Re: [libvirt] [PATCH] qemu: Adjust VM id allocation

On Tue, Jul 28, 2015 at 05:41:25PM +0200, Erik Skultety wrote: > Our atomic increment (virAtomicIntInc) uses (if available) gcc > __sync_add_and_fetch builtin. In qemu driver though, we'd profit more > from __sync_fetch_and_add builtin. To keep it simplistic, this patch > adjusts qemu driver initialization rather than adding a new atomic > increment macro. > --- > src/qemu/qemu_conf.c | 2 +- > src/qemu/qemu_conf.h | 2 +- > src/qemu/qemu_driver.c | 7 ++----- > 3 files changed, 4 insertions(+), 7 deletions(-) > > diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c > index 38d4a86..29049dc 100644 > --- a/src/qemu/qemu_conf.c > +++ b/src/qemu/qemu_conf.c > @@ -1492,7 +1492,7 @@ qemuSetUnprivSGIO(virDomainDeviceDefPtr dev) > > int qemuDriverAllocateID(virQEMUDriverPtr driver) > { > - return virAtomicIntInc(&driver->nextvmid); > + return virAtomicIntInc(&driver->lastvmid); > } > > > diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h > index 3f73929..ed9cd46 100644 > --- a/src/qemu/qemu_conf.h > +++ b/src/qemu/qemu_conf.h > @@ -192,7 +192,7 @@ struct _virQEMUDriver { > virThreadPoolPtr workerPool; > > /* Atomic increment only */ > - int nextvmid; > + int lastvmid; > > /* Atomic inc/dec only */ > unsigned int nactive; > diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c > index a761448..055f0ca 100644 > --- a/src/qemu/qemu_driver.c > +++ b/src/qemu/qemu_driver.c > @@ -612,7 +612,7 @@ qemuDomainFindMaxID(virDomainObjPtr vm, > int *driver_maxid = data; > > if (vm->def->id >= *driver_maxid) You can s/>=/>/ now too - functionally the same but slightly less misleading > - *driver_maxid = vm->def->id + 1; > + *driver_maxid = vm->def->id; > > return 0; > } > @@ -649,9 +649,6 @@ qemuStateInitialize(bool privileged, > qemu_driver->inhibitCallback = callback; > qemu_driver->inhibitOpaque = opaque; > > - /* Don't have a dom0 so start from 1 */ > - qemu_driver->nextvmid = 1; > - > qemu_driver->privileged = privileged; > > if (!(qemu_driver->domains = virDomainObjListNew())) > @@ -909,7 +906,7 @@ qemuStateInitialize(bool privileged, > * threads */ > virDomainObjListForEach(qemu_driver->domains, > qemuDomainFindMaxID, > - &qemu_driver->nextvmid); > + &qemu_driver->lastvmid); > > virDomainObjListForEach(qemu_driver->domains, > qemuDomainNetsRestart, ACK Regards, Daniel