Messages in this thread | | | Date | Wed, 18 Apr 2001 02:56:45 -0700 | From | Laurent Chavet <> | Subject | Very bad behavior of kswapd |
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Try this (my example I've 2GB of ram)
turn all your swap off
dd about 15% of the size of your RAM: dd if=/dev/zero of=/local/test count=300 bs=1000000
Run this program with SIZE about 95% of your RAM:
#include <stdlib.h> #include <unistd.h> #include <assert.h>
#define SIZE (1900 * 1024 * 1024) int main() { int i; char *p = malloc(SIZE); assert (p != NULL); for (i = 0; i < SIZE; i++) p[i] = 1; printf ("done %p\n", p);
while (1) { sleep (60); } return 0; }
Watch top: when this program needs the memory that kswapd keep in cache they go both at 100% cpu (on SMP) but still the size of the program only grows at about 100KB/s, why is kswapd releasing it so slowly and taking so much CPU ?
Laurent Chavet
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