ext4: don't lock the next page in write_cache_pages if not needed
authorTheodore Ts'o <tytso@mit.edu>
Sat, 26 Feb 2011 19:09:14 +0000 (14:09 -0500)
committerTheodore Ts'o <tytso@mit.edu>
Sat, 26 Feb 2011 19:09:14 +0000 (14:09 -0500)
commit78aaced3408141bb7c836f2db0ca435790399da5
treec761d397605095d4d895ede9fc5e6a6548723cad
parentee6ecbcc5d73672217fdea420d182ecb0cdf310c
ext4: don't lock the next page in write_cache_pages if not needed

If we have accumulated a contiguous region of memory to be written
out, and the next page can added to this region, don't bother locking
(and then unlocking the page) before writing out the memory.  In the
unlikely event that the next page was being written back by some other
CPU, we can also skip waiting that page to finish writeback.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
fs/ext4/inode.c