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context_tracking: Remove rcu_task_trace_heavyweight_{enter,exit}()

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Because SRCU-fast does not use IPIs for its grace periods, there is
no need for real-time workloads to switch to an IPI-free mode, and
there is in turn no need for either rcu_task_trace_heavyweight_enter()
or rcu_task_trace_heavyweight_exit().  This commit therefore removes them.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: bpf@vger.kernel.org
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
This commit is contained in:
Paul E. McKenney 2025-12-29 11:10:57 -08:00 • committed by Boqun Feng
parent c27cea4416
commit 46e3235999
1 changed files with 0 additions and 20 deletions
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20
kernel/context_tracking.c
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@ -54,24 +54,6 @@ static __always_inline void rcu_task_enter(void)
#endif /* #if defined(CONFIG_TASKS_RCU) && defined(CONFIG_NO_HZ_FULL) */
}
/* Turn on heavyweight RCU tasks trace readers on kernel exit. */
static __always_inline void rcu_task_trace_heavyweight_enter(void)
{
#ifdef CONFIG_TASKS_TRACE_RCU
if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB))
current->trc_reader_special.b.need_mb = true;
#endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
}
/* Turn off heavyweight RCU tasks trace readers on kernel entry. */
static __always_inline void rcu_task_trace_heavyweight_exit(void)
{
#ifdef CONFIG_TASKS_TRACE_RCU
if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB))
current->trc_reader_special.b.need_mb = false;
#endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
}
/*
* Record entry into an extended quiescent state. This is only to be
* called when not already in an extended quiescent state, that is,
@ -85,7 +67,6 @@ static noinstr void ct_kernel_exit_state(int offset)
* critical sections, and we also must force ordering with the
* next idle sojourn.
*/
rcu_task_trace_heavyweight_enter(); // Before CT state update!
// RCU is still watching. Better not be in extended quiescent state!
WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !rcu_is_watching_curr_cpu());
(void)ct_state_inc(offset);
@ -108,7 +89,6 @@ static noinstr void ct_kernel_enter_state(int offset)
*/
seq = ct_state_inc(offset);
// RCU is now watching. Better not be in an extended quiescent state!
rcu_task_trace_heavyweight_exit(); // After CT state update!
WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !(seq & CT_RCU_WATCHING));
}