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From: Liang Li <liang.z.li@intel.com>
To: qemu-devel@nongnu.org
Cc: Liang Li <liang.z.li@intel.com>,
	ehabkost@redhat.com, mst@redhat.com, mtosatti@redhat.com,
	quintela@redhat.com, m.gibula@beyond.pl, amit.shah@redhat.com,
	pbonzini@redhat.com, rth@twiddle.net
Subject: [Qemu-devel] [v2 0/2] Optimize the env->tsc update operation
Date: Thu,  5 Nov 2015 11:51:02 +0800	[thread overview]
Message-ID: <1446695464-27116-1-git-send-email-liang.z.li@intel.com> (raw)

This patch set aims for reducing the live migration downtime. It
updates the env->tsc when stopping kvmclock with a new function.
Rather than using 'cpu_synchronize_all_states()', which updates the
whole CPU context just for updating the env->tsc.

For a VM with 4 CPUs, this patch set can help to reduce the VM downtime
about 100us.

Changes in v2:
  * Simplify 'kvm_get_tsc()' function.
  * Introduce a new function 'kvm_synchronize_all_tsc()'

Liang Li (2):
  kvmclock: add a new function to update env->tsc.
  Revert "Introduce cpu_clean_all_dirty"

 cpus.c                 |  9 ---------
 hw/i386/kvm/clock.c    | 18 ++----------------
 include/sysemu/cpus.h  |  1 -
 include/sysemu/kvm.h   |  8 --------
 kvm-all.c              |  5 -----
 target-i386/kvm.c      | 45 +++++++++++++++++++++++++++++++++++++++++++++
 target-i386/kvm_i386.h |  1 +
 7 files changed, 48 insertions(+), 39 deletions(-)

-- 
1.9.1

             reply	other threads:[~2015-11-05  3:56 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-05  3:51 Liang Li [this message]
2015-11-05  3:51 ` [Qemu-devel] [v2 1/2] kvmclock: add a new function to update env->tsc Liang Li
2015-11-05  3:51 ` [Qemu-devel] [v2 2/2] Revert "Introduce cpu_clean_all_dirty" Liang Li
2015-11-05 10:28 ` [Qemu-devel] [v2 0/2] Optimize the env->tsc update operation Paolo Bonzini

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