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@amd.com --- mm/shmem.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/mm/shmem.c b/mm/shmem.c index a6f565308133..b068ac5ba4bf 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2209,6 +2209,21 @@ unsigned long shmem_get_unmapped_area(struct file *file, return inflated_addr; }
+static long shmem_file_rss(struct file *file) +{ + struct inode *inode = file_inode(file); + unsigned long nrpages; + + /* Only account shmem files which aren't part of any fs */ + if (atomic_read(&inode->i_count) > 1) + return 0; + + xa_lock(&file->f_mapping->i_pages); + nrpages = file->f_mapping->nrpages; + xa_unlock(&file->f_mapping->i_pages); + return nrpages; +} + #ifdef CONFIG_NUMA static int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *mpol) { @@ -3811,6 +3826,7 @@ EXPORT_SYMBOL(shmem_aops); static const struct file_operations shmem_file_operations = { .mmap = shmem_mmap, .get_unmapped_area = shmem_get_unmapped_area, + .file_rss = shmem_file_rss, #ifdef CONFIG_TMPFS .llseek = shmem_file_llseek, .read_iter = shmem_file_read_iter,