Date: Sun, 4 Mar 2018 11:51:39 -0800 From: Mark Millard <marklmi26-fbsd@yahoo.com> To: Freebsd-arm <freebsd-arm@freebsd.org> Subject: Re: Is maximum swap usage tunable? Message-ID: <1EB91943-C141-4EA6-AD63-A629525E206E@yahoo.com>
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bob prohaska fbsd at www.zefox.net write on Sun Mar 4 18:28:36 UTC 2018: > The worst-case events were > dT: 10.002s w: 10.000s > L(q) ops/s r/s kBps ms/r w/s kBps ms/w %busy Name > . . . > 0 1 0 13 5.6 1 28 5674 88.3 da0b > . . . I'll note that (1000s/ms)*(ms/w) != 1/(w/s) here (and frequently). (ms/r and r/s are similarly related.) It appears that ms/w counts time with the write waiting in a queue to be executed or some such but w/s is strictly the observed rate of writes happening, independent of how long each waited. (The columns need not refer to the exact same time frame either as far as I can tell.) [Someone may know the actual details of what ms/w and ms/r spans. The above includes guess work.] Also: 5674 ms/w is over 5 seconds "per write" (probably a "mean" form of average, but possibly only one write covered). I doubt that we can be sure of much about the stages involved in that large figure if "time waiting in the queue" and later stages of the processing all contribute. === Mark Millard marklmi at yahoo.com ( markmi at dsl-only.net is going away in 2018-Feb, late)
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