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| author | Paul E. McKenney <paul.mckenney@linaro.org> | 2012-07-31 10:12:48 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-09-23 07:42:49 -0700 |
| commit | b4270ee356e5ecef5394ab80c0a0301c1676b7f0 (patch) | |
| tree | d600c6dcea20363414220b9b369832af97a8a090 /include/linux/rcupdate.h | |
| parent | 1e3fd2b38cea41f5386bf23440f2cbdd74cf13d0 (diff) | |
| download | lwn-b4270ee356e5ecef5394ab80c0a0301c1676b7f0.tar.gz lwn-b4270ee356e5ecef5394ab80c0a0301c1676b7f0.zip | |
rcu: Permit RCU_NONIDLE() to be used from interrupt context
There is a need to use RCU from interrupt context, but either before
rcu_irq_enter() is called or after rcu_irq_exit() is called. If the
interrupt occurs from idle, then lockdep-RCU will complain about such
uses, as they appear to be illegal uses of RCU from the idle loop.
In other environments, RCU_NONIDLE() could be used to properly protect
the use of RCU, but RCU_NONIDLE() currently cannot be invoked except
from process context.
This commit therefore modifies RCU_NONIDLE() to permit its use more
globally.
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'include/linux/rcupdate.h')
| -rw-r--r-- | include/linux/rcupdate.h | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 115ead2b5155..0fbbd52e01f9 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -210,14 +210,12 @@ extern void exit_rcu(void); * to nest RCU_NONIDLE() wrappers, but the nesting level is currently * quite limited. If deeper nesting is required, it will be necessary * to adjust DYNTICK_TASK_NESTING_VALUE accordingly. - * - * This macro may be used from process-level code only. */ #define RCU_NONIDLE(a) \ do { \ - rcu_idle_exit(); \ + rcu_irq_enter(); \ do { a; } while (0); \ - rcu_idle_enter(); \ + rcu_irq_exit(); \ } while (0) /* |