2012/1/23 Edward Tomasz Napierała <[email protected]>: > Some time ago I've spent some time on trying to speed up loading > modules by the loader(8). Result can be found at: > > http://people.freebsd.org/~trasz/fast-loader-3.diff > > This patch solves three issues: > > 1. As it is now, the code in biosdisk.c tries very hard to split > reasonably sized (up to 64kB, IIRC) requests into smaller ones. > > 2. The code in biosdisk.c rereads the partition table and probably > some filesystem metadata every time a file gets opened, i.e. > for every module. These reads bypass the bcache. > > 3. The code in bcache.c doesn't really implement an LRU - it implements > 'least recently added' algorithm, i.e. a kind of queue. Not that > it matters much, since it flushes the elements two seconds after > caching them anyway. I replaced it with Least Frequently Used. > LRU didn't behave well, as it tended to replace metadata with data > used only once.
4. it flushes cache on access to a different drive which means that cache does not help on multi-disk ZFS setups. I've posted a patch some time back. See http://lists.freebsd.org/pipermail/freebsd-fs/2011-September/012527.html Feel free to combine the changes. --Artem > > In my tests under VMWare Fusion, this cut the modules loading time > by half. I don't intend to commit the patch as-is - the first part > looks dangerous (the splitting was probably done for a reason), > the second is hackish, and the third doesn't improve anything by itself. > I'm working on something else at a moment; feel free to pick this up. > > -- > If you cut off my head, what would I say? Me and my head, or me and my body? > _______________________________________________ > [email protected] mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "[email protected]" _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[email protected]"
