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| author | Rik van Riel <riel@redhat.com> | 2012-06-19 16:51:04 -0400 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2012-07-06 14:11:18 -0300 |
| commit | 5cfc2aabcb282f4554e7086c9893b386ad6ba9d4 (patch) | |
| tree | 81b9989c069f54e42a748c8af6a2989bdbe6a8b9 /virt | |
| parent | 21b26c08535c992802402c7ba2d789ca9e1a5707 (diff) | |
| download | lwn-5cfc2aabcb282f4554e7086c9893b386ad6ba9d4.tar.gz lwn-5cfc2aabcb282f4554e7086c9893b386ad6ba9d4.zip | |
KVM: handle last_boosted_vcpu = 0 case
If last_boosted_vcpu == 0, then we fall through all test cases and
may end up with all VCPUs pouncing on vcpu 0. With a large enough
guest, this can result in enormous runqueue lock contention, which
can prevent vcpu0 from running, leading to a livelock.
Changing < to <= makes sure we properly handle that case.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 636bd08bb399..b3ce91c623e2 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1598,7 +1598,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me) */ for (pass = 0; pass < 2 && !yielded; pass++) { kvm_for_each_vcpu(i, vcpu, kvm) { - if (!pass && i < last_boosted_vcpu) { + if (!pass && i <= last_boosted_vcpu) { i = last_boosted_vcpu; continue; } else if (pass && i > last_boosted_vcpu) |