On 03/11/2010 11:42 AM, Daniel Veillard wrote:
On Thu, Mar 11, 2010 at 10:36:29AM -0500, Chris Lalancette wrote:
Currently if you dump the core of a qemu guest with qemudDomainCoreDump, subsequent commands will hang up libvirtd. This is because qemudDomainCoreDump uses qemuDomainWaitForMigrationComplete, which expects the qemuDriverLock to be held when it's called. This patch does the simple thing and moves the qemuDriveUnlock to the end of the qemudDomainCoreDump so that the driver lock is held for the entirety of the call (as it is done in qemudDomainSave). We will probably want to make the lock more fine-grained than that in the future, but we can fix both qemudDomainCoreDump and qemudDomainSave at the same time.
Signed-off-by: Chris Lalancette <clalance@redhat.com> --- src/qemu/qemu_driver.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index ee3dbd3..49983dd 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -4390,7 +4390,6 @@ static int qemudDomainCoreDump(virDomainPtr dom,
qemuDriverLock(driver); vm = virDomainFindByUUID(&driver->domains, dom->uuid); - qemuDriverUnlock(driver);
if (!vm) { char uuidstr[VIR_UUID_STRING_BUFLEN]; @@ -4401,7 +4400,7 @@ static int qemudDomainCoreDump(virDomainPtr dom, } priv = vm->privateData;
- if (qemuDomainObjBeginJob(vm) < 0) + if (qemuDomainObjBeginJobWithDriver(driver, vm) < 0) goto cleanup;
if (!virDomainObjIsActive(vm)) { @@ -4499,6 +4498,7 @@ cleanup: virDomainObjUnlock(vm); if (event) qemuDomainEventQueue(driver, event); + qemuDriverUnlock(driver); return ret; }
Okay, I don't see why CoreDump would need to use finer-grained locking thank Save,
Well, my point is that we really should make both of them have finer-grained locking, since they are potentially very long operations (think of a guest with a large amount of memory). But we can go back and fix them both later.
ACK,
Thanks, I've pushed this now. -- Chris Lalancette