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| author | Jay Zhou <jianjay.zhou@huawei.com> | 2017-07-28 18:28:53 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-08-01 17:27:33 +0200 |
| commit | 1931076077254a2886daa7c830c7838ebd1f81ef (patch) | |
| tree | 79cd172b4130defaf256155b99b8950234336408 /io/dns-resolver.c | |
| parent | 8bfce83a3b50d45b7107a50a6cd61d5304a925a2 (diff) | |
migration: optimize the downtime
Qemu_savevm_state_cleanup takes about 300ms in my ram migration tests
with a 8U24G vm(20G is really occupied), the main cost comes from
KVM_SET_USER_MEMORY_REGION ioctl when mem.memory_size = 0 in
kvm_set_user_memory_region. In kmod, the main cost is
kvm_zap_obsolete_pages, which traverses the active_mmu_pages list to
zap the unsync sptes.
It can be optimized by delaying memory_global_dirty_log_stop to the next
vm_start.
Changes v2->v3:
- NULL VMChangeStateHandler if it is deleted and protect the scenario
of nested invocations of memory_global_dirty_log_start/stop [Paolo]
Changes v1->v2:
- create a VMChangeStateHandler in memory.c to reduce the coupling [Paolo]
Signed-off-by: Jay Zhou <jianjay.zhou@huawei.com>
Message-Id: <1501237733-2736-1-git-send-email-jianjay.zhou@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'io/dns-resolver.c')
0 files changed, 0 insertions, 0 deletions