On 6/13/22 8:56 AM, Ying Huang wrote:
On Fri, 2022-06-10 at 19:22 +0530, Aneesh Kumar K.V wrote:
With CONFIG_MIGRATION disabled return EINVAL on write.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
---
mm/memory-tiers.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
index 9c6b40d7e0bf..c3123a457d90 100644
--- a/mm/memory-tiers.c
+++ b/mm/memory-tiers.c
@@ -105,6 +105,9 @@ static ssize_t numa_demotion_enabled_store(struct kobject *kobj,
{
ssize_t ret;
+ if (!IS_ENABLED(CONFIG_MIGRATION))
+ return -EINVAL;
+
How about enclose numa_demotion_enabled_xxx related code with CONFIG_MIGRATION?
IIUC there is a desire to use IS_ENABLED() in the kernel instead of
#ifdef since that helps in more compile time checks. Because there are
no dead codes during compile now with IS_ENABLED().
W.r.t leaving the sysfs file visible even when CONFIG_MIGRATION is
disabled, I was thinking it gives better visibility into numa_demotion
status. I could switch to hide numa_demotion file if that is desirable.
ret = kstrtobool(buf, &numa_demotion_enabled);
if (ret)
return ret;
-aneesh
