On Thu, Feb 20, 2020 at 12:45 PM Luigi Semenzato <semenzato@xxxxxxxxxx> wrote: > > On Thu, Feb 20, 2020 at 11:09 AM Chris Murphy <lists@xxxxxxxxxxxxxxxxx> wrote: > > > > On Thu, Feb 20, 2020 at 10:16 AM Luigi Semenzato <semenzato@xxxxxxxxxx> wrote: > > > > > > I think this is the right group for the memory issues. > > > > > > I suspect that the problem with failed allocations (ENOMEM) boils down > > > to the unreliability of the page allocator. In my experience, under > > > pressure (i.e. pages must be swapped out to be reclaimed) allocations > > > can fail even when in theory they should succeed. (I wish I were > > > wrong and that someone would convincingly correct me.) > > > > What is vm.swappiness set to on your system? A fellow Fedora > > contributor who has consistently reproduced what you describe, has > > discovered he has vm.swappiness=0, and even if it's set to 1, the > > problem no longer happens. And this is not a documented consequence of > > using a value of 0. > > I am using the default value of 60. > > A zero value should cause all file pages to be discarded before any > anonymous pages are swapped. I wonder if the fellow Fedora > contributor's workload has a lot of file pages, so that discarding > them is enough for the image allocator to succeed. In that case "sync; > echo 1 > /proc/sys/vm/drop_caches" would be a better way of achieving > the same result. (By the way, in my experiments I do that just before > hibernating.) He reports hibernation failure even if he drops caches beforehand. https://lists.fedoraproject.org/archives/list/desktop@xxxxxxxxxxxxxxxxxxxxxxx/message/XYWYF33RFVISVZTPYSJRRXP7TFXPV4GD/ -- Chris Murphy
