my code to prove working set larger than virtual bytes

G

George2

Hello everyone,


From the definition of working set, it is a subset of virtual pages
resident in physical memory -- from book Windows Internals. It means
working set could not be larger than virtual memory (subset
relationship).

But the following simple code on Windows Server 2003 proves (if you
monitor virtual bytes counter and working set bytes conuter from
perfmon), if we do not unmap the page map file, the working set will
continue to increase (and much larger than virtual bytes) until we
unmap it.

Take a breakpoint before following code section,

<code>
<pre>
// close mapped files to avoid leak
for (sectionIndex = 0; sectionIndex < size/allocSize; sectionIndex+
+)
{
if (map [sectionIndex])
{
UnmapViewOfFile(map [sectionIndex]);
}
}
</pre>
</code>

Any ideas? Does my code break the definition of working set? Why
working set is much larger than virtual bytes?

<code>
<pre>

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&lt;=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;
}
</pre>
</code>


thanks in advance,
George
 
S

Salt_Peter

Hello everyone,

From the definition of working set, it is a subset of virtual pages
resident in physical memory -- from book Windows Internals. It means
working set could not be larger than virtual memory (subset
relationship).

But the following simple code on Windows Server 2003 proves (if you
monitor virtual bytes counter and working set bytes conuter from
perfmon), if we do not unmap the page map file, the working set will
continue to increase (and much larger than virtual bytes) until we
unmap it.

Take a breakpoint before following code section,

<code>
<pre>
// close mapped files to avoid leak
for (sectionIndex = 0; sectionIndex < size/allocSize; sectionIndex+
+)
{
if (map [sectionIndex])
{
UnmapViewOfFile(map [sectionIndex]);
}
}
</pre>
</code>

Any ideas? Does my code break the definition of working set? Why
working set is much larger than virtual bytes?
Click to expand...

Once again, you are off topic. Thats not an idea - its a fact.
Please ask Windows questions in a Windows newsgroup.
Consult the FAQ in order to redirect your quest to the appropriate
newsgroup.

[5.9] Which newsgroup should I post my questions?
http://www.parashift.com/c++-faq-lite/how-to-post.html#faq-5.9
<code>
<pre>

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;}

</pre>
</code>

thanks in advance,
George
Click to expand...
 
R

red floyd

Salt_Peter said:
[redacted]
Click to expand...

Once again, you are off topic. Thats not an idea - its a fact.
Please ask Windows questions in a Windows newsgroup.
Consult the FAQ in order to redirect your quest to the appropriate
newsgroup.

[5.9] Which newsgroup should I post my questions?
http://www.parashift.com/c++-faq-lite/how-to-post.html#faq-5.9
Click to expand...

I know hope springs eternal, but there's no way this idiot is going to
read the FAQ. He hasn't yet, after being told to multiple times, but
good try anyways.... maybe you'll get him to do it this time.
 
J

jalina

George2 a écrit :
Hello everyone,


From the definition of working set, it is a subset of virtual pages
resident in physical memory -- from book Windows Internals. It means
working set could not be larger than virtual memory (subset
relationship).

But the following simple code on Windows Server 2003 proves (if you
monitor virtual bytes counter and working set bytes conuter from
perfmon), if we do not unmap the page map file, the working set will
continue to increase (and much larger than virtual bytes) until we
unmap it.

Take a breakpoint before following code section,

<code>
<pre>
// close mapped files to avoid leak
for (sectionIndex = 0; sectionIndex < size/allocSize; sectionIndex+
+)
{
if (map [sectionIndex])
{
UnmapViewOfFile(map [sectionIndex]);
}
}
</pre>
</code>

Any ideas? Does my code break the definition of working set? Why
working set is much larger than virtual bytes?

<code>
<pre>

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&lt;=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;
}
</pre>
</code>


thanks in advance,
George
Click to expand...
 
S

Stuart Redmann

red said:
Salt_Peter said:
[redacted]
Click to expand...


Once again, you are off topic. Thats not an idea - its a fact.
Please ask Windows questions in a Windows newsgroup.
Consult the FAQ in order to redirect your quest to the appropriate
newsgroup.

[5.9] Which newsgroup should I post my questions?
http://www.parashift.com/c++-faq-lite/how-to-post.html#faq-5.9
Click to expand...

I know hope springs eternal, but there's no way this idiot is going to
read the FAQ. He hasn't yet, after being told to multiple times, but
good try anyways.... maybe you'll get him to do it this time.
Click to expand...

Has anyone seens George2 sending a reply to one of his topics? As this guy does
not really look trollish, can't it be that he posts to this newsgroup without
realizing it? Maybe his news client has once been configured to automatically
multi-post to various newsgroups, but he has forgotten about it?

I found out that this guy writes as George to microsoft.public.vc.language, too,
opening the same threads, but contrary to this group he sends replies to the
other newsgroup (even making replies to someone else's threads).

Could it simply be that he doesn't even know that he also posts to this
newsgroup, so he never even sees our complaints about his being off-topic?

Stuart
 

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