Re: [PATCH v10 0/3] Per-vCPU dirty quota-based throttling

Shivam Kumar
2024-03-21T06:10:44Z

> On 22-Feb-2024, at 1:22 AM, Shivam Kumar <shivam.kumar1@nutanix.com> wrote:
>
> The current v10 patchset includes the following changes over v9:
>
> 1. Use vma_pagesize as the dirty granularity for updating dirty quota
> on arm64.
> 2. Do not update dirty quota for instances where the hypervisor is
> writing into guest memory. Accounting for these instances in vCPUs'
> dirty quota is unfair to the vCPUs. Also, some of these instances,
> such as record_steal_time, frequently try to redundantly mark the same
> set of pages dirty again and again. To avoid these distortions, we had
> previously relied on checking the dirty bitmap to avoid redundantly
> updating quotas. Since we have now decoupled dirty-quota-based
> throttling from the live-migration dirty-tracking path, we have
> resolved this issue by simply avoiding the mis-accounting caused by
> these hypervisor-induced writes to guest memory. Through extensive
> experiments, we have verified that this new approach is approximately
> as effective as the prior approach that relied on checking the dirty
> bitmap.
>

Hi Marc,

I’ve tried my best to address all the concerns raised in the previous patchset. I’d really appreciate it if you could share your thoughts and any feedback you might have on this one.

Thanks,
Shivam