On Thu, Apr 25, 2013 at 10:17:35AM -0700, H. Peter Anvin wrote: > On 04/25/2013 10:06 AM, Oleg Nesterov wrote: > >> > >> The downside is that in userland perf tool we need differing documentation > >> on what the mask syntax means for each architecture. > > > > Personally I think this is acceptable. > > > > But I am new to this code, so... > > > > That would seem really, really awkward. Yes, perf has a bunch of > low-level stuff, but it would seem highly undesirable to force the user > to deal with something like that. > > It would be good to have a user-friendly syntax that covers most of what > users may want to do and perhaps a longer form that can express > everything including ARM's byte selects; if the system can't honor the > request it should return an error.
Okay, If arch specific masks are a no go, then I think I'm convinced that Oleg's idea of using bp_len is the right thing to do. Right now perf userland tool hard codes bp_len to 4, so I need to modify it to allow user to override the length if desired. Oleg, Frederic, et al. Which syntax do you prefer? If we want to set bp_len to 16: $ perf stat -e mem:0x1000:rw:16 Or $ perf stat -e mem:0x1000:16 Or $ perf stat -e mem:0x1000/16 If no bp_len value is specified, it will still default to 4 as it did before. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
