Messages in this thread | | | Subject | Re: [PATCH] Add minimal support for software performance counters for ia64 | From | Peter Zijlstra <> | Date | Wed, 19 Aug 2009 21:06:59 +0200 |
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On Wed, 2009-08-19 at 15:04 -0400, William Cohen wrote: > Peter Zijlstra wrote: > > On Wed, 2009-08-19 at 12:04 -0400, William Cohen wrote: > >> +#ifdef __ia64__ > >> +#include "../../arch/ia64/include/asm/unistd.h" > >> +#define rmb() asm volatile("" ::: "memory") > >> +#define cpu_relax() asm volatile("" ::: "memory"); > >> +#endif > > > > Surely the itanic has a real memory barrier? The kernel seems to use > > something along the lines of mf. > > > > Also, cpu_relax() seems to end up being asm volatile("hint @pause" ::: > > "memory"), although we don't seem to have an actual user of cpu_relax() > > in perf atm. > > > > > > > > Peter, thanks for the comment. I took a look at the rmb() and cpu_relax() code > in the kernel and revised the patch with the appropriate defines
Looks good now, thanks!
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