rcu: Fix rcu_read_unlock_strict() strict QS reporting
authorZqiang <qiang1.zhang@intel.com>
Thu, 16 Jun 2022 13:53:47 +0000 (21:53 +0800)
committerPaul E. McKenney <paulmck@kernel.org>
Wed, 31 Aug 2022 12:03:14 +0000 (05:03 -0700)
commit6d60ea03ac2d3dcf6ddee6b45aa7213d8b0461c5
tree8ba1521d2d801198d433b30e85054db9afd9799c
parent568035b01cfb107af8d2e4bd2fb9aea22cf5b868
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 <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
kernel/rcu/tree_plugin.h