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author | Lai Jiangshan <laijs@cn.fujitsu.com> | 2012-11-29 16:46:09 +0800 |
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committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2013-02-07 15:19:36 -0800 |
commit | 7a6b55e7108b3476d13ee9501ec69dbe1605d774 (patch) | |
tree | 9712b0a5f7c3b5d90f2625af369774cdb1334e6f /init/do_mounts_rd.c | |
parent | 49271ca60645d64197b28c0835fed39f74b1a2d7 (diff) | |
download | op-kernel-dev-7a6b55e7108b3476d13ee9501ec69dbe1605d774.zip op-kernel-dev-7a6b55e7108b3476d13ee9501ec69dbe1605d774.tar.gz |
srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock()
The old SRCU implementation loads sp->completed within an
RCU-sched section, courtesy of preempt_disable(). This was required
due to the use of synchronize_sched() in the old implemenation's
synchronize_srcu(). However, the new implementation does not rely
on synchronize_sched(), so it in turn does not require the load of
sp->completed and the ->c[] counter to be in a single preempt-disabled
region of code. This commit therefore moves the sp->completed access
outside of the preempt-disabled region and applies ACCESS_ONCE().
The resulting code is almost as the same as before, but it removes the
now-misleading rcu_dereference_index_check() call.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'init/do_mounts_rd.c')
0 files changed, 0 insertions, 0 deletions