I did some investigation and when I mmap 2TB memory, the PageDesc is
allocated with 12GB.
The count of PageDesc is about 0x8 and the size of PageDesc is 24Bytes.
So memory costs about 12GB. If the size of PageDesc data is reduced,
the memory should be reduced significantly.
If more and more
Andreas Schwab writes:
> $ cat mmap.c
> #include
> #include
>
> int
> main (void)
> {
> void *A;
> size_t L = 0, U, Max = 0;
> for (U = 1; ; U *= 2)
> {
> A = mmap (0, U, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE,
> -1, 0);
> if (A == (void *) -1)
>
On 9/13/22 10:35, Andreas Schwab wrote:
$ cat mmap.c
#include
#include
int
main (void)
{
void *A;
size_t L = 0, U, Max = 0;
for (U = 1; ; U *= 2)
{
A = mmap (0, U, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE,
-1, 0);
if (A == (void *) -1)
break;
$ cat mmap.c
#include
#include
int
main (void)
{
void *A;
size_t L = 0, U, Max = 0;
for (U = 1; ; U *= 2)
{
A = mmap (0, U, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE,
-1, 0);
if (A == (void *) -1)
break;
else
munmap (A, U);
}
while
