How to find the current System Cache Size on Windows?

Question

Searched high and low but haven't been able to find an API call to retrieve the current size of the (File) System Cache on Windows.

GlobalMemoryStatusEx - retrieves the Total, Free, Used, and Swap stats.

GetSystemFileCacheSize - returns the Minimum and Maximum it could be, not very helpful.

I also tried the Windows extensions, which returned the unhelpful numbers below. Looks like it could be anywhere from 1mb to 2gb?

>>> import win32api
>>> win32api.GetSystemFileCacheSize()
(1048576L, 2143289344L, 0L)

What is the correct API call to get this information? I see it available in the task manager, so it must be in there somewhere? Here's a screen shot and the numbers I'm looking for:

enter image description here

Would prefer a python solution, but C/C++ would help a lot.

You can try to get programmatically 4 performance counters `Cached` = `\Memory\Modified Page List Bytes` + `\Memory\Standby Cache Reserve Bytes` + `\Memory\Standby Cache Normal Priority Bytes` + `\Memory\Standby Cache Core Bytes` — Serg, Jan 17 '13 at 07:51
Thanks for your help. I wasn't able to find an api call after many hours of searching. Looking up these perf counters and why they didn't match the task manager led me to a mailing list where a post pointed to the call below. ;) — Gringo Suave, Jan 18 '13 at 10:15

score 2 · Answer 1 · edited Mar 31 '15 at 22:14

I did finally figure it out:

import ctypes
psapi = ctypes.WinDLL('psapi')

class PERFORMANCE_INFORMATION(ctypes.Structure):
    ''' Struct for Windows .GetPerformanceInfo().
        http://msdn.microsoft.com/en-us/library/ms683210
    '''

    _DWORD = ctypes.c_ulong
    _SIZE_T = ctypes.c_size_t

    _fields_ = [
        ('cb', _DWORD),
        ('CommitTotal', _SIZE_T),
        ('CommitLimit', _SIZE_T),
        ('CommitPeak', _SIZE_T),
        ('PhysicalTotal', _SIZE_T),
        ('PhysicalAvailable', _SIZE_T),
        ('SystemCache', _SIZE_T),
        ('KernelTotal', _SIZE_T),
        ('KernelPaged', _SIZE_T),
        ('KernelNonpaged', _SIZE_T),
        ('PageSize', _SIZE_T),
        ('HandleCount', _DWORD),
        ('ProcessCount', _DWORD),
        ('ThreadCount', _DWORD),
    ]

    def __init__(self, getinfo=True, *args, **kwds):
        super(PERFORMANCE_INFORMATION, self).__init__(
              ctypes.sizeof(self), *args, **kwds)
        if (getinfo and not
            psapi.GetPerformanceInfo(ctypes.byref(self), 
                                     self.cb)):
            raise WinError()

    @property
    def cache_info(self):
        return self.SystemCache * self.PageSize

def get_cache_info():
    return PERFORMANCE_INFORMATION().cache_info

if __name__ == '__main__':
    print(get_cache_info())

How to find the current System Cache Size on Windows?

1 Answers1

Linked