From 0b59c25f91002c1dec0d0d848e5aaefa5f213c85 Mon Sep 17 00:00:00 2001 From: Igor Stoppa Date: Fri, 31 Aug 2018 22:44:22 +0300 Subject: mm: percpu: remove unnecessary unlikely() WARN_ON() already contains an unlikely(), so it's not necessary to wrap it into another. Signed-off-by: Igor Stoppa Cc: Tejun Heo Cc: zijun_hu Cc: Christoph Lameter Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Dennis Zhou --- mm/percpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/percpu.c b/mm/percpu.c index a749d4d96e3e..f5c2796fe63e 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -2588,7 +2588,7 @@ int __init pcpu_page_first_chunk(size_t reserved_size, BUG_ON(ai->nr_groups != 1); upa = ai->alloc_size/ai->unit_size; nr_g0_units = roundup(num_possible_cpus(), upa); - if (unlikely(WARN_ON(ai->groups[0].nr_units != nr_g0_units))) { + if (WARN_ON(ai->groups[0].nr_units != nr_g0_units)) { pcpu_free_alloc_info(ai); return -EINVAL; } -- cgit v1.2.3 From b5bb425871186303e6936fa2581521bdd1964a58 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Tue, 25 Sep 2018 12:44:59 -0700 Subject: arm64: percpu: Initialize ret in the default case Clang warns that if the default case is taken, ret will be uninitialized. ./arch/arm64/include/asm/percpu.h:196:2: warning: variable 'ret' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized] default: ^~~~~~~ ./arch/arm64/include/asm/percpu.h:200:9: note: uninitialized use occurs here return ret; ^~~ ./arch/arm64/include/asm/percpu.h:157:19: note: initialize the variable 'ret' to silence this warning unsigned long ret, loop; ^ = 0 This warning appears several times while building the erofs filesystem. While it's not strictly wrong, the BUILD_BUG will prevent this from becoming a true problem. Initialize ret to 0 in the default case right before the BUILD_BUG to silence all of these warnings. Reported-by: Prasad Sodagudi Signed-off-by: Nathan Chancellor Reviewed-by: Nick Desaulniers Signed-off-by: Dennis Zhou --- arch/arm64/include/asm/percpu.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/include/asm/percpu.h b/arch/arm64/include/asm/percpu.h index 9234013e759e..21a81b59a0cc 100644 --- a/arch/arm64/include/asm/percpu.h +++ b/arch/arm64/include/asm/percpu.h @@ -96,6 +96,7 @@ static inline unsigned long __percpu_##op(void *ptr, \ : [val] "Ir" (val)); \ break; \ default: \ + ret = 0; \ BUILD_BUG(); \ } \ \ @@ -125,6 +126,7 @@ static inline unsigned long __percpu_read(void *ptr, int size) ret = READ_ONCE(*(u64 *)ptr); break; default: + ret = 0; BUILD_BUG(); } @@ -194,6 +196,7 @@ static inline unsigned long __percpu_xchg(void *ptr, unsigned long val, : [val] "r" (val)); break; default: + ret = 0; BUILD_BUG(); } -- cgit v1.2.3