On Wed, Jul 28, 2021 at 11:38:18AM +0100, John Garry wrote: > On 28/07/2021 02:32, Ming Lei wrote: > > On Mon, Jul 26, 2021 at 3:51 PM John Garry<john.ga...@huawei.com> wrote: > > > On 23/07/2021 11:21, Ming Lei wrote: > > > > > Thanks, I was also going to suggest the latter, since it's what > > > > > arm_smmu_cmdq_issue_cmdlist() does with IRQs masked that should be > > > > > most > > > > > indicative of where the slowness most likely stems from. > > > > The improvement from 'iommu.strict=0' is very small: > > > > > > > Have you tried turning off the IOMMU to ensure that this is really just > > > an IOMMU problem? > > > > > > You can try setting CONFIG_ARM_SMMU_V3=n in the defconfig or passing > > > cmdline param iommu.passthrough=1 to bypass the the SMMU (equivalent to > > > disabling for kernel drivers). > > Bypassing SMMU via iommu.passthrough=1 basically doesn't make a difference > > on this issue. > > A ~90% throughput drop still seems to me to be too high to be a software > issue. More so since I don't see similar on my system. And that throughput > drop does not lead to a total CPU usage drop, from the fio log. > > Do you know if anyone has run memory benchmark tests on this board to find > out NUMA effect? I think lmbench or stream could be used for this.
https://lore.kernel.org/lkml/YOhbc5C47IzC893B@T590/ -- Ming _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
