Since Python 3.6, you can use PYTHONMALLOC=malloc for Valgrind: it avoids false alarms produced by the pymalloc allocator.
Victor Le mar. 16 avr. 2019 à 12:09, Nathaniel Smith <n...@pobox.com> a écrit : > > On Mon, Apr 15, 2019 at 8:58 PM Michael Sullivan <su...@msully.net> wrote: > > > > On Mon, Apr 15, 2019 at 4:06 PM Nathaniel Smith <n...@pobox.com> wrote: > >> > >> On Mon, Apr 15, 2019, 15:27 Michael Sullivan <su...@msully.net> wrote: > >>> > >>> > The main question is if anyone ever used Py_TRACE_REFS? Does someone > >>> > use sys.getobjects() or PYTHONDUMPREFS environment variable? > >>> > >>> I used sys.getobjects() today to track down a memory leak in the > >>> mypyc-compiled version of mypy. > >>> > >>> We were leaking memory badly but no sign of the leak was showing up in > >>> mypy's gc.get_objects() based profiler. Using a debug build and switching > >>> to sys.getobjects() showed that we were badly leaking int objects. A > >>> quick inspection of the values in question (large and random looking) > >>> suggested we were leaking hash values, and that quickly pointed me to > >>> https://github.com/mypyc/mypyc/pull/562. > >>> > >>> I don't have any strong feelings about whether to keep it in the > >>> "default" debug build, though. I was using a debug build that I built > >>> myself with every debug feature that seemed potentially useful. > >> > >> > >> This is mostly to satisfy my curiosity, so feel free to ignore: did you > >> try using address sanitizer or valgrind? > >> > > I didn't, mostly because I assume that valgrind wouldn't play well with > > cpython. (I've never used address sanitizer.) > > > > I was curious, so I went back and tried it out. > > It turned out to not seem to need that much fiddling to get to work. It > > slows things down a *lot* and produced 17,000 "loss records", though, so > > maybe I don't have it working right. At a glance the records did not shed > > any light. > > > > I'd definitely believe that valgrind is up to the task of debugging this, > > but my initial take with it shed much less light than my sys.getobjects() > > approach. (Though note that my sys.getobjects() approach was slotting it > > into an existing python memory profiler we had hacked up, so...) > > valgrind on CPython is definitely a bit fiddly – if you need it again > you might check out Misc/README.valgrind. > > Supposedly memory sanitizer is just './configure > --with-memory-sanitizer', but I haven't tried it either :-) > > -n > > -- > Nathaniel J. Smith -- https://vorpus.org > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > https://mail.python.org/mailman/options/python-dev/vstinner%40redhat.com -- Night gathers, and now my watch begins. It shall not end until my death. _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
