From: Paolo Bonzini <pbonzini@redhat.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gleb Natapov <gleb@kernel.org>, KVM <kvm@vger.kernel.org>,
linux-s390 <linux-s390@vger.kernel.org>,
Cornelia Huck <cornelia.huck@de.ibm.com>,
Michael Mueller <mimu@linux.vnet.ibm.com>
Subject: Re: [PATCH 0/3] Improved yield performance
Date: Wed, 26 Feb 2014 16:16:00 +0100 [thread overview]
Message-ID: <530E0530.3060809@redhat.com> (raw)
In-Reply-To: <1393427659-42501-1-git-send-email-borntraeger@de.ibm.com>
Il 26/02/2014 16:14, Christian Borntraeger ha scritto:
> Paolo,
>
> here is the reworked yield heuristics series against kvm/queue with
> your suggested changes.
>
> Attached is a minimized testcase that reproduces the performance
> win (runtime 0:50 instead of 1:00). The constants and the setup
> seem a bit artificial but these seem to reproduce the problem on my
> test system: as soon as there is contention from other guests the
> patch improves the runtime of belows testcase. The original test
> had 8 competing guests with 4 cpus, I simplified that a bit to have
> one big guest as cpu stealer.
>
> host 20 cpus
> GUEST1 (20vCPUS) GUEST2(40vCPUS)
> runs the test all 40 CPUs cpu bound
>
>
> The testcase stresses the IPC system call, since that creates a lot
> of diag44 exits on s390 if contended.
>
> Some other spinlock tests like fio on guest tmpfs seem to be unaffected.
>
> Please consider for kvm/queue. If you have some performance tests
> a regression run on x86 is welcome.
Yes, will apply as soon as kvm/queue moves to kvm/next (1 hour or so).
Paolo
prev parent reply other threads:[~2014-02-26 15:16 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-26 15:14 [PATCH 0/3] Improved yield performance Christian Borntraeger
2014-02-26 15:14 ` [PATCH 1/3] KVM: s390: implementation of kvm_arch_vcpu_runnable() Christian Borntraeger
2014-02-26 15:14 ` [PATCH 2/3] KVM: add kvm_arch_vcpu_runnable() test to kvm_vcpu_on_spin() loop Christian Borntraeger
2014-02-27 18:11 ` Raghavendra KT
2014-02-27 18:20 ` Paolo Bonzini
2014-02-26 15:14 ` [PATCH 3/3] KVM/s390: Set preempted flag during vcpu wakeup and interrupt delivery Christian Borntraeger
2014-02-26 15:16 ` Paolo Bonzini [this message]
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