Because SRCU-fast does not need quiescent-state helpers, this commit removes rcu_tasks_trace_qs() and those things that only it uses, including rcu_trc_cmpxchg_need_qs(), TRC_NEED_QS, and TRC_NEED_QS_CHECKED.
Signed-off-by: Paul E. McKenney <[email protected]> Cc: Andrii Nakryiko <[email protected]> Cc: Alexei Starovoitov <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: <[email protected]> --- include/linux/rcupdate.h | 26 +------------------------- kernel/rcu/tasks.h | 12 ------------ 2 files changed, 1 insertion(+), 37 deletions(-) diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 120536f4c6eb1d..879525c5764a0c 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -176,35 +176,11 @@ void rcu_tasks_torture_stats_print(char *tt, char *tf); # endif # ifdef CONFIG_TASKS_TRACE_RCU -// Bits for ->trc_reader_special.b.need_qs field. -#define TRC_NEED_QS 0x1 // Task needs a quiescent state. -#define TRC_NEED_QS_CHECKED 0x2 // Task has been checked for needing quiescent state. - -u8 rcu_trc_cmpxchg_need_qs(struct task_struct *t, u8 old, u8 new); void rcu_tasks_trace_qs_blkd(struct task_struct *t); - -# define rcu_tasks_trace_qs(t) \ - do { \ - int ___rttq_nesting = READ_ONCE((t)->trc_reader_nesting); \ - \ - if (unlikely(READ_ONCE((t)->trc_reader_special.b.need_qs) == TRC_NEED_QS) && \ - likely(!___rttq_nesting)) { \ - rcu_trc_cmpxchg_need_qs((t), TRC_NEED_QS, TRC_NEED_QS_CHECKED); \ - } else if (___rttq_nesting && ___rttq_nesting != INT_MIN && \ - !READ_ONCE((t)->trc_reader_special.b.blocked)) { \ - rcu_tasks_trace_qs_blkd(t); \ - } \ - } while (0) void rcu_tasks_trace_torture_stats_print(char *tt, char *tf); -# else -# define rcu_tasks_trace_qs(t) do { } while (0) # endif -#define rcu_tasks_qs(t, preempt) \ -do { \ - rcu_tasks_classic_qs((t), (preempt)); \ - rcu_tasks_trace_qs(t); \ -} while (0) +#define rcu_tasks_qs(t, preempt) do { rcu_tasks_classic_qs((t), (preempt)); } while (0) # ifdef CONFIG_TASKS_RUDE_RCU void synchronize_rcu_tasks_rude(void); diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index 418fa242cf0288..967c43b1937bae 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -1471,18 +1471,6 @@ void __init rcu_tasks_trace_suppress_unused(void) rcu_tasks_torture_stats_print_generic(NULL, NULL, NULL, NULL); } -/* - * Do a cmpxchg() on ->trc_reader_special.b.need_qs, allowing for - * the four-byte operand-size restriction of some platforms. - * - * Returns the old value, which is often ignored. - */ -u8 rcu_trc_cmpxchg_need_qs(struct task_struct *t, u8 old, u8 new) -{ - return cmpxchg(&t->trc_reader_special.b.need_qs, old, new); -} -EXPORT_SYMBOL_GPL(rcu_trc_cmpxchg_need_qs); - /* Add a newly blocked reader task to its CPU's list. */ void rcu_tasks_trace_qs_blkd(struct task_struct *t) { -- 2.40.1
