2010/8/17 Dimitry Andric <dimi...@andric.com> > On 2010-08-16 10:55, Dag-Erling Smørgrav wrote: > > Dimitry Andric <dimi...@andric.com> writes: > >> - Uses plain file descriptors instead of struct FILE, since the > >> buffering is done manually anyway, and it makes it easier to support > >> gzip and bzip2. > > It might be worth a shot adding mmap(2) support as well, i.e. when > > processing an uncompressed regular file, try to mmap(2) it first, and if > > that fails, fall back to the plain buffered read(2) method. > > I added a simple mmap to grep, and time-trialed it, but the mmap version > was somewhat slower than the regular version. I understood from Kostik > Belousov that readahead does not work properly with mmap, and it should > not be used for "one-time" reads. > >
Try it again on a memory resident file with the MAP_PREFAULT_READ option that is provided by this patch: http://www.cs.rice.edu/~alc/MAP_PREFAULT_READ.patch Regards, Alan _______________________________________________ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
