Hi Folks! The Fission MemShrink project has been chugging along quite nicely and a ton of progress has been made over the past month. There's been a large focus on reducing the JS memory usage and we've managed to drop the base content JS measure <https://treeherder.mozilla.org/perf.html#/graphs?timerange=2592000&series=autoland,1684872,1,4> by ~1.1MB (17%) [1]:
[image: https://screenshotscdn.firefoxusercontent.com/images/c5046573-91bd-4ca1-98db-6290777e70c4.png] Additionally we've started looking at the overhead of our many threads <https://bugzilla.mozilla.org/show_bug.cgi?id=1476432> [2], drafted up some ideas on reducing relocation overhead by adopting a fork server <https://bugzilla.mozilla.org/show_bug.cgi?id=1470591> on linux/mac [3], and we're looking at reducing the overhead of per process font related data <https://bugzilla.mozilla.org/show_bug.cgi?id=648417> [4]. Below is a sampling of the bugs that have improved memory usage over the past month, apologies if I left any off! Please feel free to point out other improvements. All numbers are *per content process*. *JS improvements* - In a great example of every little bit counts, *Kris Maglione* reduced memory usage by *405KB* in various bugs that made us lazily load JS content (Bug 1472491 <https://bugzilla.mozilla.org/show_bug.cgi?id=1472491>, Bug 1473631 <https://bugzilla.mozilla.org/show_bug.cgi?id=1473631>, Bug 1474139 <https://bugzilla.mozilla.org/show_bug.cgi?id=1474139>, Bug 1474155 <https://bugzilla.mozilla.org/show_bug.cgi?id=1474155>, Bug 1479241 <https://bugzilla.mozilla.org/show_bug.cgi?id=1479241>, Bug 1479245 <https://bugzilla.mozilla.org/show_bug.cgi?id=1479245>, Bug 1479309 <https://bugzilla.mozilla.org/show_bug.cgi?id=1479309>, Bug 1479310 <https://bugzilla.mozilla.org/show_bug.cgi?id=1479310>, Bug 1479312 <https://bugzilla.mozilla.org/show_bug.cgi?id=1479312>, Bug 1479313 <https://bugzilla.mozilla.org/show_bug.cgi?id=1479313>, Bug 1479318 <https://bugzilla.mozilla.org/show_bug.cgi?id=1479318>, Bug 1480319 <https://bugzilla.mozilla.org/show_bug.cgi?id=1480319>, Bug 1480327 <https://bugzilla.mozilla.org/show_bug.cgi?id=1480327>, Bug 1483363 <https://bugzilla.mozilla.org/show_bug.cgi?id=1483363>) - Kris also reduced memory usage by *494KB* by getting rid of MessageManager globals (Bug 1480244 <https://bugzilla.mozilla.org/show_bug.cgi?id=1480244>) - *Felipe Gomes* reduced memory usage by *95KB* by lazily loading JS content (Bug 1369466 <https://bugzilla.mozilla.org/show_bug.cgi?id=1369466>, Bug 1470324 <https://bugzilla.mozilla.org/show_bug.cgi?id=1470324>) - *Mike Kaply* reduced memory usage by *65KB* by converting an add-on to in tree telemetry (Bug 1475571 <https://bugzilla.mozilla.org/show_bug.cgi?id=1475571>) - *Dão Gottwald* reduced memory uasge by *57KB* by lazily generating thumbnails for the Ctrl+Tab panel (Bug 1481321 <https://bugzilla.mozilla.org/show_bug.cgi?id=1481321>) - *Nick Nethercote* reduced memory usage by *44KB* by making mozilla::HashMaps lazily allocate their storage (Bug 1481998 <https://bugzilla.mozilla.org/show_bug.cgi?id=1481998>) - *Benjamin Bouvier* reduced memory usage by *25KB* by removing SIMD.js (Bug 1416723 <https://bugzilla.mozilla.org/show_bug.cgi?id=1416723>) *Threading Overhead* - Kris added measurements for thread stacks across platforms (Bug 1475899 <https://bugzilla.mozilla.org/show_bug.cgi?id=1475899>, Bug 1476405 <https://bugzilla.mozilla.org/show_bug.cgi?id=1476405>, Bug 1477512) <https://bugzilla.mozilla.org/show_bug.cgi?id=1477512> - Kris reduced memory usage on Linux by *~3MB* (that's megabytes!) by changing our default stack size (Bug 1476828 <https://bugzilla.mozilla.org/show_bug.cgi?id=1476828>) - *Eric Rahm* (this author) reduced memory usage by *50KB* by reducing the amount of networking threads (Bug 1448034 <https://bugzilla.mozilla.org/show_bug.cgi?id=1448034>) - *Xidorn Quan* committed an upstream Rust patch (rust-lang/rust#52847 <https://github.com/rust-lang/rust/issues/52847>) to fix how stack sizes are set on windows after Kris' initial investigation (Bug 1479250 <https://bugzilla.mozilla.org/show_bug.cgi?id=1479250>) *Font Overhead* - The winner of biggest improvement with the smallest change goes to *Lee Salzman* who reduced memory usage on OSX by *10MB* by reducing the skia glyph cache (Bug 1258781 <https://bugzilla.mozilla.org/show_bug.cgi?id=1258781>) *Lessons learned* Small fixes add up, removing dead code not only helps code quality but can save memory, adding measurements is important, caches can be easy targets. If you know of a cache we might tweak please file a bug to consider reducing it. -e [1] https://treeherder.mozilla.org/perf.html#/graphs?timerange=2592000&series=autoland,1684872,1,4 [2] https://bugzilla.mozilla.org/show_bug.cgi?id=1476432 [3] https://bugzilla.mozilla.org/show_bug.cgi?id=1470591 [4] https://bugzilla.mozilla.org/show_bug.cgi?id=648417 _______________________________________________ dev-platform mailing list [email protected] https://lists.mozilla.org/listinfo/dev-platform
