On Fri, Oct 23, 2009 at 02:05:32PM +0100, Daniel P. Berrange wrote:
A number of driver API methods which acquire the driver mutex only ever used the driver object in a read-only fashion. All these uses are converted to call qemuDriverLockRO() allowing for greater concurrency.
* src/qemu/qemu_conf.h: s/Mutex/RWLock/ * src/qemu/qemu_driver.c: Add a qemuDriverLockRO() method and use it anywhere that doesn't require a write lock on the driver
Hum, I still wonder about erro handling strategies there, for example even taking a read lock may fail not because of a programing error because there is already too many read lock taken. [...]
@@ -6834,6 +6846,8 @@ cleanup:
if (vm) virDomainObjUnlock(vm); + qemuDriverUnlock(driver); + qemuDriverLock(driver); if (event) qemuDomainEventQueue(driver, event); qemuDriverUnlock(driver);
Huh ??? really ? we need a way to allow other threads to get in ? Maybe a tiny wait here would allow a rescheduling especially if on a single processor. But otherwise this looks like a fairly automatic conversion so should go in with 02/21 when ready, ACK Daniel -- Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/ daniel@veillard.com | Rpmfind RPM search engine http://rpmfind.net/ http://veillard.com/ | virtualization library http://libvirt.org/