Introduce HUGE_VMALLOC_DEFAULT_ENABLED and make it default y, this
let user to choose whether or not enable huge vmalloc mappings by
default.
Meanwhile, add new hugevmalloc=on/off parameter to enable or disable
this feature at boot time, nohugevmalloc is still supported and
equivalent to hugevmalloc=off.
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
.../admin-guide/kernel-parameters.txt | 12 ++++++++++++
mm/Kconfig | 8 ++++++++
mm/vmalloc.c | 18 +++++++++++++++++-
3 files changed, 37 insertions(+), 1 deletion(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index a069d8fe2fee..7b2f900fd243 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1638,6 +1638,18 @@
If both parameters are enabled, hugetlb_free_vmemmap takes
precedence over memory_hotplug.memmap_on_memory.
+
+ hugevmalloc= [PPC] Reguires CONFIG_HAVE_ARCH_HUGE_VMALLOC
+ Format: { on | off }
+ Default set by CONFIG_HUGE_VMALLOC_DEFAULT_ENABLED.
+
+ This parameter enables/disables kernel huge vmalloc
+ mappings at boot time.
+
+ on: Enable the feature
+ off: Disable the feature
+ Equivalent to: nohugevmalloc
+
hung_task_panic=
[KNL] Should the hung task detector generate panics.
Format: 0 | 1
diff --git a/mm/Kconfig b/mm/Kconfig
index a99bd499ef51..8d8a92f22905 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -262,6 +262,14 @@ config HUGETLB_PAGE_SIZE_VARIABLE
HUGETLB_PAGE_ORDER when there are multiple HugeTLB page sizes available
on a platform.
+config HUGE_VMALLOC_DEFAULT_ENABLED
+ bool "Enable huge vmalloc mappings by default"
+ default y
+ depends on HAVE_ARCH_HUGE_VMALLOC
+ help
+ Enable huge vmalloc mappings by default, this value could be overridden
+ by hugevmalloc=off|on.
+
config CONTIG_ALLOC
def_bool (MEMORY_ISOLATION && COMPACTION) || CMA
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 9bf838817a47..0d0f8deb5639 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -60,7 +60,7 @@ static const unsigned int ioremap_max_page_shift = PAGE_SHIFT;
#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
-static bool __ro_after_init vmap_allow_huge = true;
+static bool __ro_after_init vmap_allow_huge = IS_ENABLED(CONFIG_HUGE_VMALLOC_DEFAULT_ENABLED);
static int __init set_nohugevmalloc(char *str)
{
@@ -68,6 +68,22 @@ static int __init set_nohugevmalloc(char *str)
return 0;
}
early_param("nohugevmalloc", set_nohugevmalloc);
+
+static int __init set_hugevmalloc(char *str)
+{
+ if (!str)
+ return -EINVAL;
+
+ if (!strcmp(str, "on"))
+ vmap_allow_huge = true;
+ else if (!strcmp(str, "off"))
+ vmap_allow_huge = false;
+ else
+ return -EINVAL;
+
+ return 0;
+}
+early_param("hugevmalloc", set_hugevmalloc);
#else /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
static const bool vmap_allow_huge = false;
#endif /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
--
2.26.2
