Martin Knoblauch wrote: > ----- Original Message ---- > > >> >> I think having a tunable for client readahead is an excellent idea, >> although not to solve your particular problem. The SLES10 kernel has a >> patch which does precisely that, perhaps Neil could post it. >> >> I don't think there's a lot of point having both a module parameter and >> a sysctl. >> >> > > Actually there is a good reason. The module parameter can be used to set the new value at load time and never bother again. The sysctl is very convenient when doing experiments. > You can set module parameters after module load in /sys/module/$module/parameters. > As Andrew already pointed out, the best solution would be a mount option. Yep. > But that seems much more involved as my workaround patch. > > Yep. >> A maximum of 15 is unwise. I've found that (at least with the older >> readahead mechanisms in SLES10) a multiple of 4 is required to preserve >> rsize-alignment of READ rpcs to the server, which helps a lot with wide >> RAID backends. So in SGI we tune client readahead to 16. >> >> > > 15 is the value that the Linux NFS client uses., at least since 2.6.3. It's a silly value. > As it is not tunable up to today, the comment seems moot :-) But it opens the questions: > > a) should 1 be the minimum, or 0? > Turning off client RA entirely is potentially useful. > b) can the backing_dev_info.ra_pages field safely be set to something higher than 15? > Yes. Did I mention 16 ? > >> Your patch seems to have a bunch of other unrelated stuff mixed in. >> >> > > Yeah, someone already pointed out, that the Makefile hunk does not belong there. But you say "a bunch" - anything else? > I rapidly scrolled past some stuff about 64bit inodes. > Cheers > Martin > PS: Did we ever meet/mail when I was at SGI (1991-1997)? > > I'm more recent than that. -- Greg Banks, P.Engineer, SGI Australian Software Group. Be like the squirrel. I don't speak for SGI. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
