Hello!
Below is simple test case which I think is related to "memory disappear"
problem.
My real program is doing something like this:
// test.c
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
int main(void)
{
int fd;
int r;
char data[10] = "0123456789";
int i;
int end = 30;
for (i=0;i<end;i++) {
fd = open("testfile", O_WRONLY | O_NDELAY | O_TRUNC | O_CREAT, 0644);
if (fd == -1) {
printf("unable to open\n");
return;
}
r = write(fd,data,sizeof data);
if (r == -1) {
printf("unable to write\n");
close(fd);
return;
}
close(fd);
sleep(1);
}
}
// end test.c
Each time I run `free; ./test; free` I see evergrowing memory usage.
I mean used memory + buffers. At some point system just starts swapping
even if no other processes are running. Tested on 2.4.13 and
2.4.17-pre4aa1. I think something is wrong here because the very same
test program does not show such behaviour on 2.2.19. It does not lose
any single byte of memory. I've even tested this on freebsd-4.4 with
the same result as on 2.2.19.
Example output on 2.4.17-pre4aa1:
bash-2.03$ free; ./test; free
total used free shared buffers cached
Mem: 514528 212508 302020 0 7952 150664
-/+ buffers/cache: 53892 460636
Swap: 1028120 0 1028120
total used free shared buffers cached
Mem: 514528 212616 301912 0 8000 150664
-/+ buffers/cache: 53952 460576
Swap: 1028120 0 1028120
bash-2.03$ free; ./test; free
total used free shared buffers cached
Mem: 514528 212616 301912 0 8008 150664
-/+ buffers/cache: 53944 460584
Swap: 1028120 0 1028120
total used free shared buffers cached
Mem: 514528 212700 301828 0 8056 150664
-/+ buffers/cache: 53980 460548
Swap: 1028120 0 1028120
The results are very consistent. I lose 30-40 byte per run.
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