Re: [PATCH v6 00/11] VFS hot tracking

From: Zhi Yong Wu
Date: Mon Nov 11 2013 - 10:43:59 EST


ping? any plan to review?

On Wed, Nov 6, 2013 at 9:45 PM, Zhi Yong Wu <zwu.kernel@xxxxxxxxx> wrote:
> From: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
>
> The patchset is trying to introduce hot tracking function in
> VFS layer, which will keep track of real disk I/O in memory.
> By it, you will easily know more details about disk I/O, and
> then detect where disk I/O hot spots are. Also, specific FS
> can take use of it to do accurate defragment, and hot relocation
> support, etc.
>
> Now it's time to send out its V6 for external review, and
> any comments or ideas are appreciated, thanks.
>
> NOTE:
>
> The patchset can be obtained via my kernel dev git on github:
> git://github.com/wuzhy/kernel.git hot_tracking
> If you're interested, you can also review them via
> https://github.com/wuzhy/kernel/commits/hot_tracking
>
> For how to use and more other info and performance report,
> please check hot_tracking.txt in Documentation and following
> links:
> 1.) http://lwn.net/Articles/525651/
> 2.) https://lkml.org/lkml/2012/12/20/199
>
> This patchset has been done scalability or performance tests
> by fs_mark, ffsb and compilebench.
>
> The perf testings were done on Linux 3.12.0-rc7 with Model IBM,8231-E2C
> Big Endian PPC64 with 64 CPUs and 2 NUMA nodes, 250G RAM and 1.50 TiB
> test hard disk where each test file size is 20G or 100G.
> Architecture: ppc64
> Byte Order: Big Endian
> CPU(s): 64
> On-line CPU(s) list: 0-63
> Thread(s) per core: 4
> Core(s) per socket: 1
> Socket(s): 16
> NUMA node(s): 2
> Model: IBM,8231-E2C
> Hypervisor vendor: pHyp
> Virtualization type: full
> L1d cache: 32K
> L1i cache: 32K
> L2 cache: 256K
> L3 cache: 4096K
> NUMA node0 CPU(s): 0-31
> NUMA node1 CPU(s): 32-63
>
> Below is the perf testing report:
>
> Please focus on the two key points:
> - The overall overhead which is injected by the patchset
> - The stability of the perf results
>
> 1. fio tests
>
> w/o hot tracking w/ hot tracking
>
> RAM size 32G 32G 16G 8G 4G 2G 250G
>
> sequential-8k-1jobs-read 61260KB/s 60918KB/s 60901KB/s 62610KB/s 60992KB/s 60213KB/s 60948KB/s
>
> sequential-8k-1jobs-write 1329KB/s 1329KB/s 1328KB/s 1329KB/s 1328KB/s 1329KB/s 1329KB/s
>
> sequential-8k-8jobs-read 91139KB/s 92614KB/s 90907KB/s 89895KB/s 92022KB/s 90851KB/s 91877KB/s
>
> sequential-8k-8jobs-write 2523KB/s 2522KB/s 2516KB/s 2521KB/s 2516KB/s 2518KB/s 2521KB/s
>
> sequential-256k-1jobs-read 151432KB/s 151403KB/s 151406KB/s 151422KB/s 151344KB/s 151446KB/s 151372KB/s
>
> sequential-256k-1jobs-write 33451KB/s 33470KB/s 33481KB/s 33470KB/s 33459KB/s 33472KB/s 33477KB/s
>
> sequential-256k-8jobs-read 235291KB/s 234555KB/s 234251KB/s 233656KB/s 234927KB/s 236380KB/s 235535KB/s
>
> sequential-256k-8jobs-write 62419KB/s 62402KB/s 62191KB/s 62859KB/s 62629KB/s 62720KB/s 62523KB/s
>
> random-io-mix-8k-1jobs [READ] 2929KB/s 2942KB/s 2946KB/s 2929KB/s 2934KB/s 2947KB/s 2946KB/s
> [WRITE] 1262KB/s 1266KB/s 1257KB/s 1262KB/s 1257KB/s 1257KB/s 1265KB/s
>
> random-io-mix-8k-8jobs [READ] 2444KB/s 2442KB/s 2436KB/s 2416KB/s 2353KB/s 2441KB/s 2442KB/s
> [WRITE] 1047KB/s 1044KB/s 1047KB/s 1028KB/s 1017KB/s 1034KB/s 1049KB/s
>
> random-io-mix-8k-16jobs [READ] 2182KB/s 2184KB/s 2169KB/s 2178KB/s 2190KB/s 2184KB/s 2180KB/s
> [WRITE] 932KB/s 930KB/s 943KB/s 936KB/s 937KB/s 929KB/s 931KB/s
>
> The above perf parameter is the aggregate bandwidth of threads in the group;
> If you hope to know how about other perf parameters, or fio raw results, please let me know, thanks.
>
> 2. Locking stat - Contention & Cacheline Bouncing
>
> RAM size class name con-bounces contentions acq-bounces acquisitions cacheline bouncing locking contention
> ratio ratio
>
> &(&root->t_lock)->rlock: 1508 1592 157834 374639292 0.96% 0.00%
> 250G &(&root->m_lock)->rlock: 1469 1484 119221 43077842 1.23% 0.00%
> &(&he->i_lock)->rlock: 0 0 101879 376755218 0.00% 0.00%
>
> &(&root->t_lock)->rlock: 2912 2985 342575 374691186 0.85% 0.00%
> 32G &(&root->m_lock)->rlock: 188 193 307765 8803163 0.00% 0.00%
> &(&he->i_lock)->rlock: 0 0 291860 376756084 0.00% 0.00%
>
> &(&root->t_lock)->rlock: 3863 3948 298041 374727038 1.30% 0.00%
> 16G &(&root->m_lock)->rlock: 220 228 254451 8687057 0.00% 0.00%
> &(&he->i_lock)->rlock: 0 0 235027 376756830 0.00% 0.00%
>
> &(&root->t_lock)->rlock: 3283 3409 233790 374722064 1.40% 0.00%
> 8G &(&root->m_lock)->rlock: 136 139 203917 8684313 0.00% 0.00%
> &(&he->i_lock)->rlock: 0 0 193746 376756438 0.00% 0.00%
>
> &(&root->t_lock)->rlock: 15090 15705 283460 374889666 5.32% 0.00%
> 4G &(&root->m_lock)->rlock: 172 173 222480 8555052 0.00% 0.00%
> &(&he->i_lock)->rlock: 0 0 206431 376759452 0.00% 0.00%
>
> &(&root->t_lock)->rlock: 25515 27368 305129 375394828 8.36% 0.00%
> 2G &(&root->m_lock)->rlock: 100 101 216516 6752265 0.00% 0.00%
> &(&he->i_lock)->rlock: 0 0 214713 376765169 0.00% 0.00%
>
> 3. Perf test - Cacheline Ping-pong
>
> w/o hot tracking w/ hot tracking
>
> RAM size 32G 32G 16G 8G 4G 2G 250G
>
> cache-references 1,264,996,437,581 1,401,504,955,577 1,398,308,614,801 1,396,525,544,527 1,384,793,467,410 1,432,042,560,409 1,571,627,148,771
>
> cache-misses 45,424,567,057 58,432,749,807 59,200,504,032 59,762,030,933 58,104,156,576 57,283,962,840 61,963,839,419
>
> seconds time elapsed 22956.327674298 23035.457069488 23017.232397085 23012.397142967 23008.420970731 23057.245578767 23342.456015188
>
> cache-misses ratio 3.591 % 4.169 % 4.234 % 4.279 % 4.196 % 4.000 % 3.943 %
>
> Changelog from v5:
> - Also added the hook hot_freqs_update() in the page cache I/O path,
> not only in real disk I/O path [viro]
> - Don't export the stuff until it's used by a module [viro]
> - Splitted hot_inode_item_lookup() [viro]
> - Prevented hot items from being re-created after the inode was unlinked. [viro]
> - Made hot_freqs_update() to be inline and adopt one private hot flag [viro]
> - Killed hot_bit_shift() [viro]
> - Used file_inode() instead of file->f_dentry->d_inode [viro]
> - Introduced one new file hot_tracking.h in include/uapi/linux/ [viro]
> - Made the checks for ->i_nlink to be protectd by ->i_mutex [viro]
>
> v5:
> - Added all kinds of perf testing report [viro]
> - Covered mmap() now [viro]
> - Removed list_sort() in hot_update_worker() to avoid locking contention
> and cacheline bouncing [viro]
> - Removed a /proc interface to control low memory usage [Chandra]
> - Adjusted shrinker support due to the change of public shrinker APIs [zwu]
> - Fixed the locking missing issue when hot_inode_item_put() is called
> in ioctl_heat_info() [viro]
> - Fixed some locking contention issues [zwu]
>
> v4:
> - Removed debugfs support, but leave it to TODO list [viro, Chandra]
> - Killed HOT_DELETING and HOT_IN_LIST flag [viro]
> - Fixed unlink issues [viro]
> - Fixed the issue on lookups (both for inode and range)
> leak on race with unlink [viro]
> - Killed hot_comm_item and split the functions which take it [virio]
> - Fixed some other issues [zwu, Chandra]
>
> v3:
> - Added memory caping function for hot items [Zhiyong]
> - Cleanup aging function [Zhiyong]
>
> v2:
> - Refactored to be under RCU [Chandra Seetharaman]
> Merged some code changes [Chandra Seetharaman]
> - Fixed some issues [Chandra Seetharaman]
>
> v1:
> - Solved 64 bits inode number issue. [David Sterba]
> - Embed struct hot_type in struct file_system_type [Darrick J. Wong]
> - Cleanup Some issues [David Sterba]
> - Use a static hot debugfs root [Greg KH]
>
> rfcv4:
> - Introduce hot func registering framework [Zhiyong]
> - Remove global variable for hot tracking [Zhiyong]
> - Add btrfs hot tracking support [Zhiyong]
>
> rfcv3:
> 1.) Rewritten debugfs support based seq_file operation. [Dave Chinner]
> 2.) Refactored workqueue support. [Dave Chinner]
> 3.) Turn some Micro into be tunable [Zhiyong, Liu Zheng]
> TIME_TO_KICK, and HEAT_UPDATE_DELAY
> 4.) Cleanedup a lot of other issues [Dave Chinner]
>
>
> rfcv2:
> 1.) Converted to Radix trees, not RB-tree [Zhiyong, Dave Chinner]
> 2.) Added memory shrinker [Dave Chinner]
> 3.) Converted to one workqueue to update map info periodically [Dave Chinner]
> 4.) Cleanedup a lot of other issues [Dave Chinner]
>
> rfcv1:
> 1.) Reduce new files and put all in fs/hot_tracking.[ch] [Dave Chinner]
> 2.) The first three patches can probably just be flattened into one.
> [Marco Stornelli , Dave Chinner]
>
>
> Dave Chinner (1):
> VFS hot tracking, xfs: Add hot tracking support
>
> Zhi Yong Wu (10):
> VFS hot tracking: Define basic data structures and functions
> VFS hot tracking: Track IO and record heat information
> VFS hot tracking: Add a workqueue to move items between hot maps
> VFS hot tracking: Add shrinker functionality to curtail memory usage
> VFS hot tracking: Add an ioctl to get hot tracking information
> VFS hot tracking: Add a /proc interface to make the interval tunable
> VFS hot tracking: Add a /proc interface to control memory usage
> VFS hot tracking: Add documentation
> VFS hot tracking, btrfs: Add hot tracking support
> MAINTAINERS: add the maintainers for VFS hot tracking
>
> Documentation/filesystems/00-INDEX | 2 +
> Documentation/filesystems/hot_tracking.txt | 207 ++++++++
> MAINTAINERS | 12 +
> fs/Makefile | 2 +-
> fs/btrfs/ctree.h | 1 +
> fs/btrfs/super.c | 22 +-
> fs/compat_ioctl.c | 5 +
> fs/dcache.c | 2 +
> fs/hot_tracking.c | 816 +++++++++++++++++++++++++++++
> fs/hot_tracking.h | 72 +++
> fs/ioctl.c | 71 +++
> fs/namei.c | 4 +
> fs/xfs/xfs_mount.h | 1 +
> fs/xfs/xfs_super.c | 18 +
> include/linux/fs.h | 4 +
> include/linux/hot_tracking.h | 107 ++++
> include/uapi/linux/fs.h | 1 +
> include/uapi/linux/hot_tracking.h | 33 ++
> kernel/sysctl.c | 14 +
> mm/filemap.c | 24 +-
> mm/readahead.c | 6 +
> 21 files changed, 1420 insertions(+), 4 deletions(-)
> create mode 100644 Documentation/filesystems/hot_tracking.txt
> create mode 100644 fs/hot_tracking.c
> create mode 100644 fs/hot_tracking.h
> create mode 100644 include/linux/hot_tracking.h
> create mode 100644 include/uapi/linux/hot_tracking.h
>
> --
> 1.7.11.7
>
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--
Regards,

Zhi Yong Wu
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