From: Gleb Natapov <gleb@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>,
Marcelo Tosatti <mtosatti@redhat.com>, kvm <kvm@vger.kernel.org>
Subject: Re: [PATCH] KVM: VMX: Do not overwrite vcpu->srcu_idx in vmx_vcpu_reset
Date: Thu, 14 Mar 2013 17:11:06 +0200 [thread overview]
Message-ID: <20130314151106.GA15717@redhat.com> (raw)
In-Reply-To: <5141E7FA.8060003@redhat.com>
On Thu, Mar 14, 2013 at 04:08:42PM +0100, Paolo Bonzini wrote:
> Il 14/03/2013 16:03, Jan Kiszka ha scritto:
> >> > vcpu->srcu_idx = srcu_read_lock()
> >> > idx = srcu_read_lock(&vcpu->kvm->srcu);
> >> > srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
> >> > vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
> >> > srcu_read_unlock(&vcpu->kvm->srcu, idx);
> >> > srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
> >> >
> >> > Not sure this is valid.
> > Grmbl, likely not.
>
> It might be.
>
> Isn't it the same as two different CPUs doing
>
> CPU 1 CPU 2
> ------------------------------------------------------------------------------------------------
>
> vcpu->srcu_idx = srcu_read_lock()
> idx = srcu_read_lock(&vcpu->kvm->srcu);
> srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
> vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
> srcu_read_unlock(&vcpu->kvm->srcu, idx);
> srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
>
> ?
>
Srcu may have per cpu state. We can always ask Paul.
--
Gleb.
next prev parent reply other threads:[~2013-03-14 15:11 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-14 14:52 [PATCH] KVM: VMX: Do not overwrite vcpu->srcu_idx in vmx_vcpu_reset Jan Kiszka
2013-03-14 15:00 ` Gleb Natapov
2013-03-14 15:03 ` Jan Kiszka
2013-03-14 15:08 ` Paolo Bonzini
2013-03-14 15:11 ` Gleb Natapov [this message]
2013-03-14 15:45 ` Paolo Bonzini
2013-03-14 15:11 ` Jan Kiszka
2013-03-14 19:14 ` Marcelo Tosatti
2013-03-14 19:20 ` Jan Kiszka
2013-03-14 19:39 ` [PATCH v2] " Jan Kiszka
2013-03-15 7:09 ` Jan Kiszka
2013-03-14 20:02 ` [PATCH] " Marcelo Tosatti
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