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Subject: Re: [PATCH v2] kvm: Replace vcpu->swait with rcuwait
To:     Marc Zyngier <maz@kernel.org>, Davidlohr Bueso <dave@stgolabs.net>
Cc:     tglx@linutronix.de, kvm@vger.kernel.org,
        Davidlohr Bueso <dbueso@suse.de>, peterz@infradead.org,
        torvalds@linux-foundation.org, bigeasy@linutronix.de,
        linux-kernel@vger.kernel.org, rostedt@goodmis.org,
        linux-mips@vger.kernel.org, Paul Mackerras <paulus@ozlabs.org>,
        joel@joelfernandes.org, will@kernel.org,
        kvmarm@lists.cs.columbia.edu
References: <20200324044453.15733-1-dave@stgolabs.net>
 <20200324044453.15733-4-dave@stgolabs.net>
 <20200420164132.tjzk5ebx35m66yce@linux-p48b>
 <418acdb5001a9ae836095b7187338085@misterjones.org>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <22800f1b-3bdb-15b4-7592-93a7b244b45a@redhat.com>
Date:   Mon, 20 Apr 2020 19:25:28 +0200
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On 20/04/20 19:12, Marc Zyngier wrote:
>>
>>
>> -??? trace_kvm_vcpu_wakeup(block_ns, waited, vcpu_valid_wakeup(vcpu));
>> +??? trace_kvm_vcpu_wakeup(block_ns, !block_check,
>> vcpu_valid_wakeup(vcpu));
> 
> This looks like a change in the semantics of the tracepoint. Before
> this change, 'waited' would have been true if the vcpu waited at all.
> Here, you'd have false if it has been interrupted by a signal, even
> if the vcpu has waited for a period of time.
True, good catch.  Perhaps add macros prepare_to_rcuwait and
finish_rcuwait?

Paolo