From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:36674 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751345AbdFFNco (ORCPT ); Tue, 6 Jun 2017 09:32:44 -0400 Date: Tue, 6 Jun 2017 09:32:42 -0400 From: Brian Foster Subject: Re: [PATCH 01/13] xfs: optimize _btree_query_all Message-ID: <20170606133239.GA51630@bfoster.bfoster> References: <149643863965.23065.10505493683913299340.stgit@birch.djwong.org> <149643864610.23065.12274956619066749994.stgit@birch.djwong.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <149643864610.23065.12274956619066749994.stgit@birch.djwong.org> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org On Fri, Jun 02, 2017 at 02:24:06PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong > > Don't bother wandering our way through the leaf nodes when the caller > issues a query_all; just zoom down the left side of the tree and walk > rightwards along level zero. > > Signed-off-by: Darrick J. Wong > --- > fs/xfs/libxfs/xfs_btree.c | 44 +++++++++++++++++++++++++++++++++++++++----- > 1 file changed, 39 insertions(+), 5 deletions(-) > > > diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c > index 3a673ba..07d75bc 100644 > --- a/fs/xfs/libxfs/xfs_btree.c > +++ b/fs/xfs/libxfs/xfs_btree.c > @@ -4849,12 +4849,46 @@ xfs_btree_query_all( > xfs_btree_query_range_fn fn, > void *priv) > { > - union xfs_btree_irec low_rec; > - union xfs_btree_irec high_rec; > + union xfs_btree_rec *recp; > + int stat; > + int error; > + > + /* > + * Find the leftmost record. The btree cursor must be set > + * to the low record used to generate low_key. > + */ > + memset(&cur->bc_rec, 0, sizeof(cur->bc_rec)); > + stat = 0; > + error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, &stat); > + if (error) > + goto out; > + > + /* Nothing? See if there's anything to the right. */ > + if (!stat) { > + error = xfs_btree_increment(cur, 0, &stat); > + if (error) > + goto out; > + } > > - memset(&low_rec, 0, sizeof(low_rec)); > - memset(&high_rec, 0xFF, sizeof(high_rec)); > - return xfs_btree_query_range(cur, &low_rec, &high_rec, fn, priv); > + while (stat) { > + /* Find the record. */ > + error = xfs_btree_get_rec(cur, &recp, &stat); > + if (error || !stat) > + break; > + > + /* Callback */ > + error = fn(cur, recp, priv); > + if (error < 0 || error == XFS_BTREE_QUERY_RANGE_ABORT) > + break; > + > + /* Move on to the next record. */ > + error = xfs_btree_increment(cur, 0, &stat); > + if (error) > + break; > + } > + > +out: > + return error; This all looks quite similar to xfs_btree_simple_query_range(), minus the associated key checks. I doubt the latter measurably affects the performance of a btree walk. Could we call that function directly here? Brian > } > > /* > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html