Merge branch 'rcu/next' of... (1161ec94) · Commits · e / devices / android_kernel_oneplus_sm7250

init/Kconfig

+0 −15

Original line number	Diff line number	Diff line
		@@ -497,21 +497,6 @@ config RCU_BOOST_DELAY

		Accept the default if unsure.

		config SRCU_SYNCHRONIZE_DELAY
		int "Microseconds to delay before waiting for readers"
		range 0 20
		default 10
		help
		This option controls how long SRCU delays before entering its
		loop waiting on SRCU readers. The purpose of this loop is
		to avoid the unconditional context-switch penalty that would
		otherwise be incurred if there was an active SRCU reader,
		in a manner similar to adaptive locking schemes. This should
		be set to be a bit longer than the common-case SRCU read-side
		critical-section overhead.

		Accept the default if unsure.

		endmenu # "RCU Subsystem"

		config IKCONFIG

+2 −1

Original line number	Diff line number	Diff line
		@@ -189,7 +189,8 @@ static int rcu_kthread(void *arg)
		unsigned long flags;

		for (;;) {
		wait_event(rcu_kthread_wq, have_rcu_kthread_work != 0);
		wait_event_interruptible(rcu_kthread_wq,
		have_rcu_kthread_work != 0);
		morework = rcu_boost();
		local_irq_save(flags);
		work = have_rcu_kthread_work;

+13 −2

Original line number	Diff line number	Diff line
		@@ -155,6 +155,16 @@ void __srcu_read_unlock(struct srcu_struct *sp, int idx)
		}
		EXPORT_SYMBOL_GPL(__srcu_read_unlock);

		/*
		* We use an adaptive strategy for synchronize_srcu() and especially for
		* synchronize_srcu_expedited(). We spin for a fixed time period
		* (defined below) to allow SRCU readers to exit their read-side critical
		* sections. If there are still some readers after 10 microseconds,
		* we repeatedly block for 1-millisecond time periods. This approach
		* has done well in testing, so there is no need for a config parameter.
		*/
		#define SYNCHRONIZE_SRCU_READER_DELAY 10

		/*
		* Helper function for synchronize_srcu() and synchronize_srcu_expedited().
		*/
		@@ -207,11 +217,12 @@ static void __synchronize_srcu(struct srcu_struct sp, void (sync_func)(void))
		* will have finished executing. We initially give readers
		* an arbitrarily chosen 10 microseconds to get out of their
		* SRCU read-side critical sections, then loop waiting 1/HZ
		* seconds per iteration.
		* seconds per iteration. The 10-microsecond value has done
		* very well in testing.
		*/

		if (srcu_readers_active_idx(sp, idx))
		udelay(CONFIG_SRCU_SYNCHRONIZE_DELAY);
		udelay(SYNCHRONIZE_SRCU_READER_DELAY);
		while (srcu_readers_active_idx(sp, idx))
		schedule_timeout_interruptible(1);