Hi list, there's that recent interesting addition to linux: `cleancache' (and `zcache'). I've enabled it for NILFS2 yesterday (in 3.0-rc2). It seemed to work for a while -- sensible numbers in /sys/kernel/mm/cleancache/* But it broke terribly after performing echo 3 > /proc/sys/vm/drop_caches kernel reported NULL pointer dereference, IIRC. Ext4 works a-OK with that, so my first guess waws NILFS2 is doing something funky with page allocation or mapping. Cleancache has own hooks into VFS, and for `normal' filesystem that's enough; at least enough for ext3 and ext4 drivers to work reliably. On the other hand, btrfs does something unusual with pages and they used extra cleancache hooks for btrfs, IIRC. Should I dig further, post backtraces or something? I believe using cleancache + zcache could be beneficial, especially for NILFS2 metadata like the DAT file; what are your thoughts on it? Regards, -- dexen deVries [[[â][â]]] For example, if the first thing in the file is: <?kzy irefvba="1.0" rapbqvat="ebg13"?> an XML parser will recognize that the document is stored in the traditional ROT13 encoding. (( Joe English, http://www.flightlab.com/~joe/sgml/faq-not.txt )) -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
