Re: [bug report] iommu_dma_unmap_sg() is very slow then running IO from remote numa node
From: John Garry <hidden>
Date: 2021-07-22 13:54:56
Also in:
linux-iommu, linux-nvme, lkml
On 22/07/2021 13:53, Marc Zyngier wrote:
Hi John, [...]quoted
Your kernel log should show: [ 0.000000] GICv3: Pseudo-NMIs enabled using forced ICC_PMR_EL1 synchronisationUnrelated, but you seem to be running with ICC_CTLR_EL3.PMHE set, which makes the overhead of pseudo-NMIs much higher than it should be (you take a DSB SY on each interrupt unmasking). If you are not using 1:N distribution of SPIs on the secure side, consider turning that off in your firmware. This should make NMIs slightly more pleasant to use.
Thanks for the hint. I speak to the BIOS guys. John _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel