From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id o7NAaEZ4126008 for ; Mon, 23 Aug 2010 05:36:14 -0500 Received: from bombadil.infradead.org (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 8AF8215D80FE for ; Mon, 23 Aug 2010 03:46:33 -0700 (PDT) Received: from bombadil.infradead.org (bombadil.infradead.org [18.85.46.34]) by cuda.sgi.com with ESMTP id HN0P8sM2EFGWRyka for ; Mon, 23 Aug 2010 03:46:33 -0700 (PDT) Date: Mon, 23 Aug 2010 06:36:47 -0400 From: Christoph Hellwig Subject: Re: [PATCH 2/2] xfs: improve buffer cache hash scalability Message-ID: <20100823103647.GB7268@infradead.org> References: <1282522546-7892-1-git-send-email-david@fromorbit.com> <1282522546-7892-3-git-send-email-david@fromorbit.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1282522546-7892-3-git-send-email-david@fromorbit.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 Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: xfs@oss.sgi.com > @@ -1443,8 +1438,7 @@ xfs_alloc_bufhash( > { > unsigned int i; > > - btp->bt_hashshift = external ? 3 : 8; /* 8 or 256 buckets */ > - btp->bt_hashmask = (1 << btp->bt_hashshift) - 1; > + btp->bt_hashshift = external ? 3 : 12; /* 8 or 4096 buckets */ Not directly related to the patch, but we never have hashes buffers on the log device. And on the RT device we only use hashed buffers twice to verify the device size. With a little work on the latter we can stop allocating the buf hash entirely for the RT and log devices. Anyway, the patch looks good for now, although we should try to get rid of the hash long term. Reviewed-by: Christoph Hellwig _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs