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Commit aacee720 authored by Bob Peterson's avatar Bob Peterson
Browse files

GFS2: Reduce contention on gfs2_log_lock 



This patch modifies functions gfs2_trans_add_meta and _data so that
they check whether the buffer_head is already in a transaction,
and if so, avoid taking the gfs2_log_lock.

Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
parent 192738b7

fs/gfs2/trans.c

+11 −2
Original line number Diff line number Diff line
@@ -170,6 +170,10 @@ void gfs2_trans_add_data(struct gfs2_glock *gl, struct buffer_head *bh) 
	}



	lock_buffer(bh);

	if (buffer_pinned(bh)) {

		set_bit(TR_TOUCHED, &tr->tr_flags);

		goto out;

	}

	gfs2_log_lock(sdp);

	bd = bh->b_private;

	if (bd == NULL) {
@@ -192,6 +196,7 @@ void gfs2_trans_add_data(struct gfs2_glock *gl, struct buffer_head *bh) 
		list_add_tail(&bd->bd_list, &tr->tr_databuf);

	}

	gfs2_log_unlock(sdp);

out:

	unlock_buffer(bh);

}
@@ -201,10 +206,14 @@ void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh) 
	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;

	struct gfs2_bufdata *bd;

	struct gfs2_meta_header *mh;

	struct gfs2_trans *tr;

	struct gfs2_trans *tr = current->journal_info;

	enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);



	lock_buffer(bh);

	if (buffer_pinned(bh)) {

		set_bit(TR_TOUCHED, &tr->tr_flags);

		goto out;

	}

	gfs2_log_lock(sdp);

	bd = bh->b_private;

	if (bd == NULL) {
@@ -220,7 +229,6 @@ void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh) 
		gfs2_log_lock(sdp);

	}

	gfs2_assert(sdp, bd->bd_gl == gl);

	tr = current->journal_info;

	set_bit(TR_TOUCHED, &tr->tr_flags);

	if (!list_empty(&bd->bd_list))

		goto out_unlock;
@@ -243,6 +251,7 @@ void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh) 
	tr->tr_num_buf_new++;

out_unlock:

	gfs2_log_unlock(sdp);

out:

	unlock_buffer(bh);

}