mm/slob: use min_t() to compare ARCH_SLAB_MINALIGN

The definition of ARCH_SLAB_MINALIGN is architecture dependent
and can be either of type size_t or int. Comparing that value
with ARCH_KMALLOC_MINALIGN can cause harmless warnings on
platforms where they are different. Since both are always
small positive integer numbers, using the size_t type to compare
them is safe and gets rid of the warning.

Without this patch, building ARM collie_defconfig results in:

mm/slob.c: In function '__kmalloc_node':
mm/slob.c:431:152: warning: comparison of distinct pointer types lacks a cast [enabled by default]
mm/slob.c: In function 'kfree':
mm/slob.c:484:153: warning: comparison of distinct pointer types lacks a cast [enabled by default]
mm/slob.c: In function 'ksize':
mm/slob.c:503:153: warning: comparison of distinct pointer types lacks a cast [enabled by default]

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[ penberg@kernel.org: updates for master ]
Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/mm/slob.c b/mm/slob.c
index e7d7901..87e16c4 100644 (file)
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -428,7 +428,7 @@ static __always_inline void *
 __do_kmalloc_node(size_t size, gfp_t gfp, int node, unsigned long caller)
 {
        unsigned int *m;
-       int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
+       int align = max_t(size_t, ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
        void *ret;
 
        gfp &= gfp_allowed_mask;
@@ -496,7 +496,7 @@ void kfree(const void *block)
 
        sp = virt_to_page(block);
        if (PageSlab(sp)) {
-               int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
+               int align = max_t(size_t, ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
                unsigned int *m = (unsigned int *)(block - align);
                slob_free(m, *m + align);
        } else
@@ -519,7 +519,7 @@ size_t ksize(const void *block)
        if (unlikely(!PageSlab(sp)))
                return PAGE_SIZE << compound_order(sp);
 
-       align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
+       align = max_t(size_t, ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
        m = (unsigned int *)(block - align);
        return SLOB_UNITS(*m) * SLOB_UNIT;
 }