On Wed, Jun 25, 2014 at 02:09:31PM +0300, Alexander Shishkin wrote: > Peter Zijlstra <[email protected]> writes: > > > On Wed, Jun 11, 2014 at 06:41:45PM +0300, Alexander Shishkin wrote: > >> + /* > >> + * Set up pmu-private data structures for an AUX area > >> + */ > >> + void *(*setup_aux) (int cpu, void **pages, > >> + int nr_pages, bool overwrite); > >> + /* optional */ > >> + > >> + /* > >> + * Free pmu-private AUX data structures > >> + */ > >> + void (*free_aux) (void *aux); /* optional */ > > > > I was hoping you could replace those with a PERF_CAP_AUX or something > > and then have one generic allocation routine like you provide in the > > subsequent patches. > > I need these to allocate pmu-specific SG tables now, which I don't see > how to generalize nicely. User-visible aux_pages are allocated in the > generic rb_alloc_aux(). > > As for sg tables, the alternative would be to allocate them in the > event::pmu::add() path, which is probably not very good for > performance, unless I'm missing something? Like, I can allocate stuff in > the first add() and then free it in event::destroy(). > > Or, we can assume a generic sg table format and allocate them in the > generic code, but then we'll need more capabilities to indicate at least > the size of a table entry. PT needs 64 bits per entry, ARM's TMC needs > 32 and the non-SG PT will still need some tables. But I'd rather leave > this part to the pmu drivers. What do you think?
Ah, I wasn't aware.. too bad. Maybe add this to the changelog. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
