From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J. R. Okajima" Subject: Re: [PATCH 10/12] NFS: Simplify nfs_wb_page() Date: Thu, 11 Mar 2010 03:51:49 +0900 Message-ID: <16839.1268247109@jrobl> References: <20100125221544.16750.70574.stgit@localhost.localdomain> <20100125221545.16750.19154.stgit@localhost.localdomain> Cc: linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Wu Fengguang , Peter Zijlstra , Jan Kara , Steve Rago , Jens Axboe , Peter Staubach , Arjan van de Ven , Ingo Molnar , linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Christoph Hellwig , Al Viro To: Trond Myklebust Return-path: In-Reply-To: <20100125221545.16750.19154.stgit-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org> Sender: linux-nfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org Trond Myklebust: > -static int nfs_wb_page_priority(struct inode *inode, struct page *page, > - int how) > +/* > + * Write back all requests on one page - we do this before reading it. > + */ > +int nfs_wb_page(struct inode *inode, struct page *page) > { ::: > - do { > + while(PagePrivate(page)) { > if (clear_page_dirty_for_io(page)) { > ret = nfs_writepage_locked(page, &wbc); > if (ret < 0) > goto out_error; > - } else if (!PagePrivate(page)) > + } > + req = nfs_find_and_lock_request(page); > + if (!req) > break; > - ret = nfs_sync_mapping_wait(page->mapping, &wbc, how); > - if (ret < 0) > + if (IS_ERR(req)) { > + ret = PTR_ERR(req); > goto out_error; ::: Hello Trond, I am unsure whether this nfs_find_and_lock_request() call is correct or not, but it brings me a problem. This call trace in "kswapd blocked for more than brabra" message shows that generic_delete_inode() blocked. Is this put_nfs_open_context() -- iput() call in shrink_page_list() context intended? If not, I'd suggest a patch like this. INFO: task kswapd0:305 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kswapd0 D 0000000000000001 0 305 2 0x00000000 ffff88001f21d4f0 0000000000000046 ffff88001fdea680 ffff88001f21c000 ffff88001f21dfd8 ffff88001f21c000 ffff88001f21dfd8 ffff88001f21dfd8 ffff88001fdea040 0000000000014c00 0000000000000001 ffff88001fdea040 Call Trace: [] io_schedule+0x4d/0x70 [] sync_page+0x65/0xa0 [] __wait_on_bit_lock+0x52/0xb0 [] ? sync_page+0x0/0xa0 [] __lock_page+0x64/0x70 [] ? wake_bit_function+0x0/0x40 [] truncate_inode_pages_range+0x344/0x4a0 [] truncate_inode_pages+0x10/0x20 [] generic_delete_inode+0x15e/0x190 [] generic_drop_inode+0x5d/0x80 [] iput+0x78/0x80 [] nfs_dentry_iput+0x38/0x50 [] dentry_iput+0x84/0x110 [] d_kill+0x2e/0x60 [] dput+0x7a/0x170 [] path_put+0x15/0x40 [] __put_nfs_open_context+0xa4/0xb0 [] ? nfs_free_request+0x0/0x50 [] put_nfs_open_context+0xb/0x10 [] nfs_free_request+0x29/0x50 [] kref_put+0x8e/0xe0 [] nfs_release_request+0x14/0x20 [] nfs_find_and_lock_request+0x89/0xa0 [] nfs_wb_page+0x80/0x110 [] nfs_release_page+0x70/0x90 [] try_to_release_page+0x5e/0x80 [] shrink_page_list+0x638/0x860 [] shrink_zone+0x63e/0xc40 [] ? _raw_spin_unlock+0x57/0x70 [] ? up_read+0x1e/0x40 [] kswapd+0x6c9/0xa20 [] ? isolate_pages_global+0x0/0x280 [] ? autoremove_wake_function+0x0/0x40 [] ? kswapd+0x0/0xa20 [] kthread+0x96/0xb0 [] kernel_thread_helper+0x4/0x10 [] ? restore_args+0x0/0x30 [] ? kthread+0x0/0xb0 [] ? kernel_thread_helper+0x0/0x10 no locks held by kswapd0/305. diff --git a/fs/nfs/file.c b/fs/nfs/file.c index ae8d022..ffa5463 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -491,8 +491,13 @@ static int nfs_release_page(struct page *page, gfp_t gfp) { dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page); - if (gfp & __GFP_WAIT) + if (gfp & __GFP_WAIT) { + struct inode *inode; + + inode = igrab(page->mapping->host); nfs_wb_page(page->mapping->host, page); + iput(inode); + } /* If PagePrivate() is set, then the page is not freeable */ if (PagePrivate(page)) return 0; J. R. Okajima -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html