On Tue, Jan 21, 2020 at 1:52 AM Robin Murphy <[email protected]> wrote: > > On 18/12/2019 4:39 am, Cong Wang wrote: > > If the magazine is empty, iova_magazine_free_pfns() should > > be a nop, however it misses the case of mag->size==0. So we > > should just call iova_magazine_empty(). > > > > This should reduce the contention on iovad->iova_rbtree_lock > > a little bit, not much at all. > > Have you measured that in any way? AFAICS the only time this can get > called with a non-full magazine is in the CPU hotplug callback, where > the impact of taking the rbtree lock and immediately releasing it seems > unlikely to be significant on top of everything else involved in that > operation.
This patchset is only tested as a whole, it is not easy to deploy each to production and test it separately. Is there anything wrong to optimize a CPU hotplug path? :) And, it is called in alloc_iova_fast() too when, for example, over-cached. Thanks. _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
