From: zwu.kernel@gmail.com Subject: [RFC v4+ hot_track 01/19] vfs: introduce private radix tree structures Date: Mon, 29 Oct 2012 12:30:43 +0800 Message-ID: <1351485061-12297-2-git-send-email-zwu.kernel@gmail.com> References: <1351485061-12297-1-git-send-email-zwu.kernel@gmail.com> 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, wuzhy@linux.vnet.ibm.com, wenqing.lz@taobao.com To: linux-fsdevel@vger.kernel.org Return-path: In-Reply-To: <1351485061-12297-1-git-send-email-zwu.kernel@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org From: Zhi Yong Wu One root structure hot_info is defined, is hooked up in super_block, and will be used to hold radix tree root, hash list root and some other information, etc. Adds hot_inode_tree struct to keep track of frequently accessed files, and be keyed by {inode, offset}. Trees contain hot_inode_items representing those files and ranges. Having these trees means that vfs can quickly determine the temperature of some data by doing some calculations on the hot_freq_data struct that hangs off of the tree item. Define two items hot_inode_item and hot_range_item, one of them represents one tracked file to keep track of its access frequency and the tree of ranges in this file, while the latter represents a file range of one inode. Each of the two structures contains a hot_freq_data struct with its frequency of access metrics (number of {reads, writes}, last {read,write} time, frequency of {reads,writes}). Also, each hot_inode_item contains one hot_range_tree struct which is keyed by {inode, offset, length} and used to keep track of all the ranges in this file. Signed-off-by: Zhi Yong Wu --- fs/Makefile | 2 +- fs/dcache.c | 2 + fs/hot_tracking.c | 108 ++++++++++++++++++++++++++++++++++++++++++ fs/hot_tracking.h | 23 +++++++++ include/linux/hot_tracking.h | 73 ++++++++++++++++++++++++++++ 5 files changed, 207 insertions(+), 1 deletions(-) create mode 100644 fs/hot_tracking.c create mode 100644 fs/hot_tracking.h create mode 100644 include/linux/hot_tracking.h diff --git a/fs/Makefile b/fs/Makefile index 1d7af79..f966dea 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -11,7 +11,7 @@ obj-y := open.o read_write.o file_table.o super.o \ attr.o bad_inode.o file.o filesystems.o namespace.o \ seq_file.o xattr.o libfs.o fs-writeback.o \ pnode.o drop_caches.o splice.o sync.o utimes.o \ - stack.o fs_struct.o statfs.o + stack.o fs_struct.o statfs.o hot_tracking.o ifeq ($(CONFIG_BLOCK),y) obj-y += buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o diff --git a/fs/dcache.c b/fs/dcache.c index 3a463d0..7d5be16 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -37,6 +37,7 @@ #include #include #include +#include #include "internal.h" #include "mount.h" @@ -3172,4 +3173,5 @@ void __init vfs_caches_init(unsigned long mempages) mnt_init(); bdev_cache_init(); chrdev_init(); + hot_cache_init(); } diff --git a/fs/hot_tracking.c b/fs/hot_tracking.c new file mode 100644 index 0000000..badf47d --- /dev/null +++ b/fs/hot_tracking.c @@ -0,0 +1,108 @@ +/* + * fs/hot_tracking.c + * + * Copyright (C) 2012 IBM Corp. All rights reserved. + * Written by Zhi Yong Wu + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "hot_tracking.h" + +/* kmem_cache pointers for slab caches */ +static struct kmem_cache *hot_inode_item_cachep __read_mostly; +static struct kmem_cache *hot_range_item_cachep __read_mostly; + +/* + * Initialize the inode tree. Should be called for each new inode + * access or other user of the hot_inode interface. + */ +static void hot_inode_tree_init(struct hot_info *root) +{ + INIT_RADIX_TREE(&root->hot_inode_tree, GFP_ATOMIC); + spin_lock_init(&root->lock); +} + +/* + * Initialize the hot range tree. Should be called for each new inode + * access or other user of the hot_range interface. + */ +void hot_range_tree_init(struct hot_inode_item *he) +{ + INIT_RADIX_TREE(&he->hot_range_tree, GFP_ATOMIC); + spin_lock_init(&he->lock); +} + +/* + * Initialize a new hot_range_item structure. The new structure is + * returned with a reference count of one and needs to be + * freed using free_range_item() + */ +static void hot_range_item_init(struct hot_range_item *hr, u32 start, + struct hot_inode_item *he) +{ + hr->start = start; + hr->len = RANGE_SIZE; + hr->hot_inode = he; + kref_init(&hr->hot_range.refs); + spin_lock_init(&hr->hot_range.lock); + hr->hot_range.hot_freq_data.avg_delta_reads = (u64) -1; + hr->hot_range.hot_freq_data.avg_delta_writes = (u64) -1; + hr->hot_range.hot_freq_data.flags = FREQ_DATA_TYPE_RANGE; +} + +/* + * Initialize a new hot_inode_item structure. The new structure is + * returned with a reference count of one and needs to be + * freed using hot_free_inode_item() + */ +static void hot_inode_item_init(struct hot_inode_item *he, u64 ino, + struct radix_tree_root *hot_inode_tree) +{ + he->i_ino = ino; + he->hot_inode_tree = hot_inode_tree; + kref_init(&he->hot_inode.refs); + spin_lock_init(&he->hot_inode.lock); + he->hot_inode.hot_freq_data.avg_delta_reads = (u64) -1; + he->hot_inode.hot_freq_data.avg_delta_writes = (u64) -1; + he->hot_inode.hot_freq_data.flags = FREQ_DATA_TYPE_INODE; + hot_range_tree_init(he); +} + +/* + * Initialize kmem cache for hot_inode_item and hot_range_item. + */ +void __init hot_cache_init(void) +{ + hot_inode_item_cachep = kmem_cache_create("hot_inode_item", + sizeof(struct hot_inode_item), 0, + SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, + NULL); + if (!hot_inode_item_cachep) + return; + + hot_range_item_cachep = kmem_cache_create("hot_range_item", + sizeof(struct hot_range_item), 0, + SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, + NULL); + if (!hot_range_item_cachep) + goto err; + + return; + +err: + kmem_cache_destroy(hot_inode_item_cachep); +} +EXPORT_SYMBOL_GPL(hot_cache_init); diff --git a/fs/hot_tracking.h b/fs/hot_tracking.h new file mode 100644 index 0000000..febf699 --- /dev/null +++ b/fs/hot_tracking.h @@ -0,0 +1,23 @@ +/* + * fs/hot_tracking.h + * + * Copyright (C) 2012 IBM Corp. All rights reserved. + * Written by Zhi Yong Wu + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + */ + +#ifndef __HOT_TRACKING__ +#define __HOT_TRACKING__ + +#include +#include +#include + +/* values for hot_freq_data flags */ +#define FREQ_DATA_TYPE_INODE (1 << 0) +#define FREQ_DATA_TYPE_RANGE (1 << 1) + +#endif /* __HOT_TRACKING__ */ diff --git a/include/linux/hot_tracking.h b/include/linux/hot_tracking.h new file mode 100644 index 0000000..1cec0aa --- /dev/null +++ b/include/linux/hot_tracking.h @@ -0,0 +1,73 @@ +/* + * include/linux/hot_tracking.h + * + * This file has definitions for VFS hot data tracking + * structures etc. + * + * Copyright (C) 2012 IBM Corp. All rights reserved. + * Written by Zhi Yong Wu + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + */ + +#ifndef _LINUX_HOTTRACK_H +#define _LINUX_HOTTRACK_H + +#include +#include +#include +#include + +/* + * A frequency data struct holds values that are used to + * determine temperature of files and file ranges. These structs + * are members of hot_inode_item and hot_range_item + */ +struct hot_freq_data { + struct timespec last_read_time; + struct timespec last_write_time; + u32 nr_reads; + u32 nr_writes; + u64 avg_delta_reads; + u64 avg_delta_writes; + u32 flags; + u32 last_temp; +}; + +/* The common info for both following structures */ +struct hot_comm_item { + struct hot_freq_data hot_freq_data; /* frequency data */ + spinlock_t lock; /* protects object data */ + struct kref refs; /* prevents kfree */ +}; + +/* An item representing an inode and its access frequency */ +struct hot_inode_item { + struct hot_comm_item hot_inode; /* node in hot_inode_tree */ + struct radix_tree_root hot_range_tree; /* tree of ranges */ + spinlock_t lock; /* protect range tree */ + struct radix_tree_root *hot_inode_tree; + u64 i_ino; /* inode number from inode */ +}; + +/* + * An item representing a range inside of + * an inode whose frequency is being tracked + */ +struct hot_range_item { + struct hot_comm_item hot_range; + struct hot_inode_item *hot_inode; /* associated hot_inode_item */ + u32 start; /* item index in hot_range_tree */ + u32 len; /* length in bytes */ +}; + +struct hot_info { + struct radix_tree_root hot_inode_tree; + spinlock_t lock; /*protect inode tree */ +}; + +extern void __init hot_cache_init(void); + +#endif /* _LINUX_HOTTRACK_H */ -- 1.7.6.5