diff options
author | Tejun Heo <tj@kernel.org> | 2015-08-18 14:55:09 -0700 |
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committer | Jens Axboe <axboe@fb.com> | 2015-08-18 15:49:16 -0700 |
commit | 4c55f4f9ad3001ac1fefdd8d8ca7641d18558e23 (patch) | |
tree | 66be4a0f4881ba200b7e31e9f0efac8912ab0f21 /net/nfc/nci | |
parent | bc915e61cde25d0b429f536cec9e83039bf23504 (diff) |
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 <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'net/nfc/nci')
0 files changed, 0 insertions, 0 deletions