From: Mathieu Desnoyers <mathieu.desnoyers@efficios•com>
To: Sean Christopherson <seanjc@google•com>
Cc: KVM list <kvm@vger•kernel.org>,
Peter Zijlstra <peterz@infradead•org>,
Catalin Marinas <catalin.marinas@arm•com>,
linux-kernel <linux-kernel@vger•kernel.org>,
Will Deacon <will@kernel•org>, Guo Ren <guoren@kernel•org>,
linux-kselftest <linux-kselftest@vger•kernel.org>,
Ben Gardon <bgardon@google•com>, shuah <shuah@kernel•org>,
Paul Mackerras <paulus@samba•org>,
linux-s390 <linux-s390@vger•kernel.org>, gor <gor@linux•ibm.com>,
"Russell King, ARM Linux" <linux@armlinux•org.uk>,
linux-csky <linux-csky@vger•kernel.org>,
Christian Borntraeger <borntraeger@de•ibm.com>,
Ingo Molnar <mingo@redhat•com>, dvhart <dvhart@infradead•org>,
linux-mips <linux-mips@vger•kernel.org>,
Boqun Feng <boqun.feng@gmail•com>, paulmck <paulmck@kernel•org>,
Heiko Carstens <hca@linux•ibm.com>, rostedt <rostedt@goodmis•org>,
Shakeel Butt <shakeelb@google•com>,
Andy Lutomirski <luto@kernel•org>,
Thomas Gleixner <tglx@linutronix•de>,
Peter Foley <pefoley@google•com>,
linux-arm-kernel <linux-arm-kernel@lists•infradead.org>,
Thomas Bogendoerfer <tsbogend@alpha•franken.de>,
Oleg Nesterov <oleg@redhat•com>,
Paolo Bonzini <pbonzini@redhat•com>,
linuxppc-dev <linuxppc-dev@lists•ozlabs.org>
Subject: Re: [PATCH v2 4/5] KVM: selftests: Add a test for KVM_RUN+rseq to detect task migration bugs
Date: Fri, 27 Aug 2021 20:06:20 -0400 (EDT) [thread overview]
Message-ID: <1054916754.30218.1630109180443.JavaMail.zimbra@efficios.com> (raw)
In-Reply-To: <YSlz8h9SWgeuicak@google.com>
----- On Aug 27, 2021, at 7:23 PM, Sean Christopherson seanjc@google•com wrote:
> On Fri, Aug 27, 2021, Mathieu Desnoyers wrote:
[...]
>> Does it reproduce if we randomize the delay to have it picked randomly from 0us
>> to 100us (with 1us step) ? It would remove a lot of the needs for arch-specific
>> magic delay value.
>
> My less-than-scientific testing shows that it can reproduce at delays up to
> ~500us,
> but above ~10us the reproducibility starts to drop. The bug still reproduces
> reliably, it just takes more iterations, and obviously the test runs a bit
> slower.
>
> Any objection to using a 1-10us delay, e.g. a simple usleep((i % 10) + 1)?
Works for me, thanks!
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
next prev parent reply other threads:[~2021-08-28 0:07 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-20 22:49 [PATCH v2 0/5] KVM: rseq: Fix and a test for a KVM+rseq bug Sean Christopherson
2021-08-20 22:49 ` [PATCH v2 1/5] KVM: rseq: Update rseq when processing NOTIFY_RESUME on xfer to KVM guest Sean Christopherson
2021-08-23 15:00 ` Mathieu Desnoyers
2021-08-20 22:49 ` [PATCH v2 2/5] entry: rseq: Call rseq_handle_notify_resume() in tracehook_notify_resume() Sean Christopherson
2021-08-20 22:50 ` [PATCH v2 3/5] tools: Move x86 syscall number fallbacks to .../uapi/ Sean Christopherson
2021-08-20 22:50 ` [PATCH v2 4/5] KVM: selftests: Add a test for KVM_RUN+rseq to detect task migration bugs Sean Christopherson
2021-08-23 15:18 ` Mathieu Desnoyers
2021-08-23 15:20 ` Mathieu Desnoyers
2021-08-26 0:51 ` Sean Christopherson
2021-08-26 18:42 ` Mathieu Desnoyers
2021-08-26 23:54 ` Sean Christopherson
2021-08-27 19:09 ` Mathieu Desnoyers
2021-08-27 23:23 ` Sean Christopherson
2021-08-28 0:06 ` Mathieu Desnoyers [this message]
2021-08-20 22:50 ` [PATCH v2 5/5] KVM: selftests: Remove __NR_userfaultfd syscall fallback Sean Christopherson
2021-08-23 23:46 ` Ben Gardon
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=1054916754.30218.1630109180443.JavaMail.zimbra@efficios.com \
--to=mathieu.desnoyers@efficios$(echo .)com \
--cc=bgardon@google$(echo .)com \
--cc=boqun.feng@gmail$(echo .)com \
--cc=borntraeger@de$(echo .)ibm.com \
--cc=catalin.marinas@arm$(echo .)com \
--cc=dvhart@infradead$(echo .)org \
--cc=gor@linux$(echo .)ibm.com \
--cc=guoren@kernel$(echo .)org \
--cc=hca@linux$(echo .)ibm.com \
--cc=kvm@vger$(echo .)kernel.org \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
--cc=linux-csky@vger$(echo .)kernel.org \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=linux-kselftest@vger$(echo .)kernel.org \
--cc=linux-mips@vger$(echo .)kernel.org \
--cc=linux-s390@vger$(echo .)kernel.org \
--cc=linux@armlinux$(echo .)org.uk \
--cc=linuxppc-dev@lists$(echo .)ozlabs.org \
--cc=luto@kernel$(echo .)org \
--cc=mingo@redhat$(echo .)com \
--cc=oleg@redhat$(echo .)com \
--cc=paulmck@kernel$(echo .)org \
--cc=paulus@samba$(echo .)org \
--cc=pbonzini@redhat$(echo .)com \
--cc=pefoley@google$(echo .)com \
--cc=peterz@infradead$(echo .)org \
--cc=rostedt@goodmis$(echo .)org \
--cc=seanjc@google$(echo .)com \
--cc=shakeelb@google$(echo .)com \
--cc=shuah@kernel$(echo .)org \
--cc=tglx@linutronix$(echo .)de \
--cc=tsbogend@alpha$(echo .)franken.de \
--cc=will@kernel$(echo .)org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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