This allows to test folio_split() by specifying an additional in folio
page offset parameter to split_huge_page debugfs interface.
Signed-off-by: Zi Yan <z...@nvidia.com>
---
mm/huge_memory.c | 47 ++++++++++++++++++++++++++++++++++-------------
1 file changed, 34 insertions(+), 13 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 36594eef5c24..dad6819901a8 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -4180,7 +4180,8 @@ static inline bool vma_not_suitable_for_thp_split(struct
vm_area_struct *vma)
}
static int split_huge_pages_pid(int pid, unsigned long vaddr_start,
- unsigned long vaddr_end, unsigned int new_order)
+ unsigned long vaddr_end, unsigned int new_order,
+ long in_folio_offset)
{
int ret = 0;
struct task_struct *task;
@@ -4264,8 +4265,16 @@ static int split_huge_pages_pid(int pid, unsigned long
vaddr_start,
if (!folio_test_anon(folio) && folio->mapping != mapping)
goto unlock;
- if (!split_folio_to_order(folio, target_order))
- split++;
+ if (in_folio_offset < 0 ||
+ in_folio_offset >= folio_nr_pages(folio)) {
+ if (!split_folio_to_order(folio, target_order))
+ split++;
+ } else {
+ struct page *split_at = folio_page(folio,
+ in_folio_offset);
+ if (!folio_split(folio, target_order, split_at, NULL))
+ split++;
+ }
unlock:
@@ -4288,7 +4297,8 @@ static int split_huge_pages_pid(int pid, unsigned long
vaddr_start,
}
static int split_huge_pages_in_file(const char *file_path, pgoff_t off_start,
- pgoff_t off_end, unsigned int new_order)
+ pgoff_t off_end, unsigned int new_order,
+ long in_folio_offset)
{
struct filename *file;
struct file *candidate;
@@ -4337,8 +4347,15 @@ static int split_huge_pages_in_file(const char
*file_path, pgoff_t off_start,
if (folio->mapping != mapping)
goto unlock;
- if (!split_folio_to_order(folio, target_order))
- split++;
+ if (in_folio_offset < 0 || in_folio_offset >= nr_pages) {
+ if (!split_folio_to_order(folio, target_order))
+ split++;
+ } else {
+ struct page *split_at = folio_page(folio,
+ in_folio_offset);
+ if (!folio_split(folio, target_order, split_at, NULL))
+ split++;
+ }
unlock:
folio_unlock(folio);
@@ -4371,6 +4388,7 @@ static ssize_t split_huge_pages_write(struct file *file,
const char __user *buf,
int pid;
unsigned long vaddr_start, vaddr_end;
unsigned int new_order = 0;
+ long in_folio_offset = -1;
ret = mutex_lock_interruptible(&split_debug_mutex);
if (ret)
@@ -4399,30 +4417,33 @@ static ssize_t split_huge_pages_write(struct file
*file, const char __user *buf,
goto out;
}
- ret = sscanf(tok_buf, "0x%lx,0x%lx,%d", &off_start,
- &off_end, &new_order);
- if (ret != 2 && ret != 3) {
+ ret = sscanf(tok_buf, "0x%lx,0x%lx,%d,%ld", &off_start,
&off_end,
+ &new_order, &in_folio_offset);
+ if (ret != 2 && ret != 3 && ret != 4) {
ret = -EINVAL;
goto out;
}
- ret = split_huge_pages_in_file(file_path, off_start, off_end,
new_order);
+ ret = split_huge_pages_in_file(file_path, off_start, off_end,
+ new_order, in_folio_offset);
if (!ret)
ret = input_len;
goto out;
}
- ret = sscanf(input_buf, "%d,0x%lx,0x%lx,%d", &pid, &vaddr_start,
&vaddr_end, &new_order);
+ ret = sscanf(input_buf, "%d,0x%lx,0x%lx,%d,%ld", &pid, &vaddr_start,
+ &vaddr_end, &new_order, &in_folio_offset);
if (ret == 1 && pid == 1) {
split_huge_pages_all();
ret = strlen(input_buf);
goto out;
- } else if (ret != 3 && ret != 4) {
+ } else if (ret != 3 && ret != 4 && ret != 5) {
ret = -EINVAL;
goto out;
}
- ret = split_huge_pages_pid(pid, vaddr_start, vaddr_end, new_order);
+ ret = split_huge_pages_pid(pid, vaddr_start, vaddr_end, new_order,
+ in_folio_offset);
if (!ret)
ret = strlen(input_buf);
out:
--
2.47.2
