RE: [PATCH 00/16] raid acceleration and asynchronous offload api for 2.6.22

Williams, Dan J
2007-05-02T15:45:23Z

> From: Nick Piggin [mailto:nickpiggin@yahoo.com.au]
> > I am pleased to release this latest spin of the raid acceleration
> > patches for merge consideration. This release aims to address all
> > pending review items including MD bug fixes and async_tx api changes
> > from Neil, and concerns on channel management from Chris and others.
> >
> > Data integrity tests using home grown scripts and 'iozone -V' are
> > passing. I am open to suggestions for additional testing criteria.
>
> Do you have performance numbers?
>
Patch #4 outlines the throughput gains as reported by tiobench. 20-30%
for sequential writes, and 40-55% for degraded reads.

Here are some recent screen captures of a resync operation with and
without offload, this is on an iop13xx platform:

mdadm --create /dev/md0 /dev/sd[abc] missing -n 4 -l 5
mdadm --add /dev/md0 /dev/sdd

---
CONFIG_DMA_ENGINE = n

top - 00:01:39 up 1 min, 1 user, load average: 0.77, 0.20, 0.06
Tasks: 50 total, 1 running, 49 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.3% us, 47.4% sy, 0.0% ni, 49.0% id, 0.0% wa, 0.7% hi,
2.6% si
Mem: 2074836k total, 36276k used, 2038560k free, 0k buffers
Swap: 0k total, 0k used, 0k free, 16560k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1307 root 11 -5 0 0 0 S 48.0 0.0 0:14.14 md0_raid5
1319 root 15 0 2260 1052 868 R 0.3 0.1 0:00.12 top

iq81340mc:~# cat /proc/mdstat
Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md0 : active raid5 sda[0] sdd[4] sdc[2] sdb[1]
468872448 blocks level 5, 64k chunk, algorithm 2 [4/3] [UUU_]
[>....................] recovery = 0.7% (1104000/156290816)
finish=108.1min speed=23919K/sec

---
CONFIG_DMA_ENGINE = y && CONFIG_INTEL_IOP_ADMA = y

top - 00:06:21 up 6 min, 1 user, load average: 1.10, 0.68, 0.29
Tasks: 51 total, 1 running, 50 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.5% us, 7.5% sy, 0.1% ni, 85.8% id, 1.9% wa, 0.5% hi,
3.5% si
Mem: 2074776k total, 40520k used, 2034256k free, 0k buffers
Swap: 0k total, 0k used, 0k free, 19448k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1354 root 10 -5 0 0 0 S 11.6 0.0 0:29.32 md0_raid5
1491 root 18 0 2256 964 780 R 1.9 0.0 0:00.03 top

iq81340mc:/mnt# cat /proc/mdstat
Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md0 : active raid5 sdd[4] sdc[2] sdb[1] sda[0]
468872448 blocks level 5, 64k chunk, algorithm 2 [4/3] [UUU_]
[>....................] recovery = 3.5% (5474916/156290816)
finish=52.2min speed=48061K/sec

Some older iozone data is available here:
https://sourceforge.net/project/showfiles.php?group_id=115074&package_id
=203776

Regards,
Dan