[dm-devel] [PATCH] dm: use __GFP_HIGHMEM in __vmalloc

[Mikulas Patocka]

dm: use __GFP_HIGHMEM in __vmalloc

Pages allocated with __vmalloc can be allocated in high memory that is not
directly mapped to kernel space, so use __GFP_HIGHMEM just like vmalloc
does. This patch reduces memory pressure slightly because pages can be
allocated in the high zone.

Signed-off-by: Mikulas Patocka <mpatocka at redhat.com>

---
 drivers/md/dm-bufio.c |    2 
 drivers/md/dm-ioctl.c |  189 +++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 188 insertions(+), 3 deletions(-)

Index: linux-3.9.5-fast/drivers/md/dm-bufio.c
===================================================================
--- linux-3.9.5-fast.orig/drivers/md/dm-bufio.c	2013-06-09 01:16:45.000000000 +0200
+++ linux-3.9.5-fast/drivers/md/dm-bufio.c	2013-06-09 01:20:24.000000000 +0200
@@ -350,7 +350,7 @@ static void *alloc_buffer_data(struct dm
 	if (gfp_mask & __GFP_NORETRY)
 		noio_flag = memalloc_noio_save();
 
-	ptr = __vmalloc(c->block_size, gfp_mask, PAGE_KERNEL);
+	ptr = __vmalloc(c->block_size, gfp_mask | __GFP_HIGHMEM, PAGE_KERNEL);
 
 	if (gfp_mask & __GFP_NORETRY)
 		memalloc_noio_restore(noio_flag);
Index: linux-3.9.5-fast/drivers/md/dm-ioctl.c
===================================================================
--- linux-3.9.5-fast.orig/drivers/md/dm-ioctl.c	2013-06-09 01:20:14.000000000 +0200
+++ linux-3.9.5-fast/drivers/md/dm-ioctl.c	2013-06-09 01:20:32.000000000 +0200
@@ -1688,7 +1873,7 @@ static int copy_params(struct dm_ioctl _
 	if (!dmi) {
 		unsigned noio_flag;
 		noio_flag = memalloc_noio_save();
-		dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH, PAGE_KERNEL);
+		dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL);
 		memalloc_noio_restore(noio_flag);
 		if (dmi)
 			*param_flags |= DM_PARAMS_VMALLOC;