On Fri, May 22, 2015 at 6:36 AM, Peter Zijlstra <[email protected]> wrote: > On Fri, May 22, 2015 at 06:29:47AM -0700, Stephane Eranian wrote: >> On Fri, May 22, 2015 at 6:25 AM, Peter Zijlstra <[email protected]> wrote: >> > On Fri, May 22, 2015 at 06:07:00AM -0700, Stephane Eranian wrote: >> >> >> >> One other thing I noticed is that the --n_excl needs to be protected by >> >> the >> >> excl_cntrs->lock in put_excl_constraints(). >> > >> > Nah, its strictly per cpu. >> >> No. the excl_cntrs struct is pointed to by cpuc but it is shared between the >> sibling HT. Otherwise this would not work! > > n_excl is per cpuc, see the trickery with has_exclusive vs > exclusive_present on how I avoid the lock.
Yes, but I believe you create a store forward penalty with this. You store 16bits and you load 32 bits on the same cache line. -- 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/
