The patch titled
Subject: mm/util.c: add page count to __vm_enough_memory failure warning
has been added to the -mm mm-unstable branch. Its filename is
mm-utilc-added-page-count-to-__vm_enough_memory-failure-warning.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-utilc-added-page-count-to-__vm_enough_memory-failure-warning.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Matthew Cassell <mcassell411@xxxxxxxxx>
Subject: mm/util.c: add page count to __vm_enough_memory failure warning
Date: Wed, 21 Feb 2024 16:02:35 +0000
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: 1141, comm: a.out, pages: 262145, not
enough memory for the allocation
Link: https://lkml.kernel.org/r/20240221160235.1771-1-mcassell411@xxxxxxxxx
Signed-off-by: Matthew Cassell <mcassell411@xxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Yongqiang Liu <liuyongqiang13@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/util.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/mm/util.c~mm-utilc-added-page-count-to-__vm_enough_memory-failure-warning
+++ a/mm/util.c
@@ -976,8 +976,8 @@ int __vm_enough_memory(struct mm_struct
if (percpu_counter_read_positive(&vm_committed_as) < allowed)
return 0;
error:
- pr_warn_ratelimited("%s: pid: %d, comm: %s, not enough memory for the allocation\n",
- __func__, current->pid, current->comm);
+ pr_warn_ratelimited("%s: pid: %d, comm: %s, pages: %ld, not enough memory for the allocation\n",
+ __func__, current->pid, current->comm, pages);
vm_unacct_memory(pages);
return -ENOMEM;
_
Patches currently in -mm which might be from mcassell411@xxxxxxxxx are
mm-utilc-added-page-count-to-__vm_enough_memory-failure-warning.patch
