On Tue, Apr 20, 2021 at 10:37:39AM -0400, Peter Xu wrote: > On Tue, Apr 20, 2021 at 04:16:14AM -0400, Paolo Bonzini wrote: > > The main thread could start to send SIG_IPI at any time, even before signal > > blocked on vcpu thread. Therefore, start the vcpu thread with the signal > > blocked. > > > > Without this patch, on very busy cores the dirty_log_test could fail directly > > on receiving a SIGUSR1 without a handler (when vcpu runs far slower than main). > > > > Reported-by: Peter Xu <peterx@xxxxxxxxxx> > > Cc: stable@xxxxxxxxxxxxxxx > > Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> > > Yes, indeed better! :) > > Reviewed-by: Peter Xu <peterx@xxxxxxxxxx> I just remembered one thing: this will avoid program quits, but still we'll get the signal missing. From that pov I slightly prefer the old patch. However not a big deal so far as only dirty ring uses SIG_IPI, so there's always ring full which will just delay the kick. It's just we need to remember this when we extend IPI to non-dirty-ring tests as the kick is prone to be lost then. Thanks, -- Peter Xu
