 stack traces taken at random times.
Doesn't seem to be doing much I/O (16 reads and 167 other in 3 hours).
The memory usage seems to be static (3.7MB) even with high database
usage (vacuum, read, update).

ntoskrnl.exe+0x584d
ntoskrnl.exe!MmCreateMdl+0x28a
hal.dll+0x2ef2
ntoskrnl.exe!IoCheckFunctionAccess+0x1d8a6
ntoskrnl.exe!RtlFindUnicodePrefix+0x29
ntoskrnl.exe!MmPrefetchPages+0xc59
ntoskrnl.exe!ZwSetSystemInformation+0x23
ntdll.dll!KiFastSystemCallRet
mswsock.dll+0x6e2d
mswsock.dll+0x6039
WS2_32.dll!WSAAddressToStringW+0x1c9
WS2_32.dll!WSAAddressToStringW+0x113
WS2_32.dll!WSAEventSelect+0x2f
postgres.exe!RemoveTSConfiguration+0x151837
postgres.exe!RemoveTSConfiguration+0x15a586

ntoskrnl.exe!ZwAssignProcessToJobObject+0x15
ntoskrnl.exe!MmCreateMdl+0x28a
hal.dll!HalClearSoftwareInterrupt+0x342
hal.dll!HalRequestSoftwareInterrupt+0x3c
ntoskrnl.exe!SeCaptureSecurityDescriptor+0x41e
ntoskrnl.exe!ZwSetSystemInformation+0x23
ntdll.dll!KiFastSystemCallRet
postgres.exe!RemoveTSConfiguration+0x151788
postgres.exe!RemoveTSConfiguration+0x15a586

ntoskrnl.exe!ZwAssignProcessToJobObject+0x15
ntoskrnl.exe!MmCreateMdl+0x28a
hal.dll!HalClearSoftwareInterrupt+0x342
ntoskrnl.exe!IoCheckFunctionAccess+0x1d8a6
ntoskrnl.exe!RtlFindUnicodePrefix+0x29
ntoskrnl.exe!MmPrefetchPages+0xc59
ntoskrnl.exe!ZwSetSystemInformation+0x23
ntdll.dll!KiFastSystemCallRet
mswsock.dll+0x6e2d
mswsock.dll+0x6039
WS2_32.dll!WSAAddressToStringW+0x1c9
WS2_32.dll!WSAAddressToStringW+0x113
WS2_32.dll!WSAEventSelect+0x2f
postgres.exe!RemoveTSConfiguration+0x151837
postgres.exe!RemoveTSConfiguration+0x15a586

ntoskrnl.exe!ZwAssignProcessToJobObject+0x15
ntoskrnl.exe!MmCreateMdl+0x28a
hal.dll!HalClearSoftwareInterrupt+0x342
mswsock.dll+0x5f38
mswsock.dll+0x6e75
mswsock.dll+0x6e2d
mswsock.dll+0x6039
WS2_32.dll!WSAAddressToStringW+0x1c9
WS2_32.dll!WSAAddressToStringW+0x113
WS2_32.dll!WSAEventSelect+0x2f
postgres.exe!RemoveTSConfiguration+0x151837
postgres.exe!RemoveTSConfiguration+0x15a586

Hope that means more to you than me,

Will