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author | Tejun Heo <tj@kernel.org> | 2013-05-14 20:52:31 (GMT) |
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committer | Tejun Heo <tj@kernel.org> | 2013-05-14 20:52:31 (GMT) |
commit | 2a4fd070ee8561d918a3776388331bb7e92ea59e (patch) | |
tree | 53eb9c6df1ea0e02cb3f3442fb85f9e25a4691ed /block/blk-throttle.c | |
parent | db61367038dcd222476881cb09fd54661b3cd508 (diff) | |
download | linux-fsl-qoriq-2a4fd070ee8561d918a3776388331bb7e92ea59e.tar.xz |
blkcg: move bulk of blkcg_gq release operations to the RCU callback
Currently, when the last reference of a blkcg_gq is put, all then
release operations sans the actual freeing happen directly in
blkg_put(). As blkg_put() may be called under queue_lock, all
pd_exit_fn()s may be too. This makes it impossible for pd_exit_fn()s
to use del_timer_sync() on timers which grab the queue_lock which is
an irq-safe lock due to the deadlock possibility described in the
comment on top of del_timer_sync().
This can be easily avoided by perfoming the release operations in the
RCU callback instead of directly from blkg_put(). This patch moves
the blkcg_gq release operations to the RCU callback.
As this leaves __blkg_release() with only call_rcu() invocation,
blkg_rcu_free() is renamed to __blkg_release_rcu(), exported and
call_rcu() invocation is now done directly from blkg_put() instead of
going through __blkg_release() which is removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Diffstat (limited to 'block/blk-throttle.c')
0 files changed, 0 insertions, 0 deletions