Revert "mm: fail GFP_DMA allocations when ZONE_DMA is not configured"

This reverts commit a197b59ae6e8bee56fcef37ea2482dc08414e2ac.

As rmk says:
 "Commit a197b59ae6e8 (mm: fail GFP_DMA allocations when ZONE_DMA is not
  configured) is causing regressions on ARM with various drivers which
  use GFP_DMA.

  The behaviour up until now has been to silently ignore that flag when
  CONFIG_ZONE_DMA is not enabled, and to allocate from the normal zone.
  However, as a result of the above commit, such allocations now fail
  which causes drivers to fail.  These are regressions compared to the
  previous kernel version."

so just revert it.

Requested-by: Russell King <linux@arm.linux.org.uk>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a4e1db3..4e8985a 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2247,10 +2247,6 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 
        if (should_fail_alloc_page(gfp_mask, order))
                return NULL;
-#ifndef CONFIG_ZONE_DMA
-       if (WARN_ON_ONCE(gfp_mask & __GFP_DMA))
-               return NULL;
-#endif
 
        /*
         * Check the zones suitable for the gfp_mask contain at least one