From 710585d4922fd315f2cada8fbe550ae8ed23e994 Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Wed, 10 Dec 2014 15:45:01 -0800 Subject: fs/proc: use a rb tree for the directory entries When a lot of netdevices are created, one of the bottleneck is the creation of proc entries. This serie aims to accelerate this part. The current implementation for the directories in /proc is using a single linked list. This is slow when handling directories with large numbers of entries (eg netdevice-related entries when lots of tunnels are opened). This patch replaces this linked list by a red-black tree. Here are some numbers: dummy30000.batch contains 30 000 times 'link add type dummy'. Before the patch: $ time ip -b dummy30000.batch real 2m31.950s user 0m0.440s sys 2m21.440s $ time rmmod dummy real 1m35.764s user 0m0.000s sys 1m24.088s After the patch: $ time ip -b dummy30000.batch real 2m0.874s user 0m0.448s sys 1m49.720s $ time rmmod dummy real 1m13.988s user 0m0.000s sys 1m1.008s The idea of improving this part was suggested by Thierry Herbelot. [akpm@linux-foundation.org: initialise proc_root.subdir at compile time] Signed-off-by: Nicolas Dichtel Acked-by: David S. Miller Cc: Thierry Herbelot . Acked-by: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/root.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/proc/root.c') diff --git a/fs/proc/root.c b/fs/proc/root.c index 094e44d4a6be..e74ac9f1a2c0 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -251,6 +251,7 @@ struct proc_dir_entry proc_root = { .proc_iops = &proc_root_inode_operations, .proc_fops = &proc_root_operations, .parent = &proc_root, + .subdir = RB_ROOT, .name = "/proc", }; -- cgit v1.2.3