Date: Sat, 26 Mar 2016 14:26:45 -0700 (PDT) From: Don Lewis <truckman@FreeBSD.org> To: imb@protected-networks.net Cc: ohartman@zedat.fu-berlin.de, kmacy@freebsd.org, freebsd-current@freebsd.org Subject: Re: CURRENT slow and shaky network stability Message-ID: <201603262126.u2QLQjT0079960@gw.catspoiler.org> In-Reply-To: <56F6C6B0.6010103@protected-networks.net>
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On 26 Mar, Michael Butler wrote: > -current is not great for interactive use at all. The strategy of > pre-emptively dropping idle processes to swap is hurting .. big time. > > Compare inactive memory to swap in this example .. > > 110 processes: 1 running, 108 sleeping, 1 zombie > CPU: 1.2% user, 0.0% nice, 4.3% system, 0.0% interrupt, 94.5% idle > Mem: 474M Active, 1609M Inact, 764M Wired, 281M Buf, 119M Free > Swap: 4096M Total, 917M Used, 3178M Free, 22% Inuse > > PID USERNAME THR PRI NICE SIZE RES STATE C TIME WCPU > COMMAND > 1819 imb 1 28 0 213M 11284K select 1 147:44 5.97% > gkrellm > 59238 imb 43 20 0 980M 424M select 0 10:07 1.92% > firefox > > .. it shouldn't start randomly swapping out processes because they're > used infrequently when there's more than enough RAM to spare .. I don't know what changed, and probably something can use some tweaking, but paging out idle processes isn't always the wrong thing to do. For instance if I'm using poudriere to build a bunch of packages and its heavy use of tmpfs is pushing the machine into many GB of swap usage, I don't want interactive use like: vi foo.c cc foo.c vi foo.c to suffer because vi and cc have to be read in from a busy hard drive each time while unused console getty and idle sshd processes in a bunch of jails are still hanging on to memory even though they haven't executed any instructions since shortly after the machine was booted weeks ago. > It also shows up when trying to reboot .. on all of my gear, 90 seconds > of "fail-safe" time-out is no longer enough when a good proportion of > daemons have been dropped onto swap and must be brought back in to flush > their data segments :-( That's a different and known problem. See: <https://svnweb.freebsd.org/base/releng/10.3/bin/csh/config_p.h?revision=297204&view=markup>;
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