From: Sean Christopherson <seanjc@google.com>
To: Yosry Ahmed <yosry@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Marc Zyngier <maz@kernel.org>, Oliver Upton <oupton@kernel.org>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Janosch Frank <frankja@linux.ibm.com>,
Claudio Imbrenda <imbrenda@linux.ibm.com>,
Joey Gouly <joey.gouly@arm.com>,
Steffen Eiden <seiden@linux.ibm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
David Hildenbrand <david@kernel.org>,
kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 00/12] KVM: selftests: Add more syscall wrappers, fix hardware_disable_test
Date: Fri, 31 Jul 2026 14:41:37 -0700 [thread overview]
Message-ID: <am0Wkak_vhy1n_xu@google.com> (raw)
In-Reply-To: <CAO9r8zO-eCz-4Gpa_FUjRKPaDj82PP7et7KON4S5QfhRU2J-Ug@mail.gmail.com>
On Fri, Jul 31, 2026, Yosry Ahmed wrote:
> On Fri, Jul 31, 2026 at 12:56 PM Sean Christopherson <seanjc@google.com> wrote:
> >
> > Third time's a charm. Sorry for the spam.
> >
> > Buried in the middle of this is a fix for the hardware_disable_test where
> > it can end up with a runtime of multiple minutes when running a preemptible
> > kernels on a large NUMA system. Turns out my analysis/guess in v1 was wrong;
> > the problem isn't direct CPU contention, it's that letting the workers do any
> > amount of "real" work on any CPUs leads to pthread_create() slowdowns from
> > the perspective of the caller.
>
> How long does the test take to run with this series?
Less than 5 seconds if nothing else is running. ~12 seconds if I run it
concurrently with mmu_stress_test using default settings, and ~25 seconds if I
run it on an overloaded system (naively running all selftests in parallel).
next prev parent reply other threads:[~2026-07-31 21:41 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-31 19:56 [PATCH v3 00/12] KVM: selftests: Add more syscall wrappers, fix hardware_disable_test Sean Christopherson
2026-07-31 19:56 ` [PATCH v3 01/12] KVM: selftests: Add a KVM syscall wrapper for sched_setaffinity() Sean Christopherson
2026-07-31 19:56 ` [PATCH v3 02/12] KVM: selftests: Set threads CPU affinity before doing work in hardware disable test Sean Christopherson
2026-07-31 19:56 ` [PATCH v3 03/12] KVM: selftests: Pre-set threads affinity in hardware disable test when possible Sean Christopherson
2026-07-31 19:56 ` [PATCH v3 04/12] KVM: selftests: Return the target CPU from pin_task_to_random_cpu() Sean Christopherson
2026-07-31 19:56 ` [PATCH v3 05/12] KVM: selftests: Extract picking of random CPU from cpu_set_t to separate API Sean Christopherson
2026-07-31 19:56 ` [PATCH v3 06/12] KVM: selftests: Affine threads to random CPUs in hardware disable test Sean Christopherson
2026-07-31 19:56 ` [PATCH v3 07/12] KVM: selftests: Drop unreachable, dead code from " Sean Christopherson
2026-07-31 19:56 ` [PATCH v3 08/12] KVM: selftests: Add KVM syscall wrapper for pthread_create() Sean Christopherson
2026-07-31 19:56 ` [PATCH v3 09/12] KVM: selftests: Add KVM syscall wrappers for pthread_{cancel,join}() Sean Christopherson
2026-07-31 19:56 ` [PATCH v3 10/12] KVM: selftests: Add helper APIs to cancel+join pthreads Sean Christopherson
2026-07-31 19:56 ` [PATCH v3 11/12] KVM: selftests: Add KVM syscall wrappers for pthread_{g,s}etaffinity_np() Sean Christopherson
2026-07-31 19:56 ` [PATCH v3 12/12] KVM: selftests: Clean up global constants in hardware disable test Sean Christopherson
2026-07-31 21:35 ` [PATCH v3 00/12] KVM: selftests: Add more syscall wrappers, fix hardware_disable_test Yosry Ahmed
2026-07-31 21:41 ` Sean Christopherson [this message]
2026-07-31 21:43 ` Yosry Ahmed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=am0Wkak_vhy1n_xu@google.com \
--to=seanjc@google.com \
--cc=borntraeger@linux.ibm.com \
--cc=david@kernel.org \
--cc=frankja@linux.ibm.com \
--cc=imbrenda@linux.ibm.com \
--cc=joey.gouly@arm.com \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.linux.dev \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=oupton@kernel.org \
--cc=pbonzini@redhat.com \
--cc=seiden@linux.ibm.com \
--cc=suzuki.poulose@arm.com \
--cc=yosry@kernel.org \
--cc=yuzenghui@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).