On Sunday, August 18, 2019 4:33:47 AM MST Gordan Bobic wrote: > On Sun, Aug 11, 2019 at 10:36 AM <mcatanzaro(a)gnome.org> wrote: > > This seems like a distraction from the real goal here, which is to > > ensure Fedora remains responsive under heavy memory pressure, > > I think this is an overwhelmingly important point, and as somebody > regularly working with ARM machines with tiny amounts of RAM, it is of > considerable interest to me. > I typically use CentOS because stability is important to me, but most > worthwhile things filter to there, so I hope what I'm about to say is not > _too_ deprecated. > > 1) Compile options > From what I can tell from rpm macro options, default on C7 seems to be -O2. > -Os seems to help in most cases. > Adding -ffunction-sections -fdata-sections to defaults can help > considerably in producing smaller binaries, and is not the default. > Linking with -Wl,--gc-sections helps a lot and is not the default > Extensive stripping seems to already be the default (--strip-unneeded, > removal of .comment and .note sections) > > 2) Runtime condiguration > Default stack size is 8192 (ulimit -s). This unnecessarily eats a > considerably amount of memory. I have yet to see anything that actually > experiences problems with 1M. > > 3) zram > This was mentioned earlier in the thread, and on most of my systems, memory > constrained or otherwise, unless I have an overwhelming reason not to, I > run with zram swap equal in size to RAM with lz4 compression and > vm.swappiness=100. I typically see compression ratios between 2:1 and 3:1 > in zram, so on a system with, say, 10GB of RAM, it would provide 10GB of > very fast swap at a cost of 3-5GB of RAM. This seems like a favourable > trade off, especially on systems with extremely constrained RAM (e.g. ARM > devices with 512MB of RAM). > > I'm sure there is more that can be done, but this seems like a good start > as far as the cost / benefit is concerned. Python, Lua and a few other common programs can have issues with a stack size of 1MiB. -- John M. Harris, Jr. <johnmh@xxxxxxxxxxxxx> Splentity https://splentity.com/ _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
