Commit 44984691 authored by Kefeng Wang's avatar Kefeng Wang
Browse files

mm: huge_memory: add thp mapping align control 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9Q9DF


CVE: NA

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

Since folio_get_unmapped_area() is experimental, add a sysfs interface
to enable/disable it, it is disabled by default, and could be enabled
by /sys/kernel/mm/transparent_hugepage/thp_mapping_align.

Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
parent 13d01786

Documentation/admin-guide/mm/transhuge.rst

+9 −0
Original line number Diff line number Diff line
@@ -211,6 +211,15 @@ possible to enable/disable it by configurate the corresponding bit:: 
	echo 0x2 >/sys/kernel/mm/transparent_hugepage/thp_exec_enabled

	echo 0x3 >/sys/kernel/mm/transparent_hugepage/thp_exec_enabled



The kernel could try to enable other larger size mappings align other

than THP size, eg, 64K on arm64, BIT0 for file mapping, BIT1 for anon

mapping, it is disabled by default, and could enable this feature by

writing the corresponding bit to 1::



	echo 0x1 >/sys/kernel/mm/transparent_hugepage/thp_mapping_align

	echo 0x2 >/sys/kernel/mm/transparent_hugepage/thp_mapping_align

	echo 0x3 >/sys/kernel/mm/transparent_hugepage/thp_mapping_align



khugepaged will be automatically started when one or more hugepage

sizes are enabled (either by directly setting "always" or "madvise",

or by setting "inherit" while the top-level enabled is set to "always"

include/linux/huge_mm.h

+2 −0
Original line number Diff line number Diff line
@@ -52,6 +52,8 @@ enum transparent_hugepage_flag { 
	TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG,

	TRANSPARENT_HUGEPAGE_FILE_EXEC_THP_FLAG,

	TRANSPARENT_HUGEPAGE_FILE_EXEC_MTHP_FLAG,

	TRANSPARENT_HUGEPAGE_FILE_MAPPING_ALIGN_FLAG,

	TRANSPARENT_HUGEPAGE_ANON_MAPPING_ALIGN_FLAG,

};



struct kobject;

mm/huge_memory.c

+61 −6
Original line number Diff line number Diff line
@@ -434,8 +434,7 @@ static struct kobj_attribute hpage_pmd_size_attr = 
#define FILE_EXEC_MTHP_ENABLE	BIT(1)

#define FILE_EXEC_THP_ALL	(FILE_EXEC_THP_ENABLE | FILE_EXEC_MTHP_ENABLE)



static void thp_exec_enabled_set(enum transparent_hugepage_flag flag,

				 bool enable)

static void thp_flag_set(enum transparent_hugepage_flag flag, bool enable)

{

	if (enable)

		set_bit(flag, &transparent_hugepage_flags);
@@ -473,13 +472,13 @@ static ssize_t thp_exec_enabled_store(struct kobject *kobj, 
		return -EINVAL;



#ifdef CONFIG_READ_ONLY_THP_FOR_FS

	thp_exec_enabled_set(TRANSPARENT_HUGEPAGE_FILE_EXEC_THP_FLAG,

	thp_flag_set(TRANSPARENT_HUGEPAGE_FILE_EXEC_THP_FLAG,

		     val & FILE_EXEC_THP_ENABLE);

	ret = start_stop_khugepaged();

	if (ret)

		return ret;

#endif

	thp_exec_enabled_set(TRANSPARENT_HUGEPAGE_FILE_EXEC_MTHP_FLAG,

	thp_flag_set(TRANSPARENT_HUGEPAGE_FILE_EXEC_MTHP_FLAG,

		     val & FILE_EXEC_MTHP_ENABLE);



	return count;
@@ -487,6 +486,47 @@ static ssize_t thp_exec_enabled_store(struct kobject *kobj, 
static struct kobj_attribute thp_exec_enabled_attr =

	__ATTR_RW(thp_exec_enabled);



#define FILE_MAPPING_ALIGN	BIT(0)

#define ANON_MAPPING_ALIGN	BIT(1)

#define THP_MAPPING_ALIGN_ALL	(FILE_MAPPING_ALIGN | ANON_MAPPING_ALIGN)



static ssize_t thp_mapping_align_show(struct kobject *kobj,

				      struct kobj_attribute *attr, char *buf)

{

	unsigned long val = 0;



	if (test_bit(TRANSPARENT_HUGEPAGE_FILE_MAPPING_ALIGN_FLAG,

		     &transparent_hugepage_flags))

		val |= FILE_MAPPING_ALIGN;



	if (test_bit(TRANSPARENT_HUGEPAGE_ANON_MAPPING_ALIGN_FLAG,

		     &transparent_hugepage_flags))

		val |= ANON_MAPPING_ALIGN;



	return sysfs_emit(buf, "0x%lx\n", val);

}

static ssize_t thp_mapping_align_store(struct kobject *kobj,

		struct kobj_attribute *attr, const char *buf, size_t count)

{

	unsigned long val;

	int ret;



	ret = kstrtoul(buf, 16, &val);

	if (ret < 0)

		return ret;

	if (val & ~THP_MAPPING_ALIGN_ALL)

		return -EINVAL;



	thp_flag_set(TRANSPARENT_HUGEPAGE_FILE_MAPPING_ALIGN_FLAG,

		     val & FILE_MAPPING_ALIGN);

	thp_flag_set(TRANSPARENT_HUGEPAGE_ANON_MAPPING_ALIGN_FLAG,

		     val & ANON_MAPPING_ALIGN);



	return count;

}

static struct kobj_attribute thp_mapping_align_attr =

	__ATTR_RW(thp_mapping_align);



static struct attribute *hugepage_attr[] = {

	&enabled_attr.attr,

	&defrag_attr.attr,
@@ -496,6 +536,7 @@ static struct attribute *hugepage_attr[] = { 
	&shmem_enabled_attr.attr,

#endif

	&thp_exec_enabled_attr.attr,

	&thp_mapping_align_attr.attr,

	NULL,

};
@@ -887,10 +928,21 @@ static unsigned long __thp_get_unmapped_area(struct file *filp, 
	return ret;

}



#define thp_file_mapping_align_enabled()			\

	(transparent_hugepage_flags &				\

	 (1<<TRANSPARENT_HUGEPAGE_FILE_MAPPING_ALIGN_FLAG))



#define thp_anon_mapping_align_enabled()			\

	(transparent_hugepage_flags &				\

	 (1<<TRANSPARENT_HUGEPAGE_ANON_MAPPING_ALIGN_FLAG))



static bool file_mapping_align_enabled(struct file *filp)

{

	struct address_space *mapping;



	if (!thp_file_mapping_align_enabled())

		return false;



	if (!filp)

		return false;
@@ -905,6 +957,9 @@ static bool anon_mapping_align_enabled(int order) 
{

	unsigned long mask;



	if (!thp_anon_mapping_align_enabled())

		return 0;



	mask = READ_ONCE(huge_anon_orders_always) |

	       READ_ONCE(huge_anon_orders_madvise);