rcu: Make rcutree module parameters visible in sysfs (7e5c2dfb) · Commits · 戴 / test

The module parameters blimit, qhimark, and qlomark (and more recently, rcu_fanout_leaf) have permission masks of zero, so that their values are not visible from sysfs. This is unnecessary and inconvenient to administrators who might like an easy way to see what these values are on a running system. This commit therefore sets their permission masks to 0444, allowing them to be read but not written. Reported-by:

Rusty Russell <rusty@ozlabs.org> Reported-by:

Josh Triplett <josh@joshtriplett.org> Signed-off-by:

Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by:

Josh Triplett <josh@joshtriplett.org>

kernel/rcutree.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -88,7 +88,7 @@ LIST_HEAD(rcu_struct_flavors);

		/* Increase (but not decrease) the CONFIG_RCU_FANOUT_LEAF at boot time. */
		static int rcu_fanout_leaf = CONFIG_RCU_FANOUT_LEAF;
		module_param(rcu_fanout_leaf, int, 0);
		module_param(rcu_fanout_leaf, int, 0444);
		int rcu_num_lvls __read_mostly = RCU_NUM_LVLS;
		static int num_rcu_lvl[] = { /* Number of rcu_nodes at specified level. */
		NUM_RCU_LVL_0,
		@@ -216,9 +216,9 @@ static int blimit = 10; /* Maximum callbacks per rcu_do_batch. */
		static int qhimark = 10000; /* If this many pending, ignore blimit. */
		static int qlowmark = 100; /* Once only this many pending, use blimit. */

		module_param(blimit, int, 0);
		module_param(qhimark, int, 0);
		module_param(qlowmark, int, 0);
		module_param(blimit, int, 0444);
		module_param(qhimark, int, 0444);
		module_param(qlowmark, int, 0444);

		int rcu_cpu_stall_suppress __read_mostly; /* 1 = suppress stall warnings. */
		int rcu_cpu_stall_timeout __read_mostly = CONFIG_RCU_CPU_STALL_TIMEOUT;

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