FRV: work around a possible compiler bug

Work around a possible bug in the FRV compiler.

What appears to be happening is that gcc resolves the
__builtin_constant_p() in kmalloc() to true, but then fails to reduce the
therefore constant conditions in the if-statements it guards to constant
results.

When compiling with -O2 or -Os, one single spurious error crops up in
cpuup_callback() in mm/slab.c.  This can be avoided by making the memsize
variable const.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/frv/Makefile b/arch/frv/Makefile
index 038e3a8457e0b7ad1ad91b46299a1662f6a3a726..9bf7345c5cc93ce90806da9b5d1da62ff6629a27 100644 (file)
--- a/arch/frv/Makefile
+++ b/arch/frv/Makefile
@@ -88,7 +88,7 @@ ASFLAGS               += -mno-fdpic
 # make sure the .S files get compiled with debug info
 # and disable optimisations that are unhelpful whilst debugging
 ifdef CONFIG_DEBUG_INFO
-CFLAGS         += -O1
+#CFLAGS                += -O1
 AFLAGS         += -Wa,--gdwarf2
 ASFLAGS                += -Wa,--gdwarf2
 endif

diff --git a/mm/slab.c b/mm/slab.c
index 96d30ee256efff0e69bf3d0ac6cd51b7ced43e49..88bc6336ce3d3662c897b61a8ca25e33744e31a5 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1163,7 +1163,7 @@ static int __cpuinit cpuup_callback(struct notifier_block *nfb,
        struct kmem_cache *cachep;
        struct kmem_list3 *l3 = NULL;
        int node = cpu_to_node(cpu);
-       int memsize = sizeof(struct kmem_list3);
+       const int memsize = sizeof(struct kmem_list3);
 
        switch (action) {
        case CPU_LOCK_ACQUIRE: