Alan Stern wrote, On 12/04/2007 08:28 PM: > On Tue, 4 Dec 2007, Jarek Poplawski wrote: ... > But you have to consider hypothetical kernel bugs. That's exactly what > lockdep is for -- to warn you about possible deadlocks that could be > caused by bugs. > > As a simple example, if thread #1 does "lock(A); lock(B)" and thread > #2 does "lock(B); lock(A)" then there's a possible bug. Lockdep should > warn about you, and it does -- even if those two threads can never run > at the same time. > > If lockdep warned about deadlocks only when they actually happened, it > wouldn't be nearly so useful. Sure! I probably missed your point... Lockdep always names reported locks, so I meant 'hypothetical' only trying to explain lockdep with some other, unknown or unnamed bugs. So, depending on the code, above example with A & B could be a real bug (even if very improbable but logically justified) or a false alarm (eg. when we know both threads could never work at the same). Jarek P. _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
