Commit 1ccb0745 authored by Dave Chinner's avatar Dave Chinner Committed by Dave Chinner
Browse files

xfs: avoid cil push lock if possible 



Because now it hurts when the CIL fills up.

  - 37.20% __xfs_trans_commit
      - 35.84% xfs_log_commit_cil
         - 19.34% _raw_spin_lock
            - do_raw_spin_lock
                 19.01% __pv_queued_spin_lock_slowpath
         - 4.20% xfs_log_ticket_ungrant
              0.90% xfs_log_space_wake


Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
parent 4eb56069

fs/xfs/xfs_log_cil.c

+11 −3
Original line number Diff line number Diff line
@@ -1422,10 +1422,18 @@ xlog_cil_push_background( 
	ASSERT(!test_bit(XLOG_CIL_EMPTY, &cil->xc_flags));



	/*

	 * Don't do a background push if we haven't used up all the

	 * space available yet.

	 * We are done if:

	 * - we haven't used up all the space available yet; or

	 * - we've already queued up a push; and

	 * - we're not over the hard limit; and

	 * - nothing has been over the hard limit.

	 *

	 * If so, we don't need to take the push lock as there's nothing to do.

	 */

	if (space_used < XLOG_CIL_SPACE_LIMIT(log)) {

	if (space_used < XLOG_CIL_SPACE_LIMIT(log) ||

	    (cil->xc_push_seq == cil->xc_current_sequence &&

	     space_used < XLOG_CIL_BLOCKING_SPACE_LIMIT(log) &&

	     !waitqueue_active(&cil->xc_push_wait))) {

		up_read(&cil->xc_ctx_lock);

		return;

	}