If a thread is unable to start a job (e.g. because of timeout) an warning is printed into the logs. So far, the message does not contain agent job info. Add it as it might help future debugging. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_domain.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index d7c0598cee..827597d5f3 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -6422,6 +6422,7 @@ qemuDomainObjBeginJobInternal(virQEMUDriverPtr driver, const char *blocker = NULL; int ret = -1; unsigned long long duration = 0; + unsigned long long agentDuration = 0; unsigned long long asyncDuration = 0; VIR_DEBUG("Starting job: job=%s agentJob=%s asyncJob=%s " @@ -6526,22 +6527,27 @@ qemuDomainObjBeginJobInternal(virQEMUDriverPtr driver, ignore_value(virTimeMillisNow(&now)); if (priv->job.active && priv->job.started) duration = now - priv->job.started; + if (priv->job.agentActive && priv->job.agentStarted) + agentDuration = now - priv->job.agentStarted; if (priv->job.asyncJob && priv->job.asyncStarted) asyncDuration = now - priv->job.asyncStarted; - VIR_WARN("Cannot start job (%s, %s) for domain %s; " - "current job is (%s, %s) " - "owned by (%llu %s, %llu %s (flags=0x%lx)) " - "for (%llus, %llus)", + VIR_WARN("Cannot start job (%s, %s, %s) for domain %s; " + "current job is (%s, %s, %s) " + "owned by (%llu %s, %llu %s, %llu %s (flags=0x%lx)) " + "for (%llus, %llus, %llus)", qemuDomainJobTypeToString(job), + qemuDomainAgentJobTypeToString(agentJob), qemuDomainAsyncJobTypeToString(asyncJob), obj->def->name, qemuDomainJobTypeToString(priv->job.active), + qemuDomainAgentJobTypeToString(priv->job.agentActive), qemuDomainAsyncJobTypeToString(priv->job.asyncJob), priv->job.owner, NULLSTR(priv->job.ownerAPI), + priv->job.agentOwner, NULLSTR(priv->job.agentOwnerAPI), priv->job.asyncOwner, NULLSTR(priv->job.asyncOwnerAPI), priv->job.apiFlags, - duration / 1000, asyncDuration / 1000); + duration / 1000, agentDuration / 1000, asyncDuration / 1000); if (nested || qemuDomainNestedJobAllowed(priv, job)) blocker = priv->job.ownerAPI; -- 2.16.4

If a thread is unable to acquire a job (e.g. because of timeout) an error is reported and the error message contains reference to the other thread holding the job. Well, the error message should report agent job too as it is yet another source of possible failure. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_domain.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 827597d5f3..4331b95917 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -6420,6 +6420,7 @@ qemuDomainObjBeginJobInternal(virQEMUDriverPtr driver, bool async = job == QEMU_JOB_ASYNC; virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver); const char *blocker = NULL; + const char *agentBlocker = NULL; int ret = -1; unsigned long long duration = 0; unsigned long long agentDuration = 0; @@ -6549,16 +6550,21 @@ qemuDomainObjBeginJobInternal(virQEMUDriverPtr driver, priv->job.apiFlags, duration / 1000, agentDuration / 1000, asyncDuration / 1000); - if (nested || qemuDomainNestedJobAllowed(priv, job)) - blocker = priv->job.ownerAPI; - else - blocker = priv->job.asyncOwnerAPI; + if (job) { + if (nested || qemuDomainNestedJobAllowed(priv, job)) + blocker = priv->job.ownerAPI; + else + blocker = priv->job.asyncOwnerAPI; + } + + if (agentJob) + agentBlocker = priv->job.agentOwnerAPI; if (errno == ETIMEDOUT) { - if (blocker) { + if (blocker || agentBlocker) { virReportError(VIR_ERR_OPERATION_TIMEOUT, - _("cannot acquire state change lock (held by %s)"), - blocker); + _("cannot acquire state change lock (held by %s %s)"), + NULLSTR(blocker), NULLSTR(agentBlocker)); } else { virReportError(VIR_ERR_OPERATION_TIMEOUT, "%s", _("cannot acquire state change lock")); @@ -6566,11 +6572,11 @@ qemuDomainObjBeginJobInternal(virQEMUDriverPtr driver, ret = -2; } else if (cfg->maxQueuedJobs && priv->jobs_queued > cfg->maxQueuedJobs) { - if (blocker) { + if (blocker || agentBlocker) { virReportError(VIR_ERR_OPERATION_FAILED, - _("cannot acquire state change lock (held by %s) " + _("cannot acquire state change lock (held by %s %s) " "due to max_queued limit"), - blocker); + NULLSTR(blocker), NULLSTR(agentBlocker)); } else { virReportError(VIR_ERR_OPERATION_FAILED, "%s", _("cannot acquire state change lock " -- 2.16.4

On 06/22/2018 10:07 AM, Jiri Denemark wrote: I thought about it too, but then decided to take the easy way out because this would end up being a spaghetti code in my sight. But okay, I will rework this to: if (blocker && agentBlocker) { ... } else if (blocker) { ... } else if (agentBlocker) { ... } else { ... } where all four bodies are merely the same (only the error message would change - hence the spaghetti code). Michal