Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933402AbZJGNMj (ORCPT ); Wed, 7 Oct 2009 09:12:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933136AbZJGNMj (ORCPT ); Wed, 7 Oct 2009 09:12:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:16156 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933082AbZJGNMh (ORCPT ); Wed, 7 Oct 2009 09:12:37 -0400 Message-ID: <4ACC9373.6080703@redhat.com> Date: Wed, 07 Oct 2009 09:11:15 -0400 From: Peter Staubach User-Agent: Thunderbird 2.0.0.22 (X11/20090609) MIME-Version: 1.0 To: Wu Fengguang CC: Andrew Morton , Theodore Tso , Christoph Hellwig , Dave Chinner , Chris Mason , Peter Zijlstra , Li Shaohua , Myklebust Trond , "jens.axboe@oracle.com" , Jan Kara , Nick Piggin , linux-fsdevel@vger.kernel.org, LKML Subject: Re: [PATCH 44/45] NFS: remove NFS_INO_FLUSHING lock References: <20091007073818.318088777@intel.com> <20091007074906.867871013@intel.com> In-Reply-To: <20091007074906.867871013@intel.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3544 Lines: 92 Wu Fengguang wrote: > It was introduced in 72cb77f4a5ac, and the several issues have been > addressed in generic writeback: > - out of order writeback (or interleaved concurrent writeback) > addressed by the per-bdi writeback and wait queue in balance_dirty_pages() > - sync livelocked by a fast dirtier > addressed by throttling all to-be-synced dirty inodes > I don't think that we can just remove this support. It is designed to reduce the effects from doing a stat(2) on a file which is being actively written to. If we do remove it, then we will need to replace this patch with another. Trond and I hadn't quite finished discussing some aspects of that other patch... :-) Thanx... ps > CC: Peter Zijlstra > CC: Peter Staubach > CC: Trond Myklebust > Signed-off-by: Wu Fengguang > --- > fs/nfs/file.c | 9 --------- > fs/nfs/write.c | 11 ----------- > include/linux/nfs_fs.h | 1 - > 3 files changed, 21 deletions(-) > > --- linux.orig/fs/nfs/file.c 2009-10-07 14:31:45.000000000 +0800 > +++ linux/fs/nfs/file.c 2009-10-07 14:32:54.000000000 +0800 > @@ -386,15 +386,6 @@ static int nfs_write_begin(struct file * > mapping->host->i_ino, len, (long long) pos); > > start: > - /* > - * Prevent starvation issues if someone is doing a consistency > - * sync-to-disk > - */ > - ret = wait_on_bit(&NFS_I(mapping->host)->flags, NFS_INO_FLUSHING, > - nfs_wait_bit_killable, TASK_KILLABLE); > - if (ret) > - return ret; > - > page = grab_cache_page_write_begin(mapping, index, flags); > if (!page) > return -ENOMEM; > --- linux.orig/fs/nfs/write.c 2009-10-07 14:31:45.000000000 +0800 > +++ linux/fs/nfs/write.c 2009-10-07 14:32:54.000000000 +0800 > @@ -387,26 +387,15 @@ static int nfs_writepages_callback(struc > int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc) > { > struct inode *inode = mapping->host; > - unsigned long *bitlock = &NFS_I(inode)->flags; > struct nfs_pageio_descriptor pgio; > int err; > > - /* Stop dirtying of new pages while we sync */ > - err = wait_on_bit_lock(bitlock, NFS_INO_FLUSHING, > - nfs_wait_bit_killable, TASK_KILLABLE); > - if (err) > - goto out_err; > - > nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES); > > nfs_pageio_init_write(&pgio, inode, wb_priority(wbc)); > err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio); > nfs_pageio_complete(&pgio); > > - clear_bit_unlock(NFS_INO_FLUSHING, bitlock); > - smp_mb__after_clear_bit(); > - wake_up_bit(bitlock, NFS_INO_FLUSHING); > - > if (err < 0) > goto out_err; > err = pgio.pg_error; > --- linux.orig/include/linux/nfs_fs.h 2009-10-07 14:31:45.000000000 +0800 > +++ linux/include/linux/nfs_fs.h 2009-10-07 14:32:54.000000000 +0800 > @@ -208,7 +208,6 @@ struct nfs_inode { > #define NFS_INO_STALE (1) /* possible stale inode */ > #define NFS_INO_ACL_LRU_SET (2) /* Inode is on the LRU list */ > #define NFS_INO_MOUNTPOINT (3) /* inode is remote mountpoint */ > -#define NFS_INO_FLUSHING (4) /* inode is flushing out data */ > #define NFS_INO_FSCACHE (5) /* inode can be cached by FS-Cache */ > #define NFS_INO_FSCACHE_LOCK (6) /* FS-Cache cookie management lock */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/