Re: [PATCH 0/2] perf jevents: Add IOMMU PTW & device entry metrics

[Lefkowitz, Jacob]

On 10/29/26 16:12, Ian Rogers wrote:
>On Thu, Oct 29, 2026 at 12:06 PM Jacob Lefkowitz via B4 Relay
< >devnull+jlefkowi.akamai.com@xxxxxxxxxx> wrote:
>> They have been tested with a benchmark C program that
>> purposefully thrashed the TLB as well as with 'sleep 10'; both of
>> which work as expected.
>
>Cool, perhaps consider contributing them as test workloads:
>https://web.git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools next.git/tree/tools/perf/tests/workloads

Thanks for the suggestion! After reviewing the workload I wrote, I
realized it thrashes the CPU TLB rather than the IOMMU TLB, since it
doesn't perform any device-side DMA, so it doesn't actually exercise
these metrics in the way I thought it did.

For now, I will leave this series as is. Down the line I may write a workload that
thrashes the IOMMU TLB (likely implementing fio-like functionality in C) so perf
has a proper IOMMU workload; if I do, I'll send it as a separate patch.

Thanks,
Jacob