From 86cf78d73de8c6bfa89804b91ee0ace71a459961 Mon Sep 17 00:00:00 2001 From: Sebastien Buisson Date: Thu, 9 Oct 2014 15:29:38 -0700 Subject: [PATCH] fs/buffer.c: increase the buffer-head per-CPU LRU size Increase the buffer-head per-CPU LRU size to allow efficient filesystem operations that access many blocks for each transaction. For example, creating a file in a large ext4 directory with quota enabled will access multiple buffer heads and will overflow the LRU at the default 8-block LRU size: * parent directory inode table block (ctime, nlinks for subdirs) * new inode bitmap * inode table block * 2 quota blocks * directory leaf block (not reused, but pollutes one cache entry) * 2 levels htree blocks (only one is reused, other pollutes cache) * 2 levels indirect/index blocks (only one is reused) The buffer-head per-CPU LRU size is raised to 16, as it shows in metadata performance benchmarks up to 10% gain for create, 4% for lookup and 7% for destroy. Signed-off-by: Liang Zhen Signed-off-by: Andreas Dilger Signed-off-by: Sebastien Buisson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-format-patch failed