Hello all!
I was not very satisfied with raid1 read performance,
so i tried to make things better.
The result is small patch against 2.2.13ac kernel. (attachment)
You can also find it at: http://www.iki.fi/miku/raid1
In my hardware it performs better against the stock raid code.
But YMMV. I have 166Mhz Pentium with AIC-7880 Ultra SCSI with 2
WDE9180 ULTRA2 drives.
I do not have chance to test it in any other hardware
setup so i decided to present it to public, here in linux-raid.
It works for me so chances are it might work for someone else also.
Here is some figures i found out:
Kernel Threads MBytesread/sec Seeks/sec
-------------------------------------------------------------------
original 1 16.1 167.2
patched 1 16.4 192.5
original 2 10.2 202.7
patched 2 21.9 284.0
original 10 10.1 145.6
patched 10 19.2 254.2
where:
original = 2.2.13 with ac patch set attached
patched = original + raid1_read_balance patch attached
---- cli clip --
These figures are from tiotest program, which spawns n thread
each with own file, then sequentially reads thru that file and
performs randoms seeks inside that file. You can find this
program at here: www.iki.fi/miku/tiotest
Because both the patch and test benchmark is written by me,
be sceptical...very sceptical :)
WARNING: Do NOT go and apply this patch do your production
machines. Unless you are exceptionally brave (or stupid :)
Flames, comments, improvemnts and different
varying benchmarks are all greatly appreciated!
-- Mika <[EMAIL PROTECTED]>
raid1-readbalance-patch2.gz
