Valgrind 3.15.0 with improved DHAT heap profiler

Posted on April 17, 2019, 23:00.

Julian Seward released valgrind 3.15.0 which updates support for existing platforms and adds a major overhaul of the DHAT heap profiler.  There are, as ever, many refinements and bug fixes.  The release notes give more details.

Nicholas Nethercote used the old experimental DHAT tool a lot while profiling the Rust compiler and then decided to write and contribute A better DHAT (which contains a screenshot of the the new graphical viewer).

CORE CHANGES

  • The XTree Massif output format now makes use of the information obtained when specifying --read-inline-info=yes.
  • amd64 (x86_64): the RDRAND and F16C insn set extensions are now supported.

TOOL CHANGES

DHAT

  • DHAT been thoroughly overhauled, improved, and given a GUI.  As a result, it has been promoted from an experimental tool to a regular tool.  Run it with --tool=dhat instead of --tool=exp-dhat.
  • DHAT now prints only minimal data when the program ends, instead writing the bulk of the profiling data to a file.  As a result, the --show-top-n and --sort-by options have been removed.
  • Profile results can be viewed with the new viewer, dh_view.html.  When a run ends, a short message is printed, explaining how to view the result.
  • See the documentation for more details.

Cachegrind

  • cg_annotate has a new option, --show-percs, which prints percentages next to all event counts.

Callgrind

  • callgrind_annotate has a new option, --show-percs, which prints percentages next to all event counts.
  • callgrind_annotate now inserts commas in call counts, and sort the caller/callee lists in the call tree.

Massif

  • The default value for --read-inline-info is now yes on Linux/Android/Solaris. It is still no on other OS.

Memcheck

  • The option --xtree-leak=yes (to output leak result in xtree format) automatically activates the option --show-leak-kinds=all, as xtree visualisation tools such as kcachegrind can in any case select what kind of leak to visualise.
  • There has been further work to avoid false positives.  In particular, integer equality on partially defined inputs (C == and !=) is now handled better.

OTHER CHANGES

  • The new option --show-error-list=no|yes displays, at the end of the run, the list of detected errors and the used suppressions.  Prior to this change, showing this information could only be done by specifying -v -v, but that also produced a lot of other possibly-non-useful messages.  The option -s is equivalent to --show-error-list=yes.
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