Bug#702477: moreinfo

[Dmitry Smirnov <onlyjob@member.fsf.org>]

I found that dropping dentries and inode caches with

	sudo su -c 'echo 2 > /proc/sys/vm/drop_caches'

is helpful to avoid performance degradation if given before each tree walk 
probably because it drops nfs_inode_cache.
However I don't understand why dropping pagecache by

	sudo su -c 'echo 1 > /proc/sys/vm/drop_caches'

helps in this situation as well...