Il 27/09/2012 14:45, Kevin Wolf ha scritto: > Am 27.09.2012 14:27, schrieb Paolo Bonzini: >> Il 27/09/2012 14:18, Kevin Wolf ha scritto: >>>>> >>>>> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> >>> I think there's a problem with terminology at least. What does "paused" >>> really mean? Is it that the job has been requested to pause, or that it >>> has actually yielded and is inactive? >>> >>> The commit message seems to use the latter semantics (which I would >>> consider the intuitive one), >> >> You mean this: "Paused jobs cannot be canceled without first resuming >> them". I can add a specification, like "(even if the job actually has >> not reached the sleeping point and thus is still running)". > > I actually meant "pause happens at the next sleeping point", which isn't > unspecific at all.
Hmm, there are two aspects: 1) when things stop running; 2) when the job reports itself to be paused. The commit message describes (1) precisely, and doesn't say anything about (2). That's too specific for a commit message, but the header file describes it precisely. However, in the QMP documentation, the good comment for "bool paused;" must be replicated in BlockJobInfo's "paused" member. >> From the QMP client's point of view it doesn't really matter, does it? >> >> - even after a job that writes to disk X has "really" paused, you cannot >> read or write disk X. It's still owned by QEMU, it hasn't been flushed, >> it may play games like lazy refcounts. > > I'm not sure about this one. Consider things like a built-in NBD server. > Probably we'll find more cases in the future, where some monitor command > might seem to be safe while a job is paused. Ok, that's a good point. I'll add a "busy" member to BlockJobInfo. Paolo