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| author |   Liang Li <liang.z.li@intel.com> | 2015-12-08 09:14:07 +0800 |
|---|---|---|
| committer | Liang Li <liang.z.li@intel.com> | 2015-12-08 09:16:17 +0800 |
| commit | b52baab237a0b45cb18b26f529e6490b42574209 (patch) | |
| tree | e8bd69d1ccf45f46381617d27cfdd1966abde0b1 /kernel/drivers/s390/crypto/ap_bus.c | |
| parent | cc62f651747d5844cc12d33fb3620a7d05bae7dc (diff) | |
kvmclock: add a new function to update env->tsc.WW-2015-52
(Back port from upstream, commit id: 0fd7e098db30e302d27920487f0afec)
The commit 317b0a6d8 fixed an issue which caused by the outdated
env->tsc value, but the fix lead to 'cpu_synchronize_all_states()'
called twice during live migration. The 'cpu_synchronize_all_states()'
takes about 130us for a VM which has 4 vcpus, it's a bit expensive.
Synchronize the whole CPU context just for updating env->tsc is too
wasting, this patch use a new function to update the env->tsc.
Comparing to 'cpu_synchronize_all_states()', it only takes about 20us.
Change-Id: I7dc8371aa17b005d073249c3732d9a7424f20a25
Signed-off-by: Liang Li <liang.z.li@intel.com>
Message-Id: <1446695464-27116-2-git-send-email-liang.z.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'kernel/drivers/s390/crypto/ap_bus.c')
0 files changed, 0 insertions, 0 deletions