diff mbox series

[31/40] zsmalloc: switch from alloc_vm_area to get_vm_area

Message ID 20201017231517.RsEnw_-y7%akpm@linux-foundation.org (mailing list archive)
State New, archived
Headers show
Series [01/40] ia64: fix build error with !COREDUMP | expand

Commit Message

Andrew Morton Oct. 17, 2020, 11:15 p.m. UTC 
From: Christoph Hellwig <hch@lst.de>
Subject: zsmalloc: switch from alloc_vm_area to get_vm_area

Just manually pre-fault the PTEs using apply_to_page_range.

Link: https://lkml.kernel.org/r/20201002122204.1534411-6-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Co-developed-by: Minchan Kim <minchan@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/zsmalloc.c |   10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
diff mbox series

Patch

--- a/mm/zsmalloc.c~zsmalloc-switch-from-alloc_vm_area-to-get_vm_area
+++ a/mm/zsmalloc.c
@@ -1122,10 +1122,16 @@  static inline int __zs_cpu_up(struct map
 	 */
 	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)