[ltt-dev] [PATCH] Add tracepoints to track pagecache transition

[fche@redhat.com (Frank Ch. Eigler)]

Atsushi Tsuji <a-tsuji at bk.jp.nec.com> writes:

> I thought it would be useful to trace pagecache behavior for problem
> analysis (performance bottlenecks, behavior differences between stable
> time and trouble time).

Interesting!  I hope it inspires more thinking about more places and
ways for graphical data visualization to apply.

> By using those tracepoints, we can describe and visualize pagecache
> transition (file-by-file basis) in kernel and pagecache consumes
> most of the memory in running system and pagecache hit rate and
> writeback behavior will influence system load and performance.

To what extent does your script work if it uses kprobes-based
kernel.function() probes?  (It can use "!" type probe point
decorations to automatically adapt to the preferred presence of the
tracepoints/markers.)

> I attached an example which is visualization of pagecache status
> using SystemTap. [...]

Would you consider sharing this script?


- FChE