[PATCH] mm: numa: Initialse numa balancing after jump labelinitialisation

From: Mel Gorman
Date: Mon Jan 27 2014 - 10:51:51 EST


The command line parsing takes place before jump labels are initialised which
generates a warning if numa_balancing= is specified and CONFIG_JUMP_LABEL
is set. On older kernls before commit c4b2c0c5 (static_key: WARN on
usage before jump_label_init was called) the kernel would have crashed.
This patch enables automatic numa balancing later in the initialisation
process if numa_balancing= is specified.

Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
Cc: Stable <stable@xxxxxxxxxxxxxxx>
---
mm/mempolicy.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 0cd2c4d..5223684 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2657,7 +2657,7 @@ void mpol_free_shared_policy(struct shared_policy *p)
}

#ifdef CONFIG_NUMA_BALANCING
-static bool __initdata numabalancing_override;
+static int __initdata numabalancing_override;

static void __init check_numabalancing_enable(void)
{
@@ -2666,9 +2666,14 @@ static void __init check_numabalancing_enable(void)
if (IS_ENABLED(CONFIG_NUMA_BALANCING_DEFAULT_ENABLED))
numabalancing_default = true;

+ /* Parsed by setup_numabalancing. override == 1 enables, -1 disables */
+ if (numabalancing_override)
+ set_numabalancing_state(numabalancing_override == 1);
+
if (nr_node_ids > 1 && !numabalancing_override) {
- printk(KERN_INFO "Enabling automatic NUMA balancing. "
- "Configure with numa_balancing= or sysctl");
+ printk(KERN_INFO "%s automatic NUMA balancing. "
+ "Configure with numa_balancing= or sysctl",
+ numabalancing_default ? "Enabling" : "Disabling");
set_numabalancing_state(numabalancing_default);
}
}
@@ -2678,13 +2683,12 @@ static int __init setup_numabalancing(char *str)
int ret = 0;
if (!str)
goto out;
- numabalancing_override = true;

if (!strcmp(str, "enable")) {
- set_numabalancing_state(true);
+ numabalancing_override = 1;
ret = 1;
} else if (!strcmp(str, "disable")) {
- set_numabalancing_state(false);
+ numabalancing_override = -1;
ret = 1;
}
out:
--
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