Commit e5dc76b9 authored by Bob Peterson's avatar Bob Peterson Committed by Steven Whitehouse
Browse files

GFS2: Eliminate redundant calls to may_grant 



Function add_to_queue was checking may_grant for the passed-in
holder for every iteration of its gh2 loop. Now it only checks it
once at the beginning to see if a try lock is futile.

Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent 81e1d450

fs/gfs2/glock.c

+4 −5
Original line number Diff line number Diff line
@@ -954,7 +954,7 @@ __acquires(&gl->gl_spin) 
	struct gfs2_sbd *sdp = gl->gl_sbd;

	struct list_head *insert_pt = NULL;

	struct gfs2_holder *gh2;

	int try_lock = 0;

	int try_futile = 0;



	BUG_ON(gh->gh_owner_pid == NULL);

	if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
@@ -962,7 +962,7 @@ __acquires(&gl->gl_spin) 


	if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {

		if (test_bit(GLF_LOCK, &gl->gl_flags))

			try_lock = 1;

			try_futile = !may_grant(gl, gh);

		if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))

			goto fail;

	}
@@ -971,9 +971,8 @@ __acquires(&gl->gl_spin) 
		if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&

		    (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))

			goto trap_recursive;

		if (try_lock &&

		    !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) &&

		    !may_grant(gl, gh)) {

		if (try_futile &&

		    !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {

fail:

			gh->gh_error = GLR_TRYFAILED;

			gfs2_holder_wake(gh);

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