On Tuesday, August 20, 2019 10:48:06 PM MST John Harris wrote: > 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/ I would also like to add that I don't see how it's even possible to run into a low-memory scenario on a system with 10 GiB (That's a *lot* of memory! I run on a Core 2 Duo based system that can support a max of 8 GiB as my daily driver.) often enough to have a problem with oom_killer. -- 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
