Messages in this thread | | | Subject | Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) | From | David Ahern <> | Date | Mon, 14 Dec 2015 07:55:32 -0700 |
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On 12/14/15 2:38 AM, Ingo Molnar wrote: > >> And in an unrelated note, I absolutely detest --buildid being the >> default, it makes perf-record blow chunks.
Yes, a .debug directory that gets bloated fast and being a dot-directory is off the primary radar. I forget about it and too often forget to add the option to disable it.
> > So I'd absolutely _love_ to split up the singular perf.data into a hierarchy of > files in a .perf directory, with a structure like this (4-core system): > > .perf/cmdline > .perf/features > .perf/evlist > .perf/ring_buffers/cpu0/raw.trace > .perf/ring_buffers/cpu1/raw.trace > .perf/ring_buffers/cpu2/raw.trace > .perf/ring_buffers/cpu3/raw.trace > ...
On a related note why a .perf directory?
> > I.e. the current single file format of perf.data would be split up into individual > files. Each CPU would get its own trace file output - any sorting and ordering > would be done afterwards. 'perf record' itself would never by default have to do > any of that, it's a pure recording session. > > 'perf archive' would still create a single file to make transport between machines > easy. > > perf.data.old would be replaced by a .perf.old directory or so. > > Debugging would be easier too I think, as there's no complex perf data format > anymore, it's all in individual (typically text, or binary dump) files in the > .perf directory. > > This would solve all the scalability problems - and would make the format more > extensible and generally more accessible as well. > > What do you think?
Big change to user experience.
I realize perf-archive has been around since I started using perf in mid-2010, but I for one never use it. I suspect it is not widely used (definitely not in the circles I have been involved and helped with perf), so suddenly requiring it is a change in user experience.
The only 2 files on the system I pull off the box are kallsyms and perf.data. Most of the systems where I use perf have limited symbols and there is nothing in .debug I need to pull of the box.
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