From: Zqiang Date: Thu, 16 Jun 2022 13:53:47 +0000 (+0800) Subject: rcu: Fix rcu_read_unlock_strict() strict QS reporting X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6d60ea03ac2d3dcf6ddee6b45aa7213d8b0461c5;p=linux.git rcu: Fix rcu_read_unlock_strict() strict QS reporting Kernels built with CONFIG_PREEMPT=n and CONFIG_RCU_STRICT_GRACE_PERIOD=y report the quiescent state directly from the outermost rcu_read_unlock(). However, the current CPU's rcu_data structure's ->cpu_no_qs.b.norm might still be set, in which case rcu_report_qs_rdp() will exit early, thus failing to report quiescent state. This commit therefore causes rcu_read_unlock_strict() to clear CPU's rcu_data structure's ->cpu_no_qs.b.norm field before invoking rcu_report_qs_rdp(). Signed-off-by: Zqiang Signed-off-by: Paul E. McKenney --- diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 438ecae6bd7e7..86772c95ed0ae 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -824,6 +824,7 @@ void rcu_read_unlock_strict(void) if (irqs_disabled() || preempt_count() || !rcu_state.gp_kthread) return; rdp = this_cpu_ptr(&rcu_data); + rdp->cpu_no_qs.b.norm = false; rcu_report_qs_rdp(rdp); udelay(rcu_unlock_delay); }