From: Marcelo Tosatti <mtosatti@redhat.com>
To: "Li, Liang Z" <liang.z.li@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] about the patch kvmclock Ensure proper env->tsc value for kvmclock_current_nsec calculation
Date: Thu, 13 Aug 2015 19:16:50 -0300 [thread overview]
Message-ID: <20150813221650.GA8109@amt.cnet> (raw)
In-Reply-To: <F2CBF3009FA73547804AE4C663CAB28E5B49A2@shsmsx102.ccr.corp.intel.com>
On Thu, Aug 13, 2015 at 01:25:29AM +0000, Li, Liang Z wrote:
> Hi Paolo & Marcelo,
>
> Could please point out what issue the patch 317b0a6d8ba44e try to fix? I found in live migration the cpu_synchronize_all_states will be called twice, and it will take more than 1 ms sometimes. I try to do some optimization but lack the knowledge about the background.
What the code in 317b0a6d8ba44e requires is to retrieve the TSC value
from the kernel.
Perhaps you can trace kvm_arch_get_regs and look why its taking that
amount of time and what can be done to improve it.
next prev parent reply other threads:[~2015-08-13 22:17 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-13 1:25 [Qemu-devel] about the patch kvmclock Ensure proper env->tsc value for kvmclock_current_nsec calculation Li, Liang Z
2015-08-13 22:16 ` Marcelo Tosatti [this message]
2015-08-14 1:23 ` Li, Liang Z
2015-08-14 7:31 ` Marcin Gibuła
2015-08-14 7:51 ` Li, Liang Z
2015-08-14 8:51 ` Marcin Gibuła
2015-08-14 9:18 ` Li, Liang Z
2015-08-14 14:10 ` Marcin Gibuła
2015-08-14 22:35 ` Marcelo Tosatti
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