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: kernel test robot <lkp@intel.com>
Tested-by: Rong Chen <rong.a.chen@intel.com>
[ paulmck: noinline_for_stack per Nathan Chancellor. ]
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit is contained in:
Paul E. McKenney 2021-06-07 21:57:02 -07:00
parent d9ee962feb
commit f74126dcbc

View file

@ -1733,7 +1733,7 @@ static void rcu_strict_gp_boundary(void *unused)
/*
* 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 flags;
@ -1927,7 +1927,7 @@ static void rcu_gp_fqs(bool first_time)
/*
* 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;
int gf = 0;