On 2021/5/19 2:58, Alex Williamson wrote: > On Fri, 9 Apr 2021 11:44:16 +0800 > Shenming Lu <lushenming@xxxxxxxxxx> wrote: > >> To optimize for fewer page fault handlings, we can pre-map more pages >> than requested at once. >> >> Note that IOPF_PREMAP_LEN is just an arbitrary value for now, which we >> could try further tuning. > > I'd prefer that the series introduced full end-to-end functionality > before trying to improve performance. The pre-map value seems > arbitrary here and as noted in the previous patch, the IOMMU API does > not guarantee unmaps of ranges smaller than the original mapping. This > would need to map with single page granularity in order to guarantee > page granularity at the mmu notifier when the IOMMU supports > superpages. Thanks, Yeah, I will drop this patch in the current stage. Thanks, Shenming > > Alex > > . >
