On Mon, Feb 25, 2019 at 07:04:01PM -0800, Andi Kleen wrote: > [Changes: > Removed already merged patches. > Address review feedback, see individual patches. > Now compiles with gcc 8. > Some minor bug fixes and improvements.] > > We currently have two ways to look at sample data in perf: > either use perf report to aggregate everything, or use > perf script to look at all individual samples. > > Both ways are useful. Of course aggregation is useful > to quickly find the most expensive part of the code. > > But sometimes a single sample is not good enough to > determine the problem and we need to look at context, either > through branch contexts, or other previous samples (e.g. for > correlating different micro architecture events or computing > metrics) > > This can be done through perf script today, but it can > be rather cumbersome to find the right samples to look > at. > > Another problem with perf report is that it aggregates > the whole measurement period. But many real workloads > have phases where they behave quite differently, and it is > often not useful to combine them into a single histogram. > > While this can be worked around with the --time option > to report, it can be quite cumbersome. > > This patch kit attempts to address some of these > problems in perf report by making it time aware. > > - It adds a new time sort key that allows perf report > to separate samples from different regions. The time > regions can be defined with a new --time-quantum option. > > - Then it extends the perf script support in the > tui record browser to allow browsing samples for > different time regions from within a perf report > session. > > - Extends the report browser script display > to automatically select sensible defaults > based on what was recorded. For example it will > automatically show branch contexts with -b. > > - Support browsing the context of individual samples. > perf report can save a limited number of random samples > per histogram entry with the new --samples option. > Then the browser allows directly jumping to any > of the saved samples and browsing the context on the current > thread or CPU. > > There could be probably be done more to make > perf report even better for such use cases (e.g. a real > time line display), but this basic support is good > enough for many useful usages. > > Also available in > git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-misc.git perf/streams-2
your post is missing this patch, it's only in the branch: perf tools: Add utility function to fetch executable jirka
