From 4c55f4f9ad3001ac1fefdd8d8ca7641d18558e23 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 18 Aug 2015 14:55:09 -0700 Subject: blkcg: restructure blkg_policy_data allocation in blkcg_activate_policy() When a policy gets activated, it needs to allocate and install its policy data on all existing blkg's (blkcg_gq's). Because blkg iteration is protected by a spinlock, it currently counts the total number of blkg's in the system, allocates the matching number of policy data on a list and installs them during a single iteration. This can be simplified by using speculative GFP_NOWAIT allocations while iterating and falling back to a preallocated policy data on failure. If the preallocated one has already been consumed, it releases the lock, preallocate with GFP_KERNEL and then restarts the iteration. This can be a bit more expensive than before but policy activation is a very cold path and shouldn't matter. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- include/linux/blk-cgroup.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'include') diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 9711fc277c02..db822880242a 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -80,9 +80,6 @@ struct blkg_policy_data { /* the blkg and policy id this per-policy data belongs to */ struct blkcg_gq *blkg; int plid; - - /* used during policy activation */ - struct list_head alloc_node; }; /* -- cgit