From f27c85c56b32c42bcc54a43189c1e00fdceb23ec Mon Sep 17 00:00:00 2001 From: Hagen Paul Pfeifer Date: Tue, 26 Oct 2010 14:22:21 -0700 Subject: kernel.h: add {min,max}3 macros Introduce two additional min/max macros to compare three operands. This will save some cycles as well as some bytes on the stack and last but not least more pleasing as macro nesting. [akpm@linux-foundation.org: fix warnings] Signed-off-by: Hagen Paul Pfeifer Cc: Joe Perches Cc: Ingo Molnar Cc: Hartley Sweeten Cc: Russell King Cc: Benjamin Herrenschmidt Cc: Thomas Gleixner Cc: Herbert Xu Cc: Roland Dreier Cc: Sean Hefty Cc: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kernel.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index edef168a0406..8e786a27cfe6 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -651,6 +651,24 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } (void) (&_max1 == &_max2); \ _max1 > _max2 ? _max1 : _max2; }) +#define min3(x, y, z) ({ \ + typeof(x) _min1 = (x); \ + typeof(y) _min2 = (y); \ + typeof(z) _min3 = (z); \ + (void) (&_min1 == &_min2); \ + (void) (&_min1 == &_min3); \ + _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \ + (_min2 < _min3 ? _min2 : _min3); }) + +#define max3(x, y, z) ({ \ + typeof(x) _max1 = (x); \ + typeof(y) _max2 = (y); \ + typeof(z) _max3 = (z); \ + (void) (&_max1 == &_max2); \ + (void) (&_max1 == &_max3); \ + _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \ + (_max2 > _max3 ? _max2 : _max3); }) + /** * min_not_zero - return the minimum that is _not_ zero, unless both are zero * @x: value1 -- cgit v1.2.3 From a55621f15bc61826969a29e111ba131a55ef45de Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Tue, 26 Oct 2010 14:22:25 -0700 Subject: include/linux/kernel.h: add __must_check to strict_strto*() The whole point to using the strict functions is to check the return value. If you don't, strict_strto*() will return you uninitialised garbage. Offenders have been observed in the wild. Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kernel.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 8e786a27cfe6..e9b492b33032 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -203,10 +203,10 @@ extern unsigned long simple_strtoul(const char *,char **,unsigned int); extern long simple_strtol(const char *,char **,unsigned int); extern unsigned long long simple_strtoull(const char *,char **,unsigned int); extern long long simple_strtoll(const char *,char **,unsigned int); -extern int strict_strtoul(const char *, unsigned int, unsigned long *); -extern int strict_strtol(const char *, unsigned int, long *); -extern int strict_strtoull(const char *, unsigned int, unsigned long long *); -extern int strict_strtoll(const char *, unsigned int, long long *); +extern int __must_check strict_strtoul(const char *, unsigned int, unsigned long *); +extern int __must_check strict_strtol(const char *, unsigned int, long *); +extern int __must_check strict_strtoull(const char *, unsigned int, unsigned long long *); +extern int __must_check strict_strtoll(const char *, unsigned int, long long *); extern int sprintf(char * buf, const char * fmt, ...) __attribute__ ((format (printf, 2, 3))); extern int vsprintf(char *buf, const char *, va_list) -- cgit v1.2.3 From 77006a0a828249dd69341f960043ee41e7487aa0 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Tue, 26 Oct 2010 14:22:49 -0700 Subject: ratelimit: add comment warning people off printk_ratelimit() printk_ratelimit() was a bad idea - we don't want subsytem A causing ratelimiting of subsystem B's messages. Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kernel.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index e9b492b33032..77b04ed037df 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -277,6 +277,11 @@ asmlinkage int vprintk(const char *fmt, va_list args) asmlinkage int printk(const char * fmt, ...) __attribute__ ((format (printf, 1, 2))) __cold; +/* + * Please don't use printk_ratelimit(), because it shares ratelimiting state + * with all other unrelated printk_ratelimit() callsites. Instead use + * printk_ratelimited() or plain old __ratelimit(). + */ extern int __printk_ratelimit(const char *func); #define printk_ratelimit() __printk_ratelimit(__func__) extern bool printk_timed_ratelimit(unsigned long *caller_jiffies, -- cgit v1.2.3 From 658716d19f8f155c67d4677ba68034b8e492dfbe Mon Sep 17 00:00:00 2001 From: Brian Behlendorf Date: Tue, 26 Oct 2010 14:23:10 -0700 Subject: div64_u64(): improve precision on 32bit platforms The current implementation of div64_u64 for 32bit systems returns an approximately correct result when the divisor exceeds 32bits. Since doing 64bit division using 32bit hardware is a long since solved problem we just use one of the existing proven methods. Additionally, add a div64_s64 function to correctly handle doing signed 64bit division. Addresses https://bugzilla.redhat.com/show_bug.cgi?id=616105 Signed-off-by: Brian Behlendorf Signed-off-by: Oleg Nesterov Cc: Ben Woodard Cc: Jeremy Fitzhardinge Cc: Mark Grondona Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kernel.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 77b04ed037df..450092c1e35f 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -173,6 +173,11 @@ extern int _cond_resched(void); (__x < 0) ? -__x : __x; \ }) +#define abs64(x) ({ \ + s64 __x = (x); \ + (__x < 0) ? -__x : __x; \ + }) + #ifdef CONFIG_PROVE_LOCKING void might_fault(void); #else -- cgit v1.2.3