From patchwork Thu Oct 25 15:09:01 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhiyong Wu X-Patchwork-Id: 194222 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id F3B232C0091 for ; Fri, 26 Oct 2012 02:16:48 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935670Ab2JYPLu (ORCPT ); Thu, 25 Oct 2012 11:11:50 -0400 Received: from e9.ny.us.ibm.com ([32.97.182.139]:41825 "EHLO e9.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934530Ab2JYPLq (ORCPT ); Thu, 25 Oct 2012 11:11:46 -0400 Received: from /spool/local by e9.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Thu, 25 Oct 2012 11:11:44 -0400 Received: from d01relay05.pok.ibm.com (d01relay05.pok.ibm.com [9.56.227.237]) by d01dlp03.pok.ibm.com (Postfix) with ESMTP id 06484C90076; Thu, 25 Oct 2012 11:11:37 -0400 (EDT) Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q9PFBZFW327716; Thu, 25 Oct 2012 11:11:36 -0400 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q9PFBXjI008718; Thu, 25 Oct 2012 13:11:35 -0200 Received: from us.ibm.com ([9.115.122.193]) by d01av02.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with SMTP id q9PFBQkV008113; Thu, 25 Oct 2012 13:11:27 -0200 Received: by us.ibm.com (sSMTP sendmail emulation); Thu, 25 Oct 2012 23:11:22 +0800 From: zwu.kernel@gmail.com To: linux-fsdevel@vger.kernel.org Cc: linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, linuxram@linux.vnet.ibm.com, viro@zeniv.linux.org.uk, david@fromorbit.com, tytso@mit.edu, cmm@us.ibm.com, Zhi Yong Wu Subject: [RFC v4 09/15] vfs,hot_track: register one memory shrinker Date: Thu, 25 Oct 2012 23:09:01 +0800 Message-Id: <1351177747-19389-10-git-send-email-zwu.kernel@gmail.com> X-Mailer: git-send-email 1.7.6.5 In-Reply-To: <1351177747-19389-1-git-send-email-zwu.kernel@gmail.com> References: <1351177747-19389-1-git-send-email-zwu.kernel@gmail.com> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12102515-7182-0000-0000-000002F1F449 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: Zhi Yong Wu Register a shrinker to control the amount of memory that is used in tracking hot regions - if we are throwing inodes out of memory due to memory pressure, we most definitely are going to need to reduce the amount of memory the tracking code is using, even if it means losing useful information (i.e. the shrinker accelerates the aging process). Signed-off-by: Zhi Yong Wu --- fs/hot_tracking.c | 61 ++++++++++++++++++++++++++++++++++++++++++ include/linux/hot_tracking.h | 1 + 2 files changed, 62 insertions(+), 0 deletions(-) diff --git a/fs/hot_tracking.c b/fs/hot_tracking.c index d931083..7d2c53d 100644 --- a/fs/hot_tracking.c +++ b/fs/hot_tracking.c @@ -678,6 +678,61 @@ err: kmem_cache_destroy(hot_inode_item_cachep); } +static int hot_track_prune_map(struct hot_map_head *map_head, + bool type, int nr) +{ + struct hot_comm_item *node; + int i; + + for (i = 0; i < HEAT_MAP_SIZE; i++) { + while (!list_empty(&(map_head + i)->node_list)) { + if (nr-- <= 0) + break; + + node = list_first_entry(&(map_head + i)->node_list, + struct hot_comm_item, n_list); + if (type) { + struct hot_inode_item *hot_inode = + container_of(node, + struct hot_inode_item, hot_inode); + hot_inode_item_put(hot_inode); + } else { + struct hot_range_item *hot_range = + container_of(node, + struct hot_range_item, hot_range); + hot_range_item_put(hot_range); + } + } + } + + return nr; +} + +/* The shrinker callback function */ +static int hot_track_prune(struct shrinker *shrink, + struct shrink_control *sc) +{ + struct hot_info *root = + container_of(shrink, struct hot_info, hot_shrink); + int ret; + + if (sc->nr_to_scan == 0) + return root->hot_map_nr; + + if (!(sc->gfp_mask & __GFP_FS)) + return -1; + + ret = hot_track_prune_map(root->heat_range_map, + false, sc->nr_to_scan); + if (ret > 0) + ret = hot_track_prune_map(root->heat_inode_map, + true, ret); + if (ret > 0) + root->hot_map_nr -= (sc->nr_to_scan - ret); + + return root->hot_map_nr; +} + /* * Main function to update access frequency from read/writepage(s) hooks */ @@ -758,6 +813,11 @@ int hot_track_init(struct super_block *sb) queue_delayed_work(root->update_wq, &root->update_work, msecs_to_jiffies(HEAT_UPDATE_DELAY * MSEC_PER_SEC)); + /* Register a shrinker callback */ + root->hot_shrink.shrink = hot_track_prune; + root->hot_shrink.seeks = DEFAULT_SEEKS; + register_shrinker(&root->hot_shrink); + printk(KERN_INFO "VFS: Turning on hot data tracking\n"); return 0; @@ -774,6 +834,7 @@ void hot_track_exit(struct super_block *sb) { struct hot_info *root = sb->s_hot_root; + unregister_shrinker(&root->hot_shrink); cancel_delayed_work_sync(&root->update_work); destroy_workqueue(root->update_wq); hot_map_array_exit(root); diff --git a/include/linux/hot_tracking.h b/include/linux/hot_tracking.h index 4c5f5f3..446c99e 100644 --- a/include/linux/hot_tracking.h +++ b/include/linux/hot_tracking.h @@ -85,6 +85,7 @@ struct hot_info { struct workqueue_struct *update_wq; struct delayed_work update_work; + struct shrinker hot_shrink; }; void __init hot_cache_init(void);