On Wed, Feb 9, 2022 at 1:09 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > On Tue, Feb 08, 2022 at 10:41:56AM -0800, Namhyung Kim wrote: > > > Eventually I'm mostly interested in the contended locks only and I > > want to reduce the overhead in the fast path. By moving that, it'd be > > easy to track contended locks with timing by using two tracepoints. > > So why not put in two new tracepoints and call it a day? > > Why muck about with all that lockdep stuff just to preserve the name > (and in the process continue to blow up data structures etc..). This > leaves distros in a bind, will they enable this config and provide > tracepoints while bloating the data structures and destroying things > like lockref (which relies on sizeof(spinlock_t)), or not provide this > at all. If it's only lockref, is it possible to change it to use arch_spinlock_t so that it can remain in 4 bytes? It'd be really nice if we can keep spin lock size, but it'd be easier to carry the name with it for analysis IMHO. Thanks, Namhyung
