mirror of https://github.com/torvalds/linux.git
593377036e
As of today, KVM notes a quiescent state only in guest entry, which is good as it avoids the guest being interrupted for current RCU operations. While the guest vcpu runs, it can be interrupted by a timer IRQ that will check for any RCU operations waiting for this CPU. In case there are any of such, it invokes rcu_core() in order to sched-out the current thread and note a quiescent state. This occasional schedule work will introduce tens of microsseconds of latency, which is really bad for vcpus running latency-sensitive applications, such as real-time workloads. So, note a quiescent state in guest exit, so the interrupted guests is able to deal with any pending RCU operations before being required to invoke rcu_core(), and thus avoid the overhead of related scheduler work. Signed-off-by: Leonardo Bras <leobras@redhat.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240511020557.1198200-1-leobras@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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| asm-generic | ||
| clocksource | ||
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| drm | ||
| dt-bindings | ||
| keys | ||
| kunit | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
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| misc | ||
| net | ||
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| ras | ||
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| rv | ||
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| target | ||
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| uapi | ||
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