mm: slab: remove ZONE_DMA_FLAG

Now we have IS_ENABLED helper to check if a Kconfig option is enabled or
not, so ZONE_DMA_FLAG sounds no longer useful.

And, the use of ZONE_DMA_FLAG in slab looks pointless according to the
comment [1] from Johannes Weiner, so remove them and ORing passed in
flags with the cache gfp flags has been done in kmem_getpages().

[1] https://lkml.org/lkml/2014/9/25/553

Link: http://lkml.kernel.org/r/1462381297-11009-1-git-send-email-yang.shi@linaro.org
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/Kconfig b/mm/Kconfig
index 989f8f3d77e0d7bf552a008f5aee227a5c3ddcd0..d6e9042b99e038dac0434031e6b1a7432671460c 100644 (file)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -268,11 +268,6 @@ config ARCH_ENABLE_HUGEPAGE_MIGRATION
 config PHYS_ADDR_T_64BIT
        def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT
 
-config ZONE_DMA_FLAG
-       int
-       default "0" if !ZONE_DMA
-       default "1"
-
 config BOUNCE
        bool "Enable bounce buffers"
        default y

diff --git a/mm/slab.c b/mm/slab.c
index 1ee26a0d358fad7b9d9ba4de098fb6e424420a75..d81565a92864b3171e29c56d23e4cfe063df2883 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2236,7 +2236,7 @@ done:
        cachep->freelist_size = cachep->num * sizeof(freelist_idx_t);
        cachep->flags = flags;
        cachep->allocflags = __GFP_COMP;
-       if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
+       if (flags & SLAB_CACHE_DMA)
                cachep->allocflags |= GFP_DMA;
        cachep->size = size;
        cachep->reciprocal_buffer_size = reciprocal_value(size);
@@ -2664,16 +2664,6 @@ static void cache_init_objs(struct kmem_cache *cachep,
        }
 }
 
-static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
-{
-       if (CONFIG_ZONE_DMA_FLAG) {
-               if (flags & GFP_DMA)
-                       BUG_ON(!(cachep->allocflags & GFP_DMA));
-               else
-                       BUG_ON(cachep->allocflags & GFP_DMA);
-       }
-}
-
 static void *slab_get_obj(struct kmem_cache *cachep, struct page *page)
 {
        void *objp;
@@ -2752,14 +2742,6 @@ static struct page *cache_grow_begin(struct kmem_cache *cachep,
        if (gfpflags_allow_blocking(local_flags))
                local_irq_enable();
 
-       /*
-        * The test for missing atomic flag is performed here, rather than
-        * the more obvious place, simply to reduce the critical path length
-        * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
-        * will eventually be caught here (where it matters).
-        */
-       kmem_flagcheck(cachep, flags);
-
        /*
         * Get mem for the objs.  Attempt to allocate a physical page from
         * 'nodeid'.
@@ -3145,9 +3127,6 @@ static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
                                                gfp_t flags)
 {
        might_sleep_if(gfpflags_allow_blocking(flags));
-#if DEBUG
-       kmem_flagcheck(cachep, flags);
-#endif
 }
 
 #if DEBUG