From: Paolo Bonzini <pbonzini@redhat.com>
To: cauchy-love <cauchy-love@163.com>, Stefan Hajnoczi <stefanha@gmail.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] Greate difference of disk I/O performance for guest on Qemu-2.30 of CentOS.
Date: Fri, 19 Jun 2015 10:37:23 +0200 [thread overview]
Message-ID: <5583D4C3.5060409@redhat.com> (raw)
In-Reply-To: <79b03cb4.2428.14e0957997f.Coremail.cauchy-love@163.com>
On 19/06/2015 03:03, cauchy-love wrote:
> I have tried your qemu cammand line but got no luck (the embedded os
> have no virtio support but this is not the problem i think). The
> problem probably lies in the host kernel version as it is the only
> difference for my tests. I traced the guest kernel and found the ATA
> drivers always used non-DMA mode (CentOS 7 and CentOS 6.5 are the
> same at this point).
You can use perf to see what's the difference.
Perhaps CentOS 6.5 used ext4 and 7 uses XFS? Though in general XFS is
the faster one...
Paolo
next prev parent reply other threads:[~2015-06-19 8:37 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-15 13:14 [Qemu-devel] Greate difference of disk I/O performance for guest on Qemu-2.30 of CentOS cauchy-love
2015-06-16 13:05 ` Stefan Hajnoczi
2015-06-19 0:40 ` cauchy-love
2015-06-19 15:24 ` Stefan Hajnoczi
2015-06-19 1:03 ` cauchy-love
2015-06-19 8:37 ` Paolo Bonzini [this message]
2015-06-23 3:22 ` cauchy-love
[not found] ` <5ec70e6c.267de.14e257e00ab.Coremail.cauchy-love@163.com>
[not found] ` <558AA072.3080507@redhat.com>
2015-06-24 12:31 ` cauchy-love
2015-06-24 12:32 ` Paolo Bonzini
2015-06-24 12:50 ` cauchy-love
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