On Wed, 17 Oct 2012, KOSAKI Motohiro wrote: > > I think this refcounting is better than using task_lock(). > > I don't think so. get_vma_policy() is used from fast path. In other > words, number of > atomic ops is sensible for allocation performance.
There are enhancements that we can make with refcounting: for instance, we may want to avoid doing it in the super-fast path when the policy is default_policy and then just do if (mpol != &default_policy) mpol_put(mpol); > Instead, I'd like > to use spinlock > for shared mempolicy instead of mutex. > Um, this was just changed to a mutex last week in commit b22d127a39dd ("mempolicy: fix a race in shared_policy_replace()") so that sp_alloc() can be done with GFP_KERNEL, so I didn't consider reverting that behavior. Are you nacking that patch, which you acked, now? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/