On 11/27/15 at 12:06pm, Joerg Roedel wrote: > On Fri, Nov 06, 2015 at 08:10:45PM +0800, Baoquan He wrote: > > They will be called later when copy old dev/irq tables. It's better to use > > them > > then call iommu_flush_all_caches() since iommu_flush_all_caches() will > > iterate many empty table entries. > > You only flush all table entries on old AMD IOMMUs. Newer ones have a > flush_all command that is used when available. Besides that, the AMD > IOMMU hardware is usually fast so that even flushing all dte entries is > not a bottleneck (it is done during suspend/resume, for example). > > Have you made different experiences?
Since before too many lines of Comopletion-Wait loop timeouts message are printed, especially on my AMD-A10-7850K its last devid is 0xffff. Then it will check and print 0xffff Comopletion-Wait message. So I used this to make it fewer. Now on AMD IOMMU V1 machine I called iommu_enable_command_buffer() earlier and then call iommu_flush_all_caches(iommu), it works well. But on AMD A10-7850K it still printed 0xffff lines of message. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
