diff options
Diffstat (limited to 'src/plugin/mod.rs')
| -rw-r--r-- | src/plugin/mod.rs | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/src/plugin/mod.rs b/src/plugin/mod.rs index e62fd39..451ac66 100644 --- a/src/plugin/mod.rs +++ b/src/plugin/mod.rs @@ -479,16 +479,22 @@ pub fn run_vcpus( break; } - // Try to clear the signal that we use to kick VCPU if it is - // pending before attempting to handle pause requests. + // Only handle the pause request if kvm reported that it was + // interrupted by a signal. This helps to entire that KVM has had a chance + // to finish emulating any IO that may have immediately happened. + // If we eagerly check pre_run() then any IO that we + // just reported to the plugin won't have been processed yet by KVM. + // Not eagerly calling pre_run() also helps to reduce + // any overhead from checking if a pause request is pending. + // The assumption is that pause requests aren't common + // or frequent so it's better to optimize for the non-pause execution paths. if interrupted_by_signal { clear_signal(SIGRTMIN() + 0) .expect("failed to clear pending signal"); - } - - if let Err(e) = vcpu_plugin.pre_run(&vcpu) { - error!("failed to process pause on vcpu {}: {}", cpu_id, e); - break; + if let Err(e) = vcpu_plugin.pre_run(&vcpu) { + error!("failed to process pause on vcpu {}: {}", cpu_id, e); + break; + } } } } |