Re: [libvirt] [PATCH] Fix performance & reliabilty of QMP probing

On 01/24/2013 11:34 AM, Daniel P. Berrange wrote: > From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; > @@ -916,11 +917,19 @@ virCapsPtr qemuCapsInit(qemuCapsCachePtr cache) > * so just probe for them all - we gracefully fail > * if a qemu-system-$ARCH binary can't be found > */ > - for (i = 0 ; i < VIR_ARCH_LAST ; i++) > + unsigned long long a, b; What are 'a' and 'b' for?

> + for (i = 0 ; i < VIR_ARCH_LAST ; i++) { > + unsigned long long start, end; > + if (virTimeMillisNow(&start) < 0) > + goto error; > if (qemuCapsInitGuest(caps, cache, > virArchFromHost(), > i) < 0) > goto error; > + if (virTimeMillisNow(&end) < 0) > + goto error; > + VIR_DEBUG("Probed %s in %llums", virArchToString(i), end-start); spaces around '-'

> + } > > /* QEMU Requires an emulator in the XML */ > virCapabilitiesSetEmulatorRequired(caps); > @@ -2291,7 +2300,6 @@ qemuCapsInitQMPBasic(qemuCapsPtr caps) > static int > qemuCapsInitQMP(qemuCapsPtr caps, > const char *libDir, > - const char *runDir, > uid_t runUid, > gid_t runGid) > { > @@ -2324,8 +2332,11 @@ qemuCapsInitQMP(qemuCapsPtr caps, > > /* ".pidfile" suffix is used rather than ".pid" to avoid a possible clash > * with a qemu domain called "capabilities" > + * Normally we'd use runDir for pid files, but because we're using > + * -daemonize we need QEMU to be allowed to create them, rather > + * than libvirtd. So we're using libDir which QEMU can write to > */ > - if (virAsprintf(&pidfile, "%s/%s", runDir, "capabilities.pidfile") < 0) { > + if (virAsprintf(&pidfile, "%s/%s", libDir, "capabilities.pidfile") < 0) { Will this change work across an upgrade? That is, if I have a qemu already running under libvirtd with the pid file in the old location, and then restart to a newer libvirtd, do we ever try to read the pidfile again, and fail because it is not in the right location?