diff options
| author | Steven Rostedt <srostedt@redhat.com> | 2011-03-17 15:21:06 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-03-25 11:32:09 +0100 |
| commit | 2092e6be82ec71ecbf5a8ceeef004bbcbdb78812 (patch) | |
| tree | 19dec00f7d1b6e93d9116ec38edba0342b99d689 /include | |
| parent | 71f9e59800e5ad4e6b683348424c9fe54306cd43 (diff) | |
WARN_ON_SMP(): Allow use in if() statements on UP
Both WARN_ON() and WARN_ON_SMP() should be able to be used in
an if statement.
if (WARN_ON_SMP(foo)) { ... }
Because WARN_ON_SMP() is defined as a do { } while (0) on UP,
it can not be used this way.
Convert it to the same form that WARN_ON() is, even when
CONFIG_SMP is off.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <20110317192208.444147791@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-generic/bug.h | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h index c2c9ba032d4..f2d2faf4d9a 100644 --- a/include/asm-generic/bug.h +++ b/include/asm-generic/bug.h @@ -165,10 +165,36 @@ extern void warn_slowpath_null(const char *file, const int line); #define WARN_ON_RATELIMIT(condition, state) \ WARN_ON((condition) && __ratelimit(state)) +/* + * WARN_ON_SMP() is for cases that the warning is either + * meaningless for !SMP or may even cause failures. + * This is usually used for cases that we have + * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked() + * returns 0 for uniprocessor settings. + * It can also be used with values that are only defined + * on SMP: + * + * struct foo { + * [...] + * #ifdef CONFIG_SMP + * int bar; + * #endif + * }; + * + * void func(struct foo *zoot) + * { + * WARN_ON_SMP(!zoot->bar); + * + * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(), + * and should be a nop and return false for uniprocessor. + * + * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set + * and x is true. + */ #ifdef CONFIG_SMP # define WARN_ON_SMP(x) WARN_ON(x) #else -# define WARN_ON_SMP(x) do { } while (0) +# define WARN_ON_SMP(x) ({0;}) #endif #endif |