From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id C90677CBE for ; Fri, 31 Jan 2014 21:49:02 -0600 (CST) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay3.corp.sgi.com (Postfix) with ESMTP id 3FD7CAC004 for ; Fri, 31 Jan 2014 19:48:59 -0800 (PST) Received: from aserp1040.oracle.com (aserp1040.oracle.com [141.146.126.69]) by cuda.sgi.com with ESMTP id VEc27kEspBVahss1 (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Fri, 31 Jan 2014 19:48:57 -0800 (PST) Message-ID: <52EC6EA0.9000501@oracle.com> Date: Sat, 01 Feb 2014 11:48:48 +0800 From: Jeff Liu MIME-Version: 1.0 Subject: Re: [PATCH] xfs: improve xfs_bitmap_empty() References: <52EBAF91.10608@oracle.com> <52EBBC3D.5030507@sandeen.net> <52EBC103.5050006@oracle.com> <52EBC1AF.6020000@sandeen.net> <52EBC67B.7020806@oracle.com> <52EBCF12.1020403@sgi.com> In-Reply-To: <52EBCF12.1020403@sgi.com> 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: Mark Tinguely Cc: Eric Sandeen , "xfs@oss.sgi.com" On 02/01 2014 00:28 AM, Mark Tinguely wrote: > On 01/31/14 09:51, Jeff Liu wrote: >> >> On 01/31 2014 23:30 PM, Eric Sandeen wrote: >>> On 1/31/14, 9:28 AM, Jeff Liu wrote: >>>> >>>> On 01/31 2014 23:07 PM, Eric Sandeen wrote: >>>>> On 1/31/14, 8:13 AM, Jeff Liu wrote: >>>>>> From: Jie Liu >>>>>> >>>>>> There is no need to travel through the whole bitmap items to verify >>>>>> if the bitmap array is empty or not, instead, just return 0 directly >>>>>> if an item is detected in bitmap array. >>>>>> >>>>>> Signed-off-by: Jie Liu >>>>> >>>>> Makes sense (and the long loop was my fault, I guess, but it's >>>>> better than it was, see commit 24ad33f!) >>>> >>>> Ah, you have killed a lots code there! :) >>>>> Reviewed-by: Eric Sandeen >>>>> >>>>> I wonder if something like: >>>>> >>>>> return (find_first_set(map, size) == size); >>>>> >>>>> would be faster (or if it'd be worth it)...? >>>>> Probably not. :) >>>>> >>>> >>>> Well, when I looking through our bitmap source, I once thought if >>>> we can replace the current code with the generic bitmap library. >>>> However, our map is uint rather than unsigned long... >>> >>> Technically the unsigned long (pointer) is just the bitmap address, >>> I think. >> >> Yeah, so this might worth to try on long terms. >> > > The blf_data_map[] is int aligned, not long aligned. > You could reflect the alignment difference in the offset or > change the alignment in the structure. > For now, I think we can not simply turn to generic bitmap just because of the alignment difference on 64-bits OS. Thanks, -Jeff _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs