The commit is pushed to "branch-rh7-3.10.0-229.7.2.vz7.9.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git after rh7-3.10.0-229.7.2.vz7.9.10 ------> commit 4971fe61ca7cf6a282e4407f1a8e390462b46cd3 Author: Peter Zijlstra <pet...@infradead.org> Date: Wed Nov 18 13:23:14 2015 +0400
ms/locking: Remove atomicy checks from {READ, WRITE}_ONCE The fact that volatile allows for atomic load/stores is a special case not a requirement for {READ,WRITE}_ONCE(). Their primary purpose is to force the compiler to emit load/stores _once_. Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Acked-by: Christian Borntraeger <borntrae...@de.ibm.com> Acked-by: Will Deacon <will.dea...@arm.com> Acked-by: Linus Torvalds <torva...@linux-foundation.org> Cc: Davidlohr Bueso <d...@stgolabs.net> Cc: H. Peter Anvin <h...@zytor.com> Cc: Paul McKenney <paul...@linux.vnet.ibm.com> Cc: Stephen Rothwell <s...@canb.auug.org.au> Cc: Thomas Gleixner <t...@linutronix.de> Signed-off-by: Ingo Molnar <mi...@kernel.org> (cherry picked from commit 7bd3e239d6c6d1cad276e8f130b386df4234dcd7) Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> --- include/linux/compiler.h | 16 ---------------- 1 file changed, 16 deletions(-) diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 39fe1dc..2c251f2 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -177,29 +177,16 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); #include <uapi/linux/types.h> -static __always_inline void data_access_exceeds_word_size(void) -#ifdef __compiletime_warning -__compiletime_warning("data access exceeds word size and won't be atomic") -#endif -; - -static __always_inline void data_access_exceeds_word_size(void) -{ -} - static __always_inline void __read_once_size(const volatile void *p, void *res, int size) { switch (size) { case 1: *(__u8 *)res = *(volatile __u8 *)p; break; case 2: *(__u16 *)res = *(volatile __u16 *)p; break; case 4: *(__u32 *)res = *(volatile __u32 *)p; break; -#ifdef CONFIG_64BIT case 8: *(__u64 *)res = *(volatile __u64 *)p; break; -#endif default: barrier(); __builtin_memcpy((void *)res, (const void *)p, size); - data_access_exceeds_word_size(); barrier(); } } @@ -210,13 +197,10 @@ static __always_inline void __assign_once_size(volatile void *p, void *res, int case 1: *(volatile __u8 *)p = *(__u8 *)res; break; case 2: *(volatile __u16 *)p = *(__u16 *)res; break; case 4: *(volatile __u32 *)p = *(__u32 *)res; break; -#ifdef CONFIG_64BIT case 8: *(volatile __u64 *)p = *(__u64 *)res; break; -#endif default: barrier(); __builtin_memcpy((void *)p, (const void *)res, size); - data_access_exceeds_word_size(); barrier(); } } _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel