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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-04-20 18:22:15 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-06-15 01:01:42 +0200 |
| commit | 810ce8b5df1c8338065f2ae1d2ec08cc566fbb8b (patch) | |
| tree | 46d357bbd3a9cb28bc00ccce79814fdd1776bac1 /include | |
| parent | rcu: Move expedited code from tree_plugin.h to tree_exp.h (diff) | |
| download | linux-810ce8b5df1c8338065f2ae1d2ec08cc566fbb8b.tar.xz linux-810ce8b5df1c8338065f2ae1d2ec08cc566fbb8b.zip | |
rcu: Document RCU_NONIDLE() restrictions in comment header
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/rcupdate.h | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 5f1533e3d032..c61b6b9506e7 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -379,12 +379,13 @@ static inline void rcu_init_nohz(void) * in the inner idle loop. * * This macro provides the way out: RCU_NONIDLE(do_something_with_RCU()) - * will tell RCU that it needs to pay attending, invoke its argument - * (in this example, a call to the do_something_with_RCU() function), + * will tell RCU that it needs to pay attention, invoke its argument + * (in this example, calling the do_something_with_RCU() function), * and then tell RCU to go back to ignoring this CPU. It is permissible - * 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. + * to nest RCU_NONIDLE() wrappers, but not indefinitely (but the limit is + * on the order of a million or so, even on 32-bit systems). It is + * not legal to block within RCU_NONIDLE(), nor is it permissible to + * transfer control either into or out of RCU_NONIDLE()'s statement. */ #define RCU_NONIDLE(a) \ do { \ |