From 18cb2aef91b37dbce2bec2f39bb1dddd0e9dd838 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Sat, 7 Aug 2010 03:26:23 +0900 Subject: [PATCH 1/4] percpu: handle __percpu notations in UP accessors UP accessors didn't take care of __percpu notations leading to a lot of spurious sparse warnings on UP configurations. Fix it. Signed-off-by: Namhyung Kim Signed-off-by: Tejun Heo --- include/asm-generic/percpu.h | 15 ++++++++++----- include/linux/percpu.h | 2 +- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h index b5043a9890d8..08923b684768 100644 --- a/include/asm-generic/percpu.h +++ b/include/asm-generic/percpu.h @@ -70,11 +70,16 @@ extern void setup_per_cpu_areas(void); #else /* ! SMP */ -#define per_cpu(var, cpu) (*((void)(cpu), &(var))) -#define __get_cpu_var(var) (var) -#define __raw_get_cpu_var(var) (var) -#define this_cpu_ptr(ptr) per_cpu_ptr(ptr, 0) -#define __this_cpu_ptr(ptr) this_cpu_ptr(ptr) +#define VERIFY_PERCPU_PTR(__p) ({ \ + __verify_pcpu_ptr((__p)); \ + (typeof(*(__p)) __kernel __force *)(__p); \ +}) + +#define per_cpu(var, cpu) (*((void)(cpu), VERIFY_PERCPU_PTR(&(var)))) +#define __get_cpu_var(var) (*VERIFY_PERCPU_PTR(&(var))) +#define __raw_get_cpu_var(var) (*VERIFY_PERCPU_PTR(&(var))) +#define this_cpu_ptr(ptr) per_cpu_ptr(ptr, 0) +#define __this_cpu_ptr(ptr) this_cpu_ptr(ptr) #endif /* SMP */ diff --git a/include/linux/percpu.h b/include/linux/percpu.h index b8b9084527b1..49466b13c5c6 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -149,7 +149,7 @@ extern void __init percpu_init_late(void); #else /* CONFIG_SMP */ -#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); }) +#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); VERIFY_PERCPU_PTR((ptr)); }) /* can't distinguish from other static vars, always false */ static inline bool is_kernel_percpu_address(unsigned long addr) From 94cb121c9483f1ec9b1ef0c249fbfc49c628fa6b Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Sat, 7 Aug 2010 03:26:24 +0900 Subject: [PATCH 2/4] percpu: add __percpu notations to UP allocator Add __percpu notations to UP percpu allocator. Signed-off-by: Namhyung Kim Signed-off-by: Tejun Heo --- mm/percpu_up.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/percpu_up.c b/mm/percpu_up.c index c4351c7f57d2..db884fae5721 100644 --- a/mm/percpu_up.c +++ b/mm/percpu_up.c @@ -14,13 +14,13 @@ void __percpu *__alloc_percpu(size_t size, size_t align) * percpu sections on SMP for which this path isn't used. */ WARN_ON_ONCE(align > SMP_CACHE_BYTES); - return kzalloc(size, GFP_KERNEL); + return (void __percpu __force *)kzalloc(size, GFP_KERNEL); } EXPORT_SYMBOL_GPL(__alloc_percpu); void free_percpu(void __percpu *p) { - kfree(p); + kfree(this_cpu_ptr(p)); } EXPORT_SYMBOL_GPL(free_percpu); From a002d148426f40bc2b7dc066982eb177cdebeaaa Mon Sep 17 00:00:00 2001 From: Huang Shijie Date: Sun, 8 Aug 2010 14:39:07 +0200 Subject: [PATCH 3/4] percpu: fix a memory leak in pcpu_extend_area_map() The original code did not free the old map. This patch fixes it. tj: use @old as memcpy source instead of @chunk->map, and indentation and description update Signed-off-by: Huang Shijie Signed-off-by: Tejun Heo Cc: stable@kernel.org --- mm/percpu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/percpu.c b/mm/percpu.c index e61dc2cc5873..a1830d8e3318 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -393,7 +393,9 @@ static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc) goto out_unlock; old_size = chunk->map_alloc * sizeof(chunk->map[0]); - memcpy(new, chunk->map, old_size); + old = chunk->map; + + memcpy(new, old, old_size); chunk->map_alloc = new_alloc; chunk->map = new; From 54157c44471f5e266508ac08d270f2bc5857e8bb Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Wed, 11 Aug 2010 11:19:19 +0900 Subject: [PATCH 4/4] percpu: fix a mismatch between code and comment When pcpu_build_alloc_info() searches best_upa value, it ignores current value if the number of waste units exceeds 1/3 of the number of total cpus. But the comment on the code says that it will ignore if wastage is over 25%. Modify the comment. Signed-off-by: Namhyung Kim Signed-off-by: Tejun Heo --- mm/percpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/percpu.c b/mm/percpu.c index a1830d8e3318..58c572b18b07 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1164,7 +1164,7 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info( } /* - * Don't accept if wastage is over 25%. The + * Don't accept if wastage is over 1/3. The * greater-than comparison ensures upa==1 always * passes the following check. */