From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id E1D767F37 for ; Mon, 24 Jun 2013 16:26:33 -0500 (CDT) Message-ID: <51C8B984.3090400@sgi.com> Date: Mon, 24 Jun 2013 16:26:28 -0500 From: Mark Tinguely MIME-Version: 1.0 Subject: Re: [PATCH 59/60] xfs: Add xfs_log_rlimit.c References: <1371617468-32559-1-git-send-email-david@fromorbit.com> <1371617468-32559-60-git-send-email-david@fromorbit.com> In-Reply-To: <1371617468-32559-60-git-send-email-david@fromorbit.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: xfs@oss.sgi.com On 06/18/13 23:51, Dave Chinner wrote: > + * 2) If the lsunit option is specified, a transaction requires 2 LSU > + * for the reservation because there are two log writes that can > + * require padding - the transaction data and the commit record which > + * are written separately and both can require padding to the LSU. > + * Consider that we can have an active CIL reservation holding 2*LSU, > + * but the CIL is not over a push threshold, in this case, if we > + * don't have enough log space for at one new transaction, which > + * includes another 2*LSU in the reservation, we will run into dead > + * loop situation in log space grant procedure. i.e. > + * xlog_grant_head_wait(). > + * > + * Hence the log size needs to be able to contain two maximally sized > + * and padded transactions, which is (2 * (2 * LSU + maxlres)). > + * Any thoughts on how we can separate the 2 * log stripe unit from the reservation. The added extended attribute calls for parent inode pointers (especially xfs_rename() where it could add up to one and remove up to two attributes) is causing a huge multiplication cnt for reservation. Those multiplications would be killers on 256KiB log stripe units. --Mark. _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs