diff mbox series

[05/10] zsmalloc: switch from alloc_vm_area to get_vm_area

Message ID 20200930175133.1252382-6-hch@lst.de (mailing list archive)
State Superseded
Headers show
Series [01/10] mm: update the documentation for vfree | expand

Commit Message

Christoph Hellwig Sept. 30, 2020, 5:51 p.m. UTC 
Just manually pre-fault the PTEs using apply_to_page_range.

Co-developed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 mm/zsmalloc.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index c36fdff9a37131..918c7b019b3d78 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1122,10 +1122,16 @@  static inline int __zs_cpu_up(struct mapping_area *area)
 	 */
 	if (area->vm)
 		return 0;
-	area->vm = alloc_vm_area(PAGE_SIZE * 2, NULL);
+	area->vm = get_vm_area(PAGE_SIZE * 2, 0);
 	if (!area->vm)
 		return -ENOMEM;
-	return 0;
+
+	/*
+	 * Populate ptes in advance to avoid pte allocation with GFP_KERNEL
+	 * in non-preemtible context of zs_map_object.
+	 */
+	return apply_to_page_range(&init_mm, (unsigned long)area->vm->addr,
+			PAGE_SIZE * 2, NULL, NULL);
 }
 
 static inline void __zs_cpu_down(struct mapping_area *area)