7.8 KiB
Python:在 Windows 中查找提交费用值
原文：https://www.blog.pythonlibrary.org/2010/03/05/python-finding-the-commit-charge-values-in-windows/
本周，我的任务是设法找出我们虚拟工作站上的峰值提交值。原因是我们试图节省资金，并想知道我们是否分配了太多的内存。我们不需要总提交费用或限制提交费用值，但是由于我在研究中已经知道如何获得这些值，所以我也将展示如何获得这些值。
当我第一次开始搜索这个主题时，我尝试了诸如“python 峰值提交值”及其变体这样的搜索术语。这让我一无所获，所以我用“wmi”替换了“oython ”,并在 MSDN 上找到了Win32 _ performatteddata _ perfs _ Memory类。我以为这就是了，但它只给了我提交费用限额和总提交费用。下面是我如何使用蒂姆·戈登的 WMI 模块得到这些值的:
import wmi
c = wmi.WMI()
for item in c.Win32_PerfFormattedData_PerfOS_Memory():
commitChargeLimit = int(item.CommitLimit) / 1024
for item in c.Win32_PerfFormattedData_PerfOS_Memory():
commitChargeTotal = int(item.CommittedBytes) / 1024
print "Commit Charge Limit: ", commitChargeLimit
print "Commit Charge Total: ", commitChargeTotal
这是很好的东西，显示了在 MSDN 获取文档并将其翻译成可用的 Python 语言是多么容易。不幸的是，它并没有给我所需要的信息。我的下一站是 PyWin32 邮件列表，Mark Hammond 在那里告诉我 win32pdh 和 win32pdhutil 模块。这些公开了性能计数器，但是我也找不到使用它来获取这些信息的方法。幸运的是，我在 sysinternals 论坛上找到了一个旧帖子，给了我一个线索。它是这样说的:
据我所知，获得这一细节的唯一方法是从 SYSTEM_PERFORMANCE_INFORMATION 结构的 uMmPeakCommitLimit 成员中获取，当使用 SystemPerformanceInformation 类型调用它时，会将该成员传递给 NtQuerySystemInformation。
我问哈蒙德先生这是否意味着我需要使用 ctypes ，因为 NtQuerySystemInformation 类没有被 PyWin32 公开，他说“可能”。ctypes 模块非常低级，除了从 ActiveState 复制脚本时，我没有用过它。这是一个非常方便的模块，在 2.5 版本中被添加到了标准库中。据我所知，它是由托马斯·海勒创作的。
反正 ctypes 有自己的邮件列表，所以我决定去那里试试。我收到了两个回复，其中一个是那个人本人(海勒)。他给了我一个剧本，开始看起来不太管用，但是和他反复讨论之后，他把我弄明白了。结果如下:
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 "Peak commit: ",
print spi.PeakCommitment * 4096 / 1024
我真的不明白这里发生的一切，但我很高兴它起作用了。嗯，我应该说它在 Windows XP Professional 上工作，32 位，Python 2.5。我在 64 位的 Windows 7 上也尝试过，当脚本运行时，它返回“0L”。我猜 64 位操作系统需要稍微不同的脚本，但是因为我们所有的工作站目前都使用 32 位，所以这一点并不重要。Python 社区再一次帮助了我，向我展示了他们有多棒！