From: Avi Kivity <avi@redhat.com>
To: Lucas Meneghel Rodrigues <lmr@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
Sheng Yang <sheng@linux.intel.com>,
Joerg Roedel <joerg.roedel@amd.com>,
kvm@vger.kernel.org
Subject: Re: [PATCH 4/5] KVM: Lazify fpu activation and deactivation
Date: Thu, 14 Jan 2010 17:04:45 +0200 [thread overview]
Message-ID: <4B4F328D.6020103@redhat.com> (raw)
In-Reply-To: <1263479672.2300.5.camel@localhost.localdomain>
On 01/14/2010 04:34 PM, Lucas Meneghel Rodrigues wrote:
> On Thu, 2010-01-14 at 15:11 +0200, Avi Kivity wrote:
>
>>> Strangely, autotest only caught this on AMD and even it took a while.
>>> Lucas, can you integrate something like the following into autotest,
>>> so we exercise the preemption code harder?
>>>
> All right Avi, just added it to our TODO list, thanks!
>
On second thoughts, this will cause a severe performance loss (which may
also affect test results), due to cpu overcommit and excessive vcpu
migrations.
How about, instead:
Launch a background process with nthreads == ncpus, bind each thread to
a cpu, and execute a loop on each thread that sleeps for a random amount
of time from 1 to 10 milliseconds. This will exercise the preemption code.
In addition, every second or so, offline and online a random cpu. This
will cause tasks to be migrated and exercise the task migration code.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2010-01-14 15:04 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-30 16:25 [PATCH 0/5] Lazy fpu, cr0.ts Avi Kivity
2009-12-30 16:25 ` [PATCH 1/5] KVM: VMX: trace clts and lmsw instructions as cr accesses Avi Kivity
2009-12-30 16:25 ` [PATCH 2/5] KVM: Replace read accesses of vcpu->arch.cr0 by an accessor Avi Kivity
2009-12-30 16:25 ` [PATCH 3/5] KVM: VMX: Allow the guest to own some cr0 bits Avi Kivity
2009-12-30 16:25 ` [PATCH 4/5] KVM: Lazify fpu activation and deactivation Avi Kivity
2010-01-06 0:25 ` Marcelo Tosatti
2010-01-06 3:18 ` Avi Kivity
2010-01-06 6:21 ` Avi Kivity
2010-01-06 10:47 ` Joerg Roedel
2010-01-06 11:00 ` Avi Kivity
2010-01-14 13:11 ` Avi Kivity
2010-01-14 13:11 ` Avi Kivity
2010-01-14 14:34 ` Lucas Meneghel Rodrigues
2010-01-14 15:04 ` Avi Kivity [this message]
2009-12-30 16:25 ` [PATCH 5/5] KVM: VMX: Give the guest ownership of cr0.ts when the fpu is active Avi Kivity
2010-01-06 0:40 ` Marcelo Tosatti
2009-12-31 9:23 ` [PATCH 0/5] Lazy fpu, cr0.ts Sheng Yang
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