From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34063) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZzR5D-00006r-4x for qemu-devel@nongnu.org; Thu, 19 Nov 2015 10:25:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZzR59-0001fo-WE for qemu-devel@nongnu.org; Thu, 19 Nov 2015 10:25:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46115) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZzR59-0001fi-Re for qemu-devel@nongnu.org; Thu, 19 Nov 2015 10:25:07 -0500 References: <1447945814-15765-1-git-send-email-mjrosato@linux.vnet.ibm.com> <1447945814-15765-3-git-send-email-mjrosato@linux.vnet.ibm.com> From: Paolo Bonzini Message-ID: <564DE9CE.6080303@redhat.com> Date: Thu, 19 Nov 2015 16:25:02 +0100 MIME-Version: 1.0 In-Reply-To: <1447945814-15765-3-git-send-email-mjrosato@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 2/9] cpus: Add a sync version of cpu_remove() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Matthew Rosato , qemu-devel@nongnu.org Cc: agraf@suse.de, borntraeger@de.ibm.com, Bharata B Rao , cornelia.huck@de.ibm.com, afaerber@suse.de, rth@twiddle.net On 19/11/2015 16:10, Matthew Rosato wrote: > From: Bharata B Rao > > This sync API will be used by the CPU hotplug code to wait for the CPU to > completely get removed before flagging the failure to the device_add > command. > > Sync version of this call is needed to correctly recover from CPU > realization failures when ->plug() handler fails. > > Signed-off-by: Bharata B Rao > Signed-off-by: Matthew Rosato > [Call cpu_remove() directly from cpu_remove_sync()] Are you using it in these patches? Paolo > --- > cpus.c | 12 ++++++++++++ > include/qom/cpu.h | 8 ++++++++ > 2 files changed, 20 insertions(+) > > diff --git a/cpus.c b/cpus.c > index af2b274..c2444ba 100644 > --- a/cpus.c > +++ b/cpus.c > @@ -1070,6 +1070,8 @@ static void *qemu_kvm_cpu_thread_fn(void *arg) > qemu_kvm_wait_io_event(cpu); > if (cpu->exit && !cpu_can_run(cpu)) { > qemu_kvm_destroy_vcpu(cpu); > + cpu->created = false; > + qemu_cond_signal(&qemu_cpu_cond); > qemu_mutex_unlock(&qemu_global_mutex); > return NULL; > } > @@ -1174,6 +1176,8 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) > } > if (remove_cpu) { > qemu_tcg_destroy_vcpu(remove_cpu); > + cpu->created = false; > + qemu_cond_signal(&qemu_cpu_cond); > remove_cpu = NULL; > } > } > @@ -1339,6 +1343,14 @@ void cpu_remove(CPUState *cpu) > qemu_cpu_kick(cpu); > } > > +void cpu_remove_sync(CPUState *cpu) > +{ > + cpu_remove(cpu); > + while (cpu->created) { > + qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex); > + } > +} > + > /* For temporary buffers for forming a name */ > #define VCPU_THREAD_NAME_SIZE 16 > > diff --git a/include/qom/cpu.h b/include/qom/cpu.h > index 6a1d887..dc2b566 100644 > --- a/include/qom/cpu.h > +++ b/include/qom/cpu.h > @@ -705,6 +705,14 @@ void cpu_resume(CPUState *cpu); > */ > void cpu_remove(CPUState *cpu); > > + /** > + * cpu_remove_sync: > + * @cpu: The CPU to remove. > + * > + * Requests the CPU to be removed and waits till it is removed. > + */ > +void cpu_remove_sync(CPUState *cpu); > + > /** > * qemu_init_vcpu: > * @cpu: The vCPU to initialize. >