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Commit f7977793 authored by Jason Baron's avatar Jason Baron Committed by Linus Torvalds
Browse files

speed up madvise_need_mmap_write() usage 



In the new madvise_need_mmap_write() call we can avoid an extra case
statement and function call as follows.

Signed-off-by: default avatarJason Baron <jbaron@redhat.com>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 897e679b

mm/madvise.c

+4 −2
Original line number Original line Diff line number Diff line
@@ -287,9 +287,11 @@ asmlinkage long sys_madvise(unsigned long start, size_t len_in, int behavior) 
	struct vm_area_struct * vma, *prev;

	struct vm_area_struct * vma, *prev;

	int unmapped_error = 0;

	int unmapped_error = 0;

	int error = -EINVAL;

	int error = -EINVAL;

	int write;

	size_t len;

	size_t len;





	if (madvise_need_mmap_write(behavior))

	write = madvise_need_mmap_write(behavior);

	if (write)

		down_write(&current->mm->mmap_sem);

		down_write(&current->mm->mmap_sem);

	else

	else

		down_read(&current->mm->mmap_sem);

		down_read(&current->mm->mmap_sem);
@@ -354,7 +356,7 @@ asmlinkage long sys_madvise(unsigned long start, size_t len_in, int behavior) 
			vma = find_vma(current->mm, start);

			vma = find_vma(current->mm, start);

	}

	}

out:

out:

	if (madvise_need_mmap_write(behavior))

	if (write)

		up_write(&current->mm->mmap_sem);

		up_write(&current->mm->mmap_sem);

	else

	else

		up_read(&current->mm->mmap_sem);

		up_read(&current->mm->mmap_sem);