diff options
| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-08-06 09:48:31 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-08-06 09:48:31 -0700 |
| commit | c87985a3ce723995fc7b25e598238d67154108a1 (patch) | |
| tree | e60def1b77c25c1d74180f62e8a5603f9826f209 /arch/x86/include/asm/bitops.h | |
| parent | d155255a344c417acad74156654295a2964e6b81 (diff) | |
| parent | 0d7614f09c1ebdbaa1599a5aba7593f147bf96ee (diff) | |
Merge tty-next into 3.6-rc1
This handles the merge issue in:
arch/um/drivers/line.c
arch/um/drivers/line.h
And resolves the duplicate patches that were in both trees do to the
tty-next branch not getting merged into 3.6-rc1.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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) { |