mm/hugetlb: hugetlb_no_page: rate-limit warning message
The warning message "killed due to inadequate hugepage pool" simply
indicates that SIGBUS was sent, not that the process was forcibly killed.
If the process has a signal handler installed does not fix the problem,
this message can rapidly spam the kernel log.
On my amd64 dev machine that does not have hugepages configured, I can
reproduce the repeated warnings easily by setting vm.nr_hugepages=2 (i.e.,
4 megabytes of huge pages) and running something that sets a signal
handler and forks, like
#include <sys/mman.h>
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
sig_atomic_t counter = 10;
void handler(int signal)
{
if (counter-- == 0)
exit(0);
}
int main(void)
{
int status;
char *addr = mmap(NULL, 4 * 1048576, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);
if (addr == MAP_FAILED) {perror("mmap"); return 1;}
*addr = 'x';
switch (fork()) {
case -1:
perror("fork"); return 1;
case 0:
signal(SIGBUS, handler);
*addr = 'x';
break;
default:
*addr = 'x';
wait(&status);
if (WIFSIGNALED(status)) {
psignal(WTERMSIG(status), "child");
}
break;
}
}
Signed-off-by: Geoffrey Thomas <geofft@ldpreload.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 file changed