Re: Getting Peak Commit from NtQuerySystemInformation

Mike Driscoll schrieb:
> Hi,
> 
> I was tasked with finding a way to query our workstations for their Peak 
> Commit Charge. According to the sysinternals forum:
> 
> "The only way I'm aware of that one can get this detail is from the 
> uMmPeakCommitLimit member of the SYSTEM_PERFORMANCE_INFORMATION 
> structure one passes to NtQuerySystemInformation when calling it with 
> the SystemPerformanceInformation type." (see 
> http://forum.sysinternals.com/forum_posts.asp?TID=15540&PID=75852)
> 
> I started with this question on the PyWin32 mailing list, but it turns 
> out that they don't expose the functionality inside 
> NtQuerySystemInformation so that's why I came here. Unfortunately, I'm a 
> complete newb when it comes to ctypes. While I did find that this worked 
> "ctypes.windll.ntdll.NtQuerySystemInformation", I don't know how to go 
> on and actually query the object. Can someone give me a clue?
> 
> I'm running Python 2.5 on Windows XP. Thanks!

Not really tested, but seems to work:

<snip>
from ctypes import *

SystemBasicInformation = 0
SystemPerformanceInformation = 2

class SYSTEM_BASIC_INFORMATION(Structure):
    _fields_ = [("Reserved1", c_long * 10),
                ("NumberOfProcessors", c_byte),
                ("bUnknown2", c_byte),
                ("bUnknown3", c_short)
                ]

class SYSTEM_PERFORMANCE_INFORMATION(Structure):
    _fields_ = [("IdleTime", c_int64),
                ("ReadTransferCount", c_int64),
                ("WriteTransferCount", c_int64),
                ("OtherTransferCount", c_int64),
                ("ReadOperationCount", c_ulong),
                ("WriteOperationCount", c_ulong),
                ("OtherOperationCount", c_ulong),
                ("AvailablePages", c_ulong),
                ("TotalCommittedPages", c_ulong),
                ("TotalCommitLimit", c_ulong),
                ("PeakCommitment", c_ulong),
                ("PageFaults", c_ulong),
                ("WriteCopyFaults", c_ulong),
                ("TransitionFaults", c_ulong),
                ("Reserved1", c_ulong),
                ("DemandZeroFaults", c_ulong),
                ("PagesRead", c_ulong),
                ("PageReadIos", c_ulong),
                ("Reserved2", c_ulong * 2),
                ("PagefilePagesWritten", c_ulong),
                ("PagefilePageWriteIos", c_ulong),
                ("MappedFilePagesWritten", c_ulong),
                ("MappedFilePageWriteIos", c_ulong),
                ("PagedPoolUsage", c_ulong),
                ("NonPagedPoolUsage", c_ulong),
                ("PagedPoolAllocs", c_ulong),
                ("PagedPoolFrees", c_ulong),
                ("NonPagedPoolAllocs", c_ulong),
                ("NonPagedPoolFrees", c_ulong),
                ("TotalFreeSystemPtes", c_ulong),
                ("SystemCodePage", c_ulong),
                ("TotalSystemDriverPages", c_ulong),
                ("TotalSystemCodePages", c_ulong),
                ("SmallNonPagedLookasideListAllocateHits", c_ulong),
                ("SmallPagedLookasideListAllocateHits", c_ulong),
                ("Reserved3", c_ulong),
                ("MmSystemCachePage", c_ulong),
                ("PagedPoolPage", c_ulong),
                ("SystemDriverPage", c_ulong),
                ("FastReadNoWait", c_ulong),
                ("FastReadWait", c_ulong),
                ("FastReadResourceMiss", c_ulong),
                ("FastReadNotPossible", c_ulong),
                ("FastMdlReadNoWait", c_ulong),
                ("FastMdlReadWait", c_ulong),
                ("FastMdlReadResourceMiss", c_ulong),
                ("FastMdlReadNotPossible", c_ulong),
                ("MapDataNoWait", c_ulong),
                ("MapDataWait", c_ulong),
                ("MapDataNoWaitMiss", c_ulong),
                ("MapDataWaitMiss", c_ulong),
                ("PinMappedDataCount", c_ulong),
                ("PinReadNoWait", c_ulong),
                ("PinReadWait", c_ulong),
                ("PinReadNoWaitMiss", c_ulong),
                ("PinReadWaitMiss", c_ulong),
                ("CopyReadNoWait", c_ulong),
                ("CopyReadWait", c_ulong),
                ("CopyReadNoWaitMiss", c_ulong),
                ("CopyReadWaitMiss", c_ulong),
                ("MdlReadNoWait", c_ulong),
                ("MdlReadWait", c_ulong),
                ("MdlReadNoWaitMiss", c_ulong),
                ("MdlReadWaitMiss", c_ulong),
                ("ReadAheadIos", c_ulong),
                ("LazyWriteIos", c_ulong),
                ("LazyWritePages", c_ulong),
                ("DataFlushes", c_ulong),
                ("DataPages", c_ulong),
                ("ContextSwitches", c_ulong),
                ("FirstLevelTbFills", c_ulong),
                ("SecondLevelTbFills", c_ulong),
                ("SystemCalls", c_ulong)]

sbi = SYSTEM_BASIC_INFORMATION()
retlen = c_ulong()

res = windll.ntdll.NtQuerySystemInformation(SystemBasicInformation,
                                            byref(sbi),
                                            sizeof(sbi),
                                            byref(retlen))
print res, retlen
print sbi.NumberOfProcessors


spi = SYSTEM_PERFORMANCE_INFORMATION()
retlen = c_ulong()

res = windll.ntdll.NtQuerySystemInformation(SystemPerformanceInformation,
                                            byref(spi),
                                            sizeof(spi),
                                            byref(retlen))
print res, retlen
print spi.PeakCommitment

</snip>

-- 
Thanks,
Thomas


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