On 2017/8/17 22:36, Will Deacon wrote: > Thunder, Nate, Robin, > > On Mon, Jun 26, 2017 at 09:38:45PM +0800, Zhen Lei wrote: >> I described the optimization more detail in patch 1 and 2, and patch 3-5 are >> the implementation on arm-smmu/arm-smmu-v3 of patch 2. >> >> Patch 1 is v2. In v1, I directly replaced writel with writel_relaxed in >> queue_inc_prod. But Robin figured that it may lead SMMU consume stale >> memory contents. I thought more than 3 whole days and got this one. >> >> This patchset is based on Robin Murphy's [PATCH v2 0/8] io-pgtable lock >> removal. > > For the time being, I think we should focus on the new TLB flushing > interface posted by Joerg: > > http://lkml.kernel.org/r/1502974596-23835-1-git-send-email-j...@8bytes.org > > which looks like it can give us most of the benefits of this series. Once > we've got that, we can see what's left in the way of performance and focus > on the cmdq batching separately (because I'm still not convinced about it). OK, this is a good news.
But I have a review comment(sorry, I have not subscribed it yet, so can not directly reply it): I don't think we should add tlb sync for map operation 1. at init time, all tlbs will be invalidated 2. when we try to map a new range, there are no related ptes bufferd in tlb, because of above 1 and below 3 3. when we unmap the above range, make sure all related ptes bufferd in tlb to be invalidated before unmap finished > > Thanks, > > Will > > . > -- Thanks! BestRegards