+ maple_tree-use-mas_node_count_gfp-on-mas_expected_entries.patch added to mm-hotfixes-unstable branch

+ maple_tree-use-mas_node_count_gfp-on-mas_expected_entries.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: maple_tree: use mas_node_count_gfp() in mas_expected_entries()
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     maple_tree-use-mas_node_count_gfp-on-mas_expected_entries.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-use-mas_node_count_gfp-on-mas_expected_entries.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Jaeseon Sim <jason.sim@samsung.com>
Subject: maple_tree: use mas_node_count_gfp() in mas_expected_entries()
Date: Fri, 15 Sep 2023 18:32:43 +0900

Use mas_node_count_gfp with GFP_KERNEL instead of
GFP_NOWAIT | __GFP_NOWARN on mas_expected_entries
in order to allow memory reclaim.

Currently, fork errors occur on low free memory as follows:

 Zygote  : Failed to fork child process: Out of memory (12)

-ENOMEM was returned as following path:

 mas_node_count
 mas_expected_entries
 dup_mmap
 dup_mm
 copy_mm
 copy_process

Link: https://lkml.kernel.org/r/20230915093243epcms1p46fa00bbac1ab7b7dca94acb66c44c456@epcms1p4
Signed-off-by: Jaeseon Sim <jason.sim@samsung.com>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/maple_tree.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/lib/maple_tree.c~maple_tree-use-mas_node_count_gfp-on-mas_expected_entries
+++ a/lib/maple_tree.c
@@ -5574,7 +5574,7 @@ int mas_expected_entries(struct ma_state
 	/* Internal nodes */
 	nr_nodes += DIV_ROUND_UP(nr_nodes, nonleaf_cap);
 	/* Add working room for split (2 nodes) + new parents */
-	mas_node_count(mas, nr_nodes + 3);
+	mas_node_count_gfp(mas, nr_nodes + 3, GFP_KERNEL);
 
 	/* Detect if allocations run out */
 	mas->mas_flags |= MA_STATE_PREALLOC;
_

Patches currently in -mm which might be from jason.sim@samsung.com are

maple_tree-use-mas_node_count_gfp-on-mas_expected_entries.patch