After discussions with the people from Google we learned that a large part of memory consumption in Firefox ASan builds is probably caused by allocations that happen in deep stacks. Since ASan records the stack on each malloc and free, this can quickly fill up a lot of memory. Hence we decided to limit the amount of stack frames saved by default to 20. This value can still be increased by the ASAN_OPTIONS environment variable if necessary.

Comment on attachment 8994663 [details] Bug 1478143 - Adjust default malloc_context_size for ASan builds. https://reviewboard.mozilla.org/r/259170/#review266196

Pushed by choller@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/f7b56df2e870 Adjust default malloc_context_size for ASan builds. r=froydnj

Backed out for wpt failures on Linux asan. Log link: https://treeherder.mozilla.org/logviewer.html#?job_id=189915370&repo=mozilla-inbound&lineNumber=118938 Backout link: https://hg.mozilla.org/integration/mozilla-inbound/rev/48b56ef2441d0c7fbf6f838f6fb99b961985bb6a

Pushed by choller@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/86bf4fd84b05 Adjust default malloc_context_size for ASan builds. r=froydnj

Nathan, I just repushed this with an #ifdef MOZ_ASAN_REPORTER around it because of wpt failures. The failures are LeakSanitizer reports apparently, which means that there is a suppression/whitelist somewhere that uses stack frames higher than the 20th frame to suppress these leaks. Which also means that we are not running these tests with a setting of 5 as you mentioned. Maybe you want to look into that and confirm that is what you expected to be there?

I was going off of: https://searchfox.org/mozilla-central/search?q=malloc_context_size&path= It's not clear to me what suppression file is being used (build/sanitizers/lsan_suppressions.txt doesn't list anything that would obviously be higher on the stack from those leaks), but perhaps wpt doesn't run via any of those Python files that set malloc_context_size?