mm/util.c: add byte count to __vm_enough_memory failure warning
Commit 44b414c8715c5dcf53288 ("mm/util.c: add warning if
__vm_enough_memory fails") adds debug information which gives the process
id and executable name should __vm_enough_memory() fail. Adding the
number of pages to the failure message would benefit application
developers and system administrators in debugging overambitious memory
requests by providing a point of reference to the amount of memory causing
__vm_enough_memory() to fail.
1. Set appropriate kernel tunable to reach code path for failure
message:
# echo 2 > /proc/sys/vm/overcommit_memory
2. Test program to generate failure - requests 1 gibibyte per
iteration:
#include <stdlib.h>
#include <stdio.h>
int main(int argc, char **argv) {
for(;;) {
if(malloc(1<<30) == NULL)
break;
printf("allocated 1 GiB\n");
}
return 0;
}
3. Output:
Before:
__vm_enough_memory: pid: 1218, comm: a.out, not enough memory
for the allocation
After:
__vm_enough_memory: pid: 1137, comm: a.out, bytes: 1073741824,
not enough memory for the allocation
Link: https://lkml.kernel.org/r/20240222194617.1255-1-mcassell411@gmail.com
Signed-off-by: Matthew Cassell <mcassell411@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
1 file changed
