On Tue, Feb 02, 2016 at 11:27:34AM -0300, Arnaldo Carvalho de Melo wrote: > Em Tue, Feb 02, 2016 at 11:15:35PM +0900, Namhyung Kim escreveu: > > On Tue, Feb 02, 2016 at 10:55:34AM -0300, Arnaldo Carvalho de Melo wrote: > > > Em Tue, Feb 02, 2016 at 10:05:37PM +0900, Namhyung Kim escreveu: > > > > Hi Arnaldo, > > > > > > > > On Mon, Feb 01, 2016 at 05:19:36PM -0300, Arnaldo Carvalho de Melo > > > > wrote: > > > > > Em Thu, Jan 28, 2016 at 12:40:50AM +0900, Namhyung Kim escreveu: > > > > > > Currently --percent-limit option only works for hist entries. > > > > > > However > > > > > > it'd be better to have same effect to callchains as well > > > > > > > > > > Documentation needs updating? It says: > > > > > > > > > > --percent-limit:: > > > > > Do not show entries which have an overhead under that percent. > > > > > (Default: 0). > > > > > > > > Right. Is it ok to you? > > > > > > > > --percent-limit:: > > > > Do not show entries and callchains which have an overhead under > > > > that > > > > percent. (Default: 0). > > > > > > Ok, but is the default zero? > > > > > > That was what I was alluding to, as as soon as I applied the patch that > > > made callchains honour this limit, about 60% of the entries in the > > > particular perf.data file I was 'perf report'ing lost its '+' (callchain > > > expansion) signs. > > > > Yes, and this is what I want to say too. :) > > > > The default value of percent limit is different for hist entry and > > callchains. For hist entry the default is 0, and for callchains it's > > 0.5%. But using --percent-limit option, we can set both at once from > > now on. > > > > Before this patchset, percent limit of callchains didn't checked. > > Once applied, users can see callchains are disppeared like your case. > > This is just because 0.5% of the default limit for callchains is too > > high IMHO - I guess it was originally set for 'fractal' mode which > > calculates relative percents. So I proposed to change the default in > > the patch 10/10 but Andi thoughts 0.005% was too small. We need to > > choose other value like 0.05% ? > > Unsure about the limit, but please fold the nice explanation you gave > about the limits for hist entries and callchains and how the defaults > are different, and how they can be set at once using --percent-limit.
Ok, will do. > > Also, would it be overengineering to allow optionally set two limits, > one for hists and one for callchains? I.e. like: > > --percent-limit 1,0.07 > > Then: > > --percent-limit 0.8 > > would be the same as: > > --percent-limit 0.8,0.8 Originally, the percent limit (threshold) for callchains can be set using -g/--call-graph option. What Andi asked is to set both limits using a single option. Not sure it's worth adding another way to specify the callchain limit. Thanks, Namhyung
