Am Freitag, 21. Dezember 2007 13:23:49 schrieb David Cournapeau: > > Instead of saying "memmap is ALL about disc access" I would rather > > like to say that "memap is all about SMART disk access" -- what I mean > > is that memmap should run as fast as a normal ndarray if it works on > > the cached part of an array. Maybe there is a way of telling memmap > > when and what to cache and when to sync that cache to the disk. > > In other words, memmap should perform just like a in-pysical-memory > > array -- only that it once-in-a-while saves/load to/from the disk. > > Or is this just wishful thinking ? > > Is there a way of "pre loading" a given part into cache > > (pysical-memory) or prevent disc writes at "bad times" ? > > How about doing the sync from a different thread ;-) > > mmap is using the OS IO caches, that's kind of the point of using mmap > (at least in this case). Instead of doing the caching yourself, the OS > does it for you, and OS are supposed to be smart about this :)
AFAICS this is what Sebastian wanted to say, but as the OP indicated, preloading e.g. by reading the whole array once did not work for him. Thus, I understand Sebastian's questions as "is it possible to help the OS when it is not smart enough?". Maybe something along the lines of mlock, only not quite as aggressive. Ciao, / / /--/ / / ANS _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion