linux-kernel - [PATCH 03/13] mm: shmem: provide oom badness for shmem files

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Date:   Tue, 31 May 2022 11:59:57 +0200
From:   "Christian König" 
        <ckoenig.leichtzumerken@...il.com>
To:     linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
        intel-gfx@...ts.freedesktop.org, amd-gfx@...ts.freedesktop.org,
        nouveau@...ts.freedesktop.org, linux-tegra@...r.kernel.org,
        linux-fsdevel@...r.kernel.org, linux-mm@...ck.org
Cc:     christian.koenig@....com, alexander.deucher@....com,
        daniel@...ll.ch, viro@...iv.linux.org.uk,
        akpm@...ux-foundation.org, hughd@...gle.com,
        andrey.grodzovsky@....com
Subject: [PATCH 03/13] mm: shmem: provide oom badness for shmem files

This gives the OOM killer an additional hint which processes are
referencing shmem files with potentially no other accounting for them.

Signed-off-by: Christian König <christian.koenig@....com>
---
 mm/shmem.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mm/shmem.c b/mm/shmem.c
index 4b2fea33158e..a4ad92a16968 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2179,6 +2179,11 @@ unsigned long shmem_get_unmapped_area(struct file *file,
 	return inflated_addr;
 }
 
+static long shmem_oom_badness(struct file *file)
+{
+	return i_size_read(file_inode(file)) >> PAGE_SHIFT;
+}
+
 #ifdef CONFIG_NUMA
 static int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *mpol)
 {
@@ -3780,6 +3785,7 @@ EXPORT_SYMBOL(shmem_aops);
 static const struct file_operations shmem_file_operations = {
 	.mmap		= shmem_mmap,
 	.get_unmapped_area = shmem_get_unmapped_area,
+	.oom_badness	= shmem_oom_badness,
 #ifdef CONFIG_TMPFS
 	.llseek		= shmem_file_llseek,
 	.read_iter	= shmem_file_read_iter,
-- 
2.25.1