Hi Don, On Wed, 9 Apr 2014 09:57:06 -0400, Don Zickus wrote: > On Wed, Apr 09, 2014 at 02:31:00PM +0900, Namhyung Kim wrote: >> On Mon, 24 Mar 2014 15:34:36 -0400, Don Zickus wrote: >> > The cache contention tools needs to keep all the perf records unique in >> > order >> > to properly parse all the data. Currently add_hist_entry() will combine >> > the duplicate record and add the weight/period to the existing record. >> > >> > This throws away the unique data the cache contention tool needs (mainly >> > the data source). Create a flag to force the records to stay unique. >> >> No. This is why I said you need to add 'mem' and 'snoop' sort keys into >> the c2c tool. This is not how sort works IMHO - if you need to make >> samples unique let the sort key(s) distinguish them somehow, or you can >> combine same samples (in terms of sort kes) and use the combined entry's >> stat.nr_events and stat.period or weight. > > Ok. I understand your point. Perhaps this was my lack of fully > understanding the sorting algorithm when I did this. I can look into > adding the 'mem' and 'snoop'. > > One concern I do have is we were caculating statistics based on the weight > (mean, median, stddev). I was afraid that combining the entries would > throw off our calculations as we could no longer accurately determine them > any more. Is that true?
Yes, if you want to calculate the stats accurately, it needs to be done when processing samples not hist_entries IMHO. Thanks, Namhyung -- 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/
