Commit 49b960de authored by Muchun Song's avatar Muchun Song Committed by Andrew Morton
Browse files

mm: hugetlb_vmemmap: move mmap lock to vmemmap_remap_range() 

All the users of vmemmap_remap_range() will hold the mmap lock and release
it once it returns, it is naturally to move the lock to
vmemmap_remap_range() to simplify the code and the users.

Link: https://lkml.kernel.org/r/20231205030853.3921-1-songmuchun@bytedance.com


Signed-off-by: default avatarMuchun Song <songmuchun@bytedance.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 47e61d88

mm/hugetlb_vmemmap.c

+4 −13
Original line number Diff line number Diff line
@@ -163,8 +163,10 @@ static int vmemmap_remap_range(unsigned long start, unsigned long end, 


	VM_BUG_ON(!PAGE_ALIGNED(start | end));



	mmap_read_lock(&init_mm);

	ret = walk_page_range_novma(&init_mm, start, end, &vmemmap_remap_ops,

				    NULL, walk);

	mmap_read_unlock(&init_mm);

	if (ret)

		return ret;
@@ -282,7 +284,6 @@ static void vmemmap_restore_pte(pte_t *pte, unsigned long addr, 
static int vmemmap_remap_split(unsigned long start, unsigned long end,

			       unsigned long reuse)

{

	int ret;

	struct vmemmap_remap_walk walk = {

		.remap_pte	= NULL,

		.flags		= VMEMMAP_SPLIT_NO_TLB_FLUSH,
@@ -291,11 +292,7 @@ static int vmemmap_remap_split(unsigned long start, unsigned long end, 
	/* See the comment in the vmemmap_remap_free(). */

	BUG_ON(start - reuse != PAGE_SIZE);



	mmap_read_lock(&init_mm);

	ret = vmemmap_remap_range(reuse, end, &walk);

	mmap_read_unlock(&init_mm);



	return ret;

	return vmemmap_remap_range(reuse, end, &walk);

}



/**
@@ -358,7 +355,6 @@ static int vmemmap_remap_free(unsigned long start, unsigned long end, 
	 */

	BUG_ON(start - reuse != PAGE_SIZE);



	mmap_read_lock(&init_mm);

	ret = vmemmap_remap_range(reuse, end, &walk);

	if (ret && walk.nr_walked) {

		end = reuse + walk.nr_walked * PAGE_SIZE;
@@ -377,7 +373,6 @@ static int vmemmap_remap_free(unsigned long start, unsigned long end, 


		vmemmap_remap_range(reuse, end, &walk);

	}

	mmap_read_unlock(&init_mm);



	return ret;

}
@@ -434,11 +429,7 @@ static int vmemmap_remap_alloc(unsigned long start, unsigned long end, 
	if (alloc_vmemmap_page_list(start, end, &vmemmap_pages))

		return -ENOMEM;



	mmap_read_lock(&init_mm);

	vmemmap_remap_range(reuse, end, &walk);

	mmap_read_unlock(&init_mm);



	return 0;

	return vmemmap_remap_range(reuse, end, &walk);

}



DEFINE_STATIC_KEY_FALSE(hugetlb_optimize_vmemmap_key);