Commit f74126dc authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcu: Make rcu_gp_init() and rcu_gp_fqs_loop noinline to conserve stack 



The kbuild test project found an oversized stack frame in rcu_gp_kthread()
for some kernel configurations.  This oversizing was due to a very large
amount of inlining, which is unnecessary due to the fact that this code
executes infrequently.  This commit therefore marks rcu_gp_init() and
rcu_gp_fqs_loop noinline_for_stack to conserve stack space.

Reported-by: default avatarkernel test robot <lkp@intel.com>
Tested-by: default avatarRong Chen <rong.a.chen@intel.com>
[ paulmck: noinline_for_stack per Nathan Chancellor. ]
Reviewed-by: default avatarNathan Chancellor <nathan@kernel.org>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent d9ee962f

kernel/rcu/tree.c

+2 −2
Original line number Original line Diff line number Diff line
@@ -1733,7 +1733,7 @@ static void rcu_strict_gp_boundary(void *unused) 
/*

/*

 * Initialize a new grace period.  Return false if no grace period required.

 * Initialize a new grace period.  Return false if no grace period required.

 */

 */

static bool rcu_gp_init(void)

static noinline_for_stack bool rcu_gp_init(void)

{

{

	unsigned long firstseq;

	unsigned long firstseq;

	unsigned long flags;

	unsigned long flags;
@@ -1927,7 +1927,7 @@ static void rcu_gp_fqs(bool first_time) 
/*

/*

 * Loop doing repeated quiescent-state forcing until the grace period ends.

 * Loop doing repeated quiescent-state forcing until the grace period ends.

 */

 */

static void rcu_gp_fqs_loop(void)

static noinline_for_stack void rcu_gp_fqs_loop(void)

{

{

	bool first_gp_fqs;

	bool first_gp_fqs;

	int gf = 0;

	int gf = 0;