At Fri, 24 Apr 2020 14:56:37 +0200, tlaronde%polynum.com@localhost wrote: Subject: Re: Linux compat and swap > > Does somebody know what are the main source files implementing it so > that if no in depth documentation is available, the C files would give > the picture? again, from my sysctl.conf: :-) # See also: # # http://web.archive.org/web/20181008110324/http://www.selonen.org/arto/netbsd/vm_tune.html # http://chuck.cranor.org/p/diss.pdf # http://usenix.org/publications/library/proceedings/usenix99/full_papers/cranor/cranor.pdf BTW, I've used the settings I posted basically since UVM was integrated on all my servers, and even on some small machines like a little Soekris board with 512MB of RAM. In hindsight I think the vm.exec* values are a bit too high for most uses, but at the same time they don't seem to hurt for the kinds of uses I put my machines to. I admit though I haven't extremely stressed any smaller machines (virtual or otherwise) to see how they do. The domU I edit/email/build on has 8GB assigned, and though it runs with a fair number of pages out on swap, it never thrashes even with "-j 12" builds. (and that's with a fully static-linked userland too) I would say generally speaking that UVM does better than any other VM management system I've used, including even macOS with its compressed memory feature; though at some level macOS is hard to judge because of its massive overreliance on dynamic linking and zillions of frameworks. macOS only really starts to shine on 2+ CPU machines with SSD system storage. Indeed I suspect adding compressed memory support to UVM, i.e. as an intermediate step before paging to disk, could make it the very best of the best (for multi-core SMP systems, at least, though even a single CPU can probably swap compressed pages faster than it can write and read them from spinning rust). -- Greg A. Woods <gwoods%acm.org@localhost> Kelowna, BC +1 250 762-7675 RoboHack <woods%robohack.ca@localhost> Planix, Inc. <woods%planix.com@localhost> Avoncote Farms <woods%avoncote.ca@localhost>
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