On 07/21/2014 11:02 AM, Jiri Olsa wrote: > On Mon, Jul 21, 2014 at 09:43:58AM +0300, Adrian Hunter wrote: >> On 07/21/2014 12:55 AM, Jiri Olsa wrote: >>> hi, >>> this patchset factors session's ordered samples queue, >>> and allows to limit the size of this queue. >>> >>> v3 changes: >>> - rebased to latest tip/perf/core >>> - add comment for WARN in patch 8 (David) >>> - added ordered-events debug variable (David) >>> - renamed ordered_events_(get|put) to ordered_events_(new|delete) >>> - renamed struct ordered_events_queue to struct ordered_events >>> >>> v2 changes: >>> - several small changes for review comments (Namhyung) >>> >>> >>> The report command queues events till any of following >>> conditions is reached: >>> - PERF_RECORD_FINISHED_ROUND event is processed >>> - end of the file is reached >>> >>> Any of above conditions will force the queue to flush some >>> events while keeping all allocated memory for next events. >>> >>> If PERF_RECORD_FINISHED_ROUND is missing the queue will >> >> Why is it missing? > > it's stored only for tracepoints now patch 17 fixies that
Wouldn't that make a huge difference all by itself? I would make that the first patch, and measure the difference that it makes by itself. > >> >>> allocate memory for every single event in the perf.data. >>> This could lead to enormous memory consuption and speed >>> degradation of report command for huge perf.data files. >>> >>> With the quue allocation limit of 100 MB, I've got around >>> 15% speedup on reporting of ~10GB perf.data file. >> >> How do you know the results are still valid? Wouldn't it >> be better to wait that extra 15% and know that the data has >> been processed correctly? > > The HALF flush could cause the out of order message > (which I get occasionaly anyway). Patch 19 allows Occasional out-of-order messages would be worth investigating IMHO. Either there is a bug or there is some "interesting" data being recorded. > out of order events after HALF flush. > > The main reason for me was to control the memory allocation, > which could get enormous without ROUND events being stored. But now you are storing them... > The 100MB queue limit seems to be enough not to hit out of > order event due to the HALF flush. ...so is the 100MB limit needed at all if you have ROUND events? -- 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/
