[RFC 0/4] perf tools: Add hist_entry allocation callbacks

[Jiri Olsa <jolsa@kernel.org>]

hi,
this patchset tries to add support provide own allocation
zalloc/free methods for hist_entry object.

The reason is to provide a way to be able to store more
data within hist_entry object in a transparent way to
its current usage by allocating its own hist_entry sub
object.

The user/app which wants to allocate its own hist_entry
sub object provides following ops struct:

  struct hist_entry_ops *ops {
    void*   (*new)(size_t);
    void    (*free)(void *);
  }

via new interface function:

  struct hist_entry *
  hists__add_entry_ops(struct hists *hists,
                       struct hist_entry_ops *ops,
                       ...

I'm using this for c2c code to enlarge hist_entry object
with large stats structure, which has no use to standard
perf usage/commands.

It might be used to lower the hist_entry footproint for
default perf usage by uing this for things like hierarchy
output that adds extra stuff into hist_entry object.

Available at:
  git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
  perf/he_ops

thanks for comments,
jirka


---
Jiri Olsa (4):
      perf tools: Introduce hist_entry__init function
      perf tools: Do the error path hist_entry release in hist_entry__new
      perf tools: Introduce hist_entry_ops
      perf tools: Introduce hists__add_entry_ops function

 tools/perf/util/hist.c | 204 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------------------------------
 tools/perf/util/hist.h |  11 ++++++
 tools/perf/util/sort.h |   6 ++++
 3 files changed, 148 insertions(+), 73 deletions(-)