George
Thu Jan 17 01:17:00 CST 2008
Thanks Tom,
Here is my program to show the working set could be larger than vritual
bytes. Could you help to double check please? :-)
In the definition of working set, it is the set of pages from virtual memory
pages which physical memory could contain, so working set could not be larger
than virtual bytes -- it is subset relationship.
If you have any ideas why in my application working set is larger than
virtual bytes, or if there is anything wrong, please feel free to let me
know.
Some comments, In my program, I use two ways to hold file map.
1. keep all file map open and close all open handles altogether at the end;
2. close open handle each time after using it.
In (1), working set is much larger than virtual bytes, and in (2).
Here is my code.
#include <windows.h>
#include <stdio.h>
int main(int argc, char* argv[])
{
LARGE_INTEGER start,end;
LARGE_INTEGER freq;
QueryPerformanceCounter(&start);
QueryPerformanceFrequency(&freq);
MEMORYSTATUS memstat;
void** map;
int sectionIndex = 0;
memstat.dwLength = sizeof(memstat);
GlobalMemoryStatus(&memstat);
// basic file mapping test (512 MB)
long long size = 512*1024*1024;
HANDLE mapping =
CreateFileMapping(NULL,NULL,PAGE_READWRITE|SEC_COMMIT,(DWORD)(size>>32),DWORD(size),NULL);
if (mapping)
{
// create and destroy temporary views
SYSTEM_INFO sysInfo;
GetSystemInfo(&sysInfo);
const int allocSize = sysInfo.dwAllocationGranularity;
GlobalMemoryStatus(&memstat);
void *mem = new char[allocSize];
memset(mem,0x11,allocSize);
map = (void**) new char [sizeof(void*) * size / allocSize];
for (int i=0; i<10; i++)
{
sectionIndex = 0;
for (long long offset=0; offset<=size-allocSize; offset+=allocSize)
{
map [sectionIndex] =
MapViewOfFile(mapping,FILE_MAP_WRITE,(DWORD)(offset>>32),(DWORD)offset,allocSize);
if (map [sectionIndex])
{
memcpy(map [sectionIndex],mem,allocSize);
// UnmapViewOfFile(map);
}
sectionIndex++;
} // for (long long offset=0; offset<=size-allocSize; offset+=allocSize)
// close mapped files to avoid leak
for (sectionIndex = 0; sectionIndex < size/allocSize; sectionIndex++)
{
if (map [sectionIndex])
{
UnmapViewOfFile(map [sectionIndex]);
}
}
GlobalMemoryStatus(&memstat);
sectionIndex = 0;
for (long long offset=0; offset<=size-allocSize; offset+=allocSize)
{
map [sectionIndex] =
MapViewOfFile(mapping,FILE_MAP_READ,(DWORD)(offset>>32),(DWORD)offset,allocSize);
if (map [sectionIndex])
{
for (int t=0; t<allocSize; t++)
{
if (((char *)(map [sectionIndex]))[t]!=0x11)
{
OutputDebugString("Memory read failed\n");
}
}
}
UnmapViewOfFile(map [sectionIndex]);
}
// close mapped files to avoid leak
/*
for (sectionIndex = 0; sectionIndex < size/allocSize; sectionIndex++)
{
if (map [sectionIndex])
{
UnmapViewOfFile(map [sectionIndex]);
}
}
*/
GlobalMemoryStatus(&memstat);
} // for (int i=0; i<10; i++)
QueryPerformanceCounter(&end);
GlobalMemoryStatus(&memstat);
printf("Time %.3f\n",
double(end.QuadPart-start.QuadPart)/double(freq.QuadPart));
CloseHandle(mapping);
delete[] mem;
GlobalMemoryStatus(&memstat);
} //if (mapping)
return 0;
}
regards,
George
"Tom Widmer [VC++ MVP]" wrote:
> George wrote:
> > Sorry, Tom!
> >
> >
> > I can not find answers from either the wikipedia link or Google. :-)
> >
> > Let me see if you or others have good ideas.
>
> Can the working set include deallocated pages?
>
> Tom
>
