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.garry@xxxxxxxxxx> wrote:
On 23/07/2021 11:21, Ming Lei wrote:Bypassing SMMU via iommu.passthrough=1 basically doesn't make a difference
Have you tried turning off the IOMMU to ensure that this is really justThanks, I was also going to suggest the latter, since it's whatThe improvement from 'iommu.strict=0' is very small:
arm_smmu_cmdq_issue_cmdlist() does with IRQs masked that should be most
indicative of where the slowness most likely stems from.
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).
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/