+ mm-add-warning-if-__vm_enough_memory-fails.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/util.c: add warning if __vm_enough_memory fails
has been added to the -mm mm-unstable branch.  Its filename is
     mm-add-warning-if-__vm_enough_memory-fails.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-add-warning-if-__vm_enough_memory-fails.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: Kefeng Wang <wangkefeng.wang@huawei.com>
Subject: mm/util.c: add warning if __vm_enough_memory fails
Date: Tue, 26 Jul 2022 22:54:28 +0800

If a process has not enough memory to allocate a new virtual mapping, we
may meet verious kinds of error, eg, fork cannot allocate memory, SIGBUS
error in shmem, but it is difficult to confirm them, let's add some debug
information to easily to check this scenario if __vm_enough_memory fails.

Link: https://lkml.kernel.org/r/20220726145428.8030-1-wangkefeng.wang@huawei.com
Reported-by: Yongqiang Liu <liuyongqiang13@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/util.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/mm/util.c~mm-add-warning-if-__vm_enough_memory-fails
+++ a/mm/util.c
@@ -1052,6 +1052,8 @@ 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, no enough memory for the allocation\n",
+			    __func__, current->pid, current->comm);
 	vm_unacct_memory(pages);
 
 	return -ENOMEM;
_

Patches currently in -mm which might be from wangkefeng.wang@huawei.com are

mm-memory-failure-cleanup-try_to_split_thp_page.patch
mm-add-warning-if-__vm_enough_memory-fails.patch