From: Paolo Bonzini <pbonzini@redhat.com>
To: Space Meyer <spm@google.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: kpsingh@kernel.org
Subject: Re: [PATCH] KVM: Deal with nested sleeps in kvm_vcpu_block()
Date: Wed, 30 Nov 2022 17:58:56 +0100 [thread overview]
Message-ID: <e43ffb47-6526-6b2d-f7b3-0755f3c54a71@redhat.com> (raw)
In-Reply-To: <20221130161946.3254953-1-spm@google.com>
On 11/30/22 17:19, Space Meyer wrote:
> bool kvm_vcpu_block(struct kvm_vcpu *vcpu)
> {
> + DEFINE_WAIT_FUNC(vcpu_block_wait, woken_wake_function);
> struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu);
> bool waited = false;
>
> @@ -3437,13 +3439,11 @@ bool kvm_vcpu_block(struct kvm_vcpu *vcpu)
> preempt_enable();
>
> for (;;) {
> - set_current_state(TASK_INTERRUPTIBLE);
> -
> if (kvm_vcpu_check_block(vcpu) < 0)
> break;
>
> waited = true;
> - schedule();
> + wait_woken(&vcpu_block_wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
> }
Also, this does not work I think, because there is
add_wait_queue()/remove_wait_queue() pair. Adding it is not easy
because KVM is using a struct rcuwait here instead of a wait_queue_t.
Paolo
next prev parent reply other threads:[~2022-11-30 17:04 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-30 16:19 Space Meyer
2022-11-30 16:48 ` Paolo Bonzini
2022-12-02 15:52 ` Space Meyer
2022-12-02 18:26 ` Paolo Bonzini
2022-11-30 16:58 ` Paolo Bonzini [this message]
2022-12-02 15:52 ` Space Meyer
2022-12-02 18:27 ` Paolo Bonzini
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