[PATCH v11 3/4] mm: hugetlb_vmemmap: use kstrtobool for hugetlb_vmemmap param parsing

From: Muchun Song
Date: Thu May 12 2022 - 00:12:41 EST


Use kstrtobool rather than open coding "on" and "off" parsing in
mm/hugetlb_vmemmap.c, which is more powerful to handle all kinds
of parameters like 'Yy1Nn0' or [oO][NnFf] for "on" and "off".

Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
---
Documentation/admin-guide/kernel-parameters.txt | 6 +++---
mm/hugetlb_vmemmap.c | 10 +++++-----
2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 308da668bbb1..43b8385073ad 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1703,10 +1703,10 @@
enabled.
Allows heavy hugetlb users to free up some more
memory (7 * PAGE_SIZE for each 2MB hugetlb page).
- Format: { on | off (default) }
+ Format: { [oO][Nn]/Y/y/1 | [oO][Ff]/N/n/0 (default) }

- on: enable the feature
- off: disable the feature
+ [oO][Nn]/Y/y/1: enable the feature
+ [oO][Ff]/N/n/0: disable the feature

Built with CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON=y,
the default is on.
diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index 6254bb2d4ae5..cc4ec752ec16 100644
--- a/mm/hugetlb_vmemmap.c
+++ b/mm/hugetlb_vmemmap.c
@@ -28,15 +28,15 @@ EXPORT_SYMBOL(hugetlb_optimize_vmemmap_key);

static int __init hugetlb_vmemmap_early_param(char *buf)
{
- if (!buf)
+ bool enable;
+
+ if (kstrtobool(buf, &enable))
return -EINVAL;

- if (!strcmp(buf, "on"))
+ if (enable)
static_branch_enable(&hugetlb_optimize_vmemmap_key);
- else if (!strcmp(buf, "off"))
- static_branch_disable(&hugetlb_optimize_vmemmap_key);
else
- return -EINVAL;
+ static_branch_disable(&hugetlb_optimize_vmemmap_key);

return 0;
}
--
2.11.0