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path: root/drivers/virtio/virtio_balloon.c
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Diffstat (limited to 'drivers/virtio/virtio_balloon.c')
-rw-r--r--drivers/virtio/virtio_balloon.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 510e9318854d..47dce91f788c 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -993,6 +993,23 @@ static int virtballoon_probe(struct virtio_device *vdev)
 			goto out_unregister_oom;
 		}
 
+		/*
+		 * The default page reporting order is @pageblock_order, which
+		 * corresponds to 512MB in size on ARM64 when 64KB base page
+		 * size is used. The page reporting won't be triggered if the
+		 * freeing page can't come up with a free area like that huge.
+		 * So we specify the page reporting order to 5, corresponding
+		 * to 2MB. It helps to avoid THP splitting if 4KB base page
+		 * size is used by host.
+		 *
+		 * Ideally, the page reporting order is selected based on the
+		 * host's base page size. However, it needs more work to report
+		 * that value. The hard-coded order would be fine currently.
+		 */
+#if defined(CONFIG_ARM64) && defined(CONFIG_ARM64_64K_PAGES)
+		vb->pr_dev_info.order = 5;
+#endif
+
 		err = page_reporting_register(&vb->pr_dev_info);
 		if (err)
 			goto out_unregister_oom;