From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id 152B07CAE for ; Fri, 26 Aug 2016 11:02:17 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay2.corp.sgi.com (Postfix) with ESMTP id DA6F9304048 for ; Fri, 26 Aug 2016 09:02:13 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id w8fatV6dWqOY8VP0 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Fri, 26 Aug 2016 09:02:11 -0700 (PDT) Date: Fri, 26 Aug 2016 12:02:09 -0400 From: Brian Foster Subject: Re: [PATCH 3/4] xfs: make xfs_inode_set_eofblocks_tag cheaper for the common case Message-ID: <20160826160209.GB17728@bfoster.bfoster> References: <1471816273-28940-1-git-send-email-hch@lst.de> <1471816273-28940-4-git-send-email-hch@lst.de> <20160825123808.GC25041@bfoster.bfoster> <20160826142616.GA21535@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20160826142616.GA21535@lst.de> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Christoph Hellwig Cc: xfs@oss.sgi.com On Fri, Aug 26, 2016 at 04:26:16PM +0200, Christoph Hellwig wrote: > On Thu, Aug 25, 2016 at 08:38:09AM -0400, Brian Foster wrote: > > I'm guessing the lockless check is intentional, but is that really > > necessary? E.g., it doesn't seem like using ->i_flags_lock > > unconditionally should affect performance in the way the AG lock or > > radix tree work does, particularly since we're already holding > > IOLOCK_EXCL in the current implementation. I could be wrong, but FWIW, > > we do already have xfs_iflags_test_and_set() sitting around as well... > > I don't think taking it should be too bad, but given the ops ordering > it also seems entirely pointless to even take it. > Then why are we taking it? I assumed it at least served as a memory barrier... Brian > _______________________________________________ > xfs mailing list > xfs@oss.sgi.com > http://oss.sgi.com/mailman/listinfo/xfs _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs