ext4: optimize ext4_es_shrink()
authorTheodore Ts'o <tytso@mit.edu>
Fri, 1 Mar 2013 04:58:56 +0000 (23:58 -0500)
committerTheodore Ts'o <tytso@mit.edu>
Fri, 1 Mar 2013 04:58:56 +0000 (23:58 -0500)
commit246307745c406379996e6ed6411f0e20f1ce1449
tree71b78d765ba7406c6755cad807944da6a99e5980
parent8e919d13048cd5acaadb2b15b48acbfb8832d3c2
ext4: optimize ext4_es_shrink()

When the system is under memory pressure, ext4_es_srhink() will get
called very often.  So optimize returning the number of items in the
file system's extent status cache by keeping a per-filesystem count,
instead of calculating it each time by scanning all of the inodes in
the extent status cache.

Also rename the slab used for the extent status cache to be
"ext4_extent_status" so it's obviousl the slab in question is created
by ext4.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Zheng Liu <gnehzuil.liu@gmail.com>
fs/ext4/ext4.h
fs/ext4/extents_status.c
include/trace/events/ext4.h