[PATCH V3 2/2] fs/aio.c: use get_user_pages_non_movable() to pin ring pages when support memory hotremove

From: Lin Feng
Date: Thu Feb 21 2013 - 06:03:51 EST

This patch gets around the aio ring pages can't be migrated bug caused by
get_user_pages() via using the new function. It only works as configed with
CONFIG_MEMORY_HOTREMOVE, otherwise it falls back to use the old version
of get_user_pages().

Cc: Benjamin LaHaise <bcrl@xxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Zach Brown <zab@xxxxxxxxxx>
Reviewed-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
Reviewed-by: Gu Zheng <guz.fnst@xxxxxxxxxxxxxx>
Signed-off-by: Lin Feng <linfeng@xxxxxxxxxxxxxx>
fs/aio.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index 2512232..193e145 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -210,8 +210,8 @@ static int aio_setup_ring(struct kioctx *ctx)

pr_debug("mmap address: 0x%08lx\n", ctx->mmap_base);
- ctx->nr_pages = get_user_pages(current, mm, ctx->mmap_base, nr_pages,
- 1, 0, ctx->ring_pages, NULL);
+ ctx->nr_pages = get_user_pages_non_movable(current, mm, ctx->mmap_base,
+ nr_pages, 1, 0, ctx->ring_pages, NULL);

if (unlikely(ctx->nr_pages != nr_pages)) {

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