On Sun, 16 Jun 2013 08:01:44 -1000 Linus Torvalds <[email protected]> wrote:
> On Sat, Jun 15, 2013 at 10:36 PM, Geert Uytterhoeven > <[email protected]> wrote: > > > > On Sun, Jun 16, 2013 at 12:12 AM, Linus Torvalds > > <[email protected]> wrote: > > > David Daney (3): > > > smp.h: Use local_irq_{save,restore}() in !SMP version of > > > on_each_cpu(). > > > > This change (commit f21afc25f9ed45b8ffe200d0f071b0caec3ed2ef, which hasn't > > been in linux-next), broke at least mn10300 and ia64: > > > > include/linux/smp.h:148:2: error: implicit declaration of function > > 'local_irq_save' [-Werror=implicit-function-declaration] > > Hmm. DavidD already added the include for <linux/irqflags.h>, I wonder > why that doesn't end up working. Do we have some silly header file > circular include that means that we're already half-way through that > irqflags.h file and thus will skip it the second time we see it, or > why does it end up being undeclared? Heaven knows; I don't think now is the time to try to fix this. If I'd thought for two seconds I wouldn't have sent that patch at this time - additional low-level includes in low-level header files are often problematic. > Anyway, I see a few options: > > - we could just make it a macro like it used to be (keeping the > include and assuming that will sort out any circular include mess) and > use a rare name for the internal "flags" variable (just prepending > double underscores is the common one we tend to use in situations like > this) > > - we could just make it a real function, the way the SMP one is, and > take the extra call overhead (it's not like this should be all that > critical in an UP environment). > > - somebody figures out why the <linux/irqflags.h> include ends up not > working on nm10300 and ia64.. Methinks we should fight this battle at a later date. I queued this: From: Andrew Morton <[email protected]> Subject: include/linux/smp.h:on_each_cpu(): switch back to a macro f21afc25f9ed4 ("smp.h: Use local_irq_{save,restore}() in !SMP version of on_each_cpu()") converted on_each_cpu() to a C function. This required inclusion of irqflags.h, which broke ia64 and mn10300 (at least) due to header ordering hell. Switch on_each_cpu() back to a macro to fix this. Reported-by: Geert Uytterhoeven <[email protected]> Cc: David Daney <[email protected]> Cc: Ralf Baechle <[email protected]> Signed-off-by: Andrew Morton <[email protected]> --- include/linux/smp.h | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff -puN include/linux/smp.h~include-linux-smph-on_each_cpu-switch-back-to-a-macro include/linux/smp.h --- a/include/linux/smp.h~include-linux-smph-on_each_cpu-switch-back-to-a-macro +++ a/include/linux/smp.h @@ -11,7 +11,6 @@ #include <linux/list.h> #include <linux/cpumask.h> #include <linux/init.h> -#include <linux/irqflags.h> extern void cpu_idle(void); @@ -140,17 +139,14 @@ static inline int up_smp_call_function(s } #define smp_call_function(func, info, wait) \ (up_smp_call_function(func, info)) - -static inline int on_each_cpu(smp_call_func_t func, void *info, int wait) -{ - unsigned long flags; - - local_irq_save(flags); - func(info); - local_irq_restore(flags); - return 0; -} - +#define on_each_cpu(func,info,wait) \ + ({ \ + unsigned long flags; \ + local_irq_save(flags); \ + func(info); \ + local_irq_restore(flags); \ + 0; \ + }) /* * Note we still need to test the mask even for UP * because we actually can get an empty mask from _ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
