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| author | Wanpeng Li <[email protected]> | 2018-02-13 09:05:41 +0800 |
|---|---|---|
| committer | Radim Krčmář <[email protected]> | 2018-03-06 18:40:45 +0100 |
| commit | b2798ba0b8769b42f00899b44a538b5fcecb480d (patch) | |
| tree | d62c2b5aadf73a3f60523e8cd65444c7605c3808 /tools/perf/scripts/python/syscall-counts-by-pid.py | |
| parent | a4429e53c9b3082b05e51224c3d58dbdd39306c5 (diff) | |
KVM: X86: Choose qspinlock when dedicated physical CPUs are available
Waiman Long mentioned that:
> Generally speaking, unfair lock performs well for VMs with a small
> number of vCPUs. Native qspinlock may perform better than pvqspinlock
> if there is vCPU pinning and there is no vCPU over-commitment.
This patch uses the KVM_HINTS_DEDICATED performance hint, which is
provided by the hypervisor admin, to choose the qspinlock algorithm
when a dedicated physical CPU is available.
PV_DEDICATED = 1, PV_UNHALT = anything: default is qspinlock
PV_DEDICATED = 0, PV_UNHALT = 1: default is Hybrid PV queued/unfair lock
PV_DEDICATED = 0, PV_UNHALT = 0: default is tas
Cc: Paolo Bonzini <[email protected]>
Cc: Radim Krčmář <[email protected]>
Cc: Eduardo Habkost <[email protected]>
Signed-off-by: Wanpeng Li <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
Signed-off-by: Radim Krčmář <[email protected]>
Diffstat (limited to 'tools/perf/scripts/python/syscall-counts-by-pid.py')
0 files changed, 0 insertions, 0 deletions