diff options
| author | David Woodhouse <David.Woodhouse@intel.com> | 2012-08-22 12:54:55 +0100 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2012-08-22 12:55:43 +0100 |
| commit | 2361f738b67ab7f1152187fa3d321a09b7c95c09 (patch) | |
| tree | eddf2b958215b668b9b871b6b59bc76c67a47751 /arch/x86/include/asm/bitops.h | |
| parent | 4800399e335658aae632f587f6759a860f584804 (diff) | |
| parent | d9875690d9b89a866022ff49e3fcea892345ad92 (diff) | |
Merge tag 'v3.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux
Having missed the merge window, update to 3.6-rc2 to avoid conflicts with
new patches.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'arch/x86/include/asm/bitops.h')
| -rw-r--r-- | arch/x86/include/asm/bitops.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h index a6983b27722..72f5009deb5 100644 --- a/arch/x86/include/asm/bitops.h +++ b/arch/x86/include/asm/bitops.h @@ -264,6 +264,13 @@ static inline int test_and_clear_bit(int nr, volatile unsigned long *addr) * This operation is non-atomic and can be reordered. * If two examples of this operation race, one can appear to succeed * but actually fail. You must protect multiple accesses with a lock. + * + * Note: the operation is performed atomically with respect to + * the local CPU, but not other CPUs. Portable code should not + * rely on this behaviour. + * KVM relies on this behaviour on x86 for modifying memory that is also + * accessed from a hypervisor on the same CPU if running in a VM: don't change + * this without also updating arch/x86/kernel/kvm.c */ static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) { |