| Message ID | 1447945814-15765-3-git-send-email-mjrosato@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
On 19/11/2015 16:10, Matthew Rosato wrote: > From: Bharata B Rao <bharata@linux.vnet.ibm.com> > > 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 <bharata@linux.vnet.ibm.com> > Signed-off-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com> > [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. >
On 11/19/2015 10:25 AM, Paolo Bonzini wrote: > > > On 19/11/2015 16:10, Matthew Rosato wrote: >> From: Bharata B Rao <bharata@linux.vnet.ibm.com> >> >> 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 <bharata@linux.vnet.ibm.com> >> Signed-off-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com> >> [Call cpu_remove() directly from cpu_remove_sync()] > > Are you using it in these patches? > Ugh, nice catch -- I am not using it anymore, I decided it was fine to just use cpu_remove in patch 8 directly. So, this patch can be dropped from the set. Matt
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.