On Fri, Dec 13, 2019 at 01:29:41PM -0500, Steven Rostedt wrote: > On Fri, 13 Dec 2019 19:02:23 +0100 > Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > > On Fri, Dec 13, 2019 at 12:11:18PM -0500, Steven Rostedt wrote: > > > On Fri, 13 Dec 2019 08:51:57 -0800 > > > Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote: > > > > > > > It had two choices. Both valid. I don't know why gdb picked this one. > > > > So yeah I think renaming 'ring_buffer' either in ftrace or in perf would be > > > > good. I think renaming ftrace one would be better, since gdb picked perf one > > > > for whatever reason. > > > > > > Because of the sort algorithm. But from a technical perspective, the > > > ring buffer that ftrace uses is generic, where the perf ring buffer can > > > only be used for perf. Call it "event_ring_buffer" or whatever, but > > > it's not generic and should not have a generic name. > > > > Your ring buffer was so generic that I gave up trying to use it after > > trying for days :-( (the fundamental problem was that it was impossible > > to have a single cpu buffer; afaik that is still true today) > > Yeah, but that could have been fixed, and the only reason it's not > today, is because it requires more overhead to do so. > > IIRC, the main reason that you didn't use it then, is because it wasn't > fully lockless at the time (it is today), and you couldn't use it from > NMI context. > > > > > Nor is the perf buffer fundamentally specific to perf, but there not > > being another user means there has been very little effort to remove > > perf specific things from it. > > I took a look at doing so, and it was not a trivial task. > > > > > There are major design differences between them, which is > > unquestionably, but I don't think it is fair to say one is more or less > > generic. > > > > How about we rename both? I'm a bit adverse to long names, so how about > > we rename the perf one to perf_buffer and the trace one to trace_buffer? > > I'm fine with this idea! Now what do we call the ring buffer that > tracing uses, as it is not specific for tracing, it was optimized for > splicing. But sure, I can rename it to trace_buffer. I just finished > renaming perf's... > > Thinking about this, perhaps we should remove the word "ring" from > both. That is: > > perf_buffer and trace_buffer ? sounds good to me.. and too good to be true ;-) please let me know if I should send the perf change thanks, jirka
