Nathaniel Smith writes: > On Fri, Jul 28, 2006 at 11:58:29AM -0700, Eric Anderson wrote: > > avg resident size has decreased from 4.35 to 3.1 > > MiB, avg size has decreased from 21.4 MiB to 19.8 MiB. Similar on the > > maximum values. The only odd thing is that all three "after" runs > > took way more wall clock time, but similar system and user time. > > Hrm, weird -- I actually re-ran these when writing the email, since > I'd deleted my first run, and I could swear the numbers were weirder > before :-). (Weirder, like, swap the average resident sizes between > the two runs.) I still have some trouble interpreting these -- why are > the max-resident sizes the same?
I would imagine because there is some point in time where both processes have the same resident size; it could be at the beginning Botan does a remarkable amount of self-testing on every run. > I would have thought that was the > most interesting number, since peak memory usage is often more > important than average memory usage, and the total (as opposed to > resident) numbers are clearly counting, like, the size of all linked > libraries or something. > Probably I/we just need more experience in interpreting these numbers; > they're a little trickier to understand than I expected. (It might > still be interesting to add an instrumenter that hooks into malloc and > gives peak _heap_ amounts in particular, just because those are > presumably less noisy and easier to interpret in terms of code.) The memtime program is doing sampling of the values in /proc to figure out how much memory is used at any particular time. This means that it can miss very short peaks. In general I ignore differences of < 10%, so would have considered the two runs you had to be pretty much the same, even though there is a valid statistical difference on both the avg-{resident,size} and max-size. That said a resident size of <10MB is pretty much nothing. -Eric _______________________________________________ Monotone-devel mailing list Monotone-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/monotone-devel