Re: [PATCH v2 2/2] x86/hyperv: remove on-stack cpumask from hv_send_ipi_mask_allbutself
From: Thomas Gleixner <hidden>
Date: 2021-09-26 22:03:15
Also in:
lkml
Wei! On Fri, Sep 10 2021 at 18:57, Wei Liu wrote:
quoted hunk ↗ jump to hunk
-static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector) +static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector, + bool exclude_self) { struct hv_send_ipi_ex **arg; struct hv_send_ipi_ex *ipi_arg;@@ -123,7 +124,10 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector) if (!cpumask_equal(mask, cpu_present_mask)) {
Not part of that patch, but is checking cpu_present_mask correct here? If so then this really lacks a comment for the casual reader.
ipi_arg->vp_set.format = HV_GENERIC_SET_SPARSE_4K; - nr_bank = cpumask_to_vpset(&(ipi_arg->vp_set), mask); + if (exclude_self) + nr_bank = cpumask_to_vpset_noself(&(ipi_arg->vp_set), mask); + else + nr_bank = cpumask_to_vpset(&(ipi_arg->vp_set), mask); }
But, what happens in the case that mask == cpu_present_mask and
exclude_self == true?
AFAICT it ends up sending the IPI to all CPUs including self:
if (!nr_bank)
ipi_arg->vp_set.format = HV_GENERIC_SET_ALL;
Not entirely correct, right?
Thanks,
tglx