[PATCH 04/13] dma-buf: provide oom badness for DMA-buf files

From: Christian König
Date: Tue May 31 2022 - 06:00:46 EST


For now just return the size of the DMA-buf in pages as badness in the
OOM situation. That should probably be extended to be in control of the
exporter in the future.

Signed-off-by: Christian König <christian.koenig@xxxxxxx>
---
drivers/dma-buf/dma-buf.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index a2f9a1815e38..bdd4e8767cd3 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -388,6 +388,12 @@ static void dma_buf_show_fdinfo(struct seq_file *m, struct file *file)
spin_unlock(&dmabuf->name_lock);
}

+static long dma_buf_oom_badness(struct file *file)
+{
+ /* TODO: This should probably be controlled by a flag */
+ return i_size_read(file_inode(file)) >> PAGE_SHIFT;
+}
+
static const struct file_operations dma_buf_fops = {
.release = dma_buf_file_release,
.mmap = dma_buf_mmap_internal,
@@ -396,6 +402,7 @@ static const struct file_operations dma_buf_fops = {
.unlocked_ioctl = dma_buf_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.show_fdinfo = dma_buf_show_fdinfo,
+ .oom_badness = dma_buf_oom_badness,
};

/*
--
2.25.1