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Re: Value question (memory consumption) [message #29927 is a reply to message #29916]

Tue, 30 November 2010 13:36

mirek
Messages: 14265
Registered: November 2005

Ultimate Member

andreincx wrote on Mon, 29 November 2010 16:57

Memory consumption is higher with U++ allocator. I've tested with USEMALLOC flag and the memory consumption was half, but has same behavior, only part of the memory is released.

I've modified example to do new allocations and seems that memory get back to OS, at least here on Linux, if i don't use U++ allocator.

#include <Core/Core.h>

using namespace UPP;

#define ITEM_COUNT 1000000

CONSOLE_APP_MAIN {
	Vector<Value> v;
	getchar();
	for(int i=0;i<ITEM_COUNT;i++) v.Add((int)i);
	getchar();
	v.Clear(); v.Shrink();
	getchar();
	for(int i=0;i<ITEM_COUNT;i++) v.Add((int)i);
	getchar();
	v.Clear(); v.Shrink();
	getchar();
}

without U++ allocator:
292 KiB
38.4 MiB
30.8 MiB
38.8 MiB
420 KiB

with U++ allocator:
412 KiB
34.5 MiB (for a sec.) 70.2 MiB maybe Vector double amount of memory it need
62.5 MiB
70.2 MiB
62.5 MiB

Linux 2.6.35-23-generic #40-Ubuntu SMP Wed Nov 17 22:14:33 UTC 2010 x86_64 GNU/Linux

Andrei

In Win32, memory consumption estimated using task manager, it goes like:

USEMALLOC:
724KB
28.2MB
1.1MB
28.2MB
1.2MB

With U++ allocator:
624KB
20.4MB
16.5MB
20.4MB
16.5MB

So the maximum usage is significantly less than for M$ allocator..

I would like to know why Linux is so much higher.

If it is not because of Debug release, we should check the correctnes of core allocation routines in POSIX:

void *SysAllocRaw(size_t size)
{
	sKB += int(((size + 4095) & ~4095) >> 10);
#ifdef PLATFORM_WIN32
	void *ptr = VirtualAlloc(NULL, size, MEM_RESERVE|MEM_COMMIT, PAGE_READWRITE);
#else
#ifdef PLATFORM_LINUX
	void *ptr =  mmap(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
#else
	void *ptr =  mmap(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0);
#endif
	if(ptr == MAP_FAILED)
		ptr = NULL;
#endif
	if(!ptr)
		Panic("Out of memory!");
	DoPeakProfile();
	return ptr;
}

void  SysFreeRaw(void *ptr, size_t size)
{
	sKB -= int(((size + 4095) & ~4095) >> 10);
#ifdef PLATFORM_WIN32
	VirtualFree(ptr, 0, MEM_RELEASE);
#else
	munmap(ptr, size);
#endif
}

int s4kb__;
int s64kb__;

void *AllocRaw4KB()
{
	static int   left;
	static byte *ptr;
	static int   n = 32;
	if(left == 0) {
		left = n >> 5;
		ptr = (byte *)SysAllocRaw(left * 4096);
	}
	n = n + 1;
	if(n > 4096) n = 4096;
	void *p = ptr;
	ptr += 4096;
	left--;
	s4kb__++;
	DoPeakProfile();
	return p;
}

void *AllocRaw64KB()
{
	static int   left;
	static byte *ptr;
	static int   n = 32;
	if(left == 0) {
		left = n >> 5;
		ptr = (byte *)SysAllocRaw(left * 65536);
	}
	n = n + 1;
	if(n > 256) n = 256;
	void *p = ptr;
	ptr += 65536;
	left--;
	s64kb__++;
	DoPeakProfile();
	return p;
}

(the rest is the same for Win32, POSIX):

Mirek

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