* Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Mon, 26 Jan 2009 22:27:27 +0100 > Ingo Molnar <mingo@xxxxxxx> wrote: > > > > > * Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > > > So if it's generic it ought to be implemented in a generic way - not a > > > > "dont use from any codepath that has a lock held that might > > > > occasionally also be held in a keventd worklet". (which is a totally > > > > unmaintainable proposition and which would just cause repeat bugs > > > > again and again.) > > > > > > That's different. The core fault here lies in the keventd workqueue > > > handling code. If we're flushing work A then we shouldn't go and > > > block behind unrelated work B. > > > > the blocking is inherent in the concept of "a queue of worklets > > handled by a single thread". > > > > If a worklet is blocked then all other work performed by that thread > > is blocked as well. So by waiting on a piece of work in the queue, we > > wait for all prior work queued up there as well. > > > > The only way to decouple that and to make them independent (and hence > > independently flushable) is to create more parallel flows of > > execution: i.e. by creating another thread (another workqueue). > > > > Nope. As I said, the caller of flush_work() can detach the work item > and run it directly. that would change the concept of execution but indeed it would be interesting to try. It's outside the scope of late -rcs i guess, but worthwile nevertheless. Ingo -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
