On Sat, 2006-Mar-25 09:20:13 -0500, Mikhail Teterin wrote: >I'm sorry, that should be http://aldan.algebra.com/~mi/mzip.c -- I checked >this time :-(
It doesn't look like it's doing anything especially weird. As Matt pointed out, creating files with mmap() is not a good idea because the syncer can cause massive fragmentation when allocating space. I can't test is as-is because it insists on mmap'ing its output and I only have one disk and you can't mmap /dev/null. Since your program is already written to mmap the input and output in pieces, it would be trivial to convert it to use read/write. >= I tried writing a program that just mmap'd my entire (2GB) test file >= and summed all the longwords in it. > >The files I'm dealing with are database dumps -- 10-80Gb :-) Maybe, that's, >what triggers some pessimal case?.. I tried generating an 11GB test file and got results consistent with my previous tests: grep using read or mmap, as well as mmap'ing the entire file give similar times with the disk mostly saturated. I suggest you try converting mzip.c to use read/write and see if the problem is still present. -- Peter Jeremy _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
