[PATCH 3.11 192/233] mm: numa: initialise numa balancing after jump label initialisation

From: Luis Henriques
Date: Fri Feb 07 2014 - 07:07:59 EST


3.11.10.4 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Mel Gorman <mgorman@xxxxxxx>

commit c297663c0b3930491a3cb2aba4b6e5a7159c3503 upstream.

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 kernels before commit c4b2c0c5f647 ("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>
Acked-by: Rik van Riel <riel@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
[ luis: backported to 3.11: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
mm/mempolicy.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 4baf12e..bfa95cf 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2524,7 +2524,7 @@ 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)
{
@@ -2533,9 +2533,15 @@ 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 the "
+ "kernel.numa_balancing sysctl",
+ numabalancing_default ? "Enabling" : "Disabling");
set_numabalancing_state(numabalancing_default);
}
}
@@ -2545,13 +2551,12 @@ 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:
--
1.8.3.2

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