One of the things I’ve been doing these past few months is running Mochitests on Valgrind on a semi-regular basis — roughly weekly — and trying to drive the resultant error count down to zero. I did this some years … Continue reading
Valgrind support on Yosemite has improved significantly in the past few months. It is now feasible to run Firefox on Valgrind on Yosemite. Support for 10.9 (Mavericks) has also improved, but 64-bit Yosemite remains the primary focus of support work. … Continue reading
Following some sterling hackery by Alexander Potapenko and Philippe Waroquiers, Valgrind/Memcheck now has direct support for JEMalloc, tcmalloc, and any other allocation library offering a malloc-style interface. This means you no longer need to build Firefox using –disable-jemalloc on Linux. … Continue reading
Various sets of fixes have been committed for Valgrind on Lion. It now works well enough to run 64 bit Firefox builds and get sane results. 32 bit builds run too, but appear to hang, for threading related reasons I … Continue reading
This is a long post. Here’s a summary. the good news: Valgrind’s Memcheck tool now works well enough on Nexus S that it can run Firefox and find real bugs, for example bug 688733. The false error rate from Memcheck … Continue reading
Valgrind’s Memcheck tool works on Linux and MacOS, but not on Windows. Interestingly, there is something like it for Windows: “Dr Memory”. Similar in style to Memcheck, Dr Memory is an open source memory checking tool built on top of … Continue reading
Last August I asked the question “How fast can CFI/EXIDX-based stack unwinding be?” At the time I was experimenting with native unwinding using our in-tree Breakpad copy, but getting dismal performance results. The posting observed that Breakpad’s CFI unwinder is … Continue reading
In last week’s episode of The Wonderful World of CFI Unwinding we looked at how fast it could be done. This week we’re going to look at how compactly the unwind information can be stored. But I know you want … Continue reading
This is a long post. Here’s a summary. Valgrind unwinds CFI typically 30 times faster than Breakpad. Bad though that sounds, it’s really encouraging. If we can get even half that speedup — that is, 15 times faster than at … Continue reading
On Android, we have a couple of ways to periodically extract stack traces from a running Firefox: the built in profiler, and Valgrind. In principle oprofile could also produce stacks at intervals, although it doesn’t. Looking at zillions of stacks, … Continue reading
