On Wed, 8 Jun 2011 15:14:59 +0200, dexen deVries wrote: > 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? Interesting. Can you get a log of the oops ? I may have time to look into the problem in this weekend. Regards, Ryusuke Konishi > 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 > > [[[↓][→]]] > > 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 -- 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
