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author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2018-04-25 13:01:25 -0700 |
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committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2018-11-08 21:54:14 -0800 |
commit | 0607ba8403c4cdb253f8c5200ecf654dfb7790cc (patch) | |
tree | 1c980c7df600c90717f87172df7d9259a233a87a /firmware | |
parent | f3e763c3e544b73ae5c4a3842cedb9ff6ca37715 (diff) |
srcu: Prevent __call_srcu() counter wrap with read-side critical section
Ever since cdf7abc4610a ("srcu: Allow use of Tiny/Tree SRCU from
both process and interrupt context"), it has been permissible
to use SRCU read-side critical sections in interrupt context.
This allows __call_srcu() to use SRCU read-side critical sections to
prevent a new SRCU grace period from ending before the call to either
srcu_funnel_gp_start() or srcu_funnel_exp_start completes, thus preventing
SRCU grace-period counter overflow during that time.
Note that this does not permit removal of the counter-wrap checks in
srcu_gp_end(). These check are necessary to handle the case where
a given CPU does not interact at all with SRCU for an extended time
period.
This commit therefore adds an SRCU read-side critical section to
__call_srcu() in order to prevent grace period counter wrap during
the funnel-locking process.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'firmware')
0 files changed, 0 insertions, 0 deletions