From: Mikael Johansson <mpjohans@pcu.helsinki.fi>
To: Marcelo Tosatti <marcelo.tosatti@cyclades.com>
Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: RAID-0 read perf. decrease after 2.4.20
Date: Fri, 21 Nov 2003 21:56:42 +0200 (EET) [thread overview]
Message-ID: <Pine.OSF.4.58.0311212139530.519259@soul.helsinki.fi> (raw)
In-Reply-To: <Pine.LNX.4.44.0311211144130.15440-100000@logos.cnet>
Hello Marcelo and All!
On Fri, 21 Nov 2003, Marcelo Tosatti wrote:
> There have been no significant changes in the RAID driver in 2.4.21, so I
> suspect the cause for the slowdowns might the changes to the IO scheduler
> (ll_rw_blk.c) or VM changes.
>
> Isolating the -pre which the slowdown starts helps a lot.
I tested a few kernels to pin point the where tha changes occured. It
turned out that both 2.4.20 and 2.4.21-pre1 have bad read performance. The
2.4.20-ac's show good read speed. I tested it on two machines (different
from yesterday). I also checked the VIA chipset drivers version; that's
not the reason for the differences.
Athlon XP 2400+, 2.09 GHz, 1.5 GB RAM, 2*160 GB Maxtor Maxtor 6Y080L0
VIA write read
2.4.19 none 10,000 9,000 K/sec (chipset not supported)
2.4.20 3.35 73,000 88,000
2.4.20-ac1 3.35-ac 70,000 135,000
2.4.20-ac2 3.35-ac 71,000 140,000
2.4.21-pre1 3.35-ac 71,000 79,000
2.4.21-pre3 3.35-ac 71,000 79,000
Athlon 1.4 GHz, 1.5 GB RAM, 2*80 GB IC35L040AVER07-0 (IBM, I think)
2.4.13-ac8 ? 49,000 44,000 K/sec
2.4.19 3.34 53,000 41,000
2.4.20-ac2 3.35-ac 50,000 69,000
2.4.21-pre1 3.35-ac 53,000 46,000
So there was apparently something very right with the 2.4.20-ac's. It
would be nice to get it back :-)
Have a nice weekend,
Mikael J.
http://www.helsinki.fi/~mpjohans/
next prev parent reply other threads:[~2003-11-21 19:56 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-11-20 16:45 RAID-0 read perf. decrease after 2.4.20 Mikael Johansson
2003-11-21 13:47 ` Marcelo Tosatti
2003-11-21 19:56 ` Mikael Johansson [this message]
2003-12-08 12:47 ` Marcelo Tosatti
2003-12-08 13:11 ` Marc-Christian Petersen
2003-12-08 13:21 ` Marcelo Tosatti
2003-11-24 10:05 Martin Knoblauch
2003-11-25 5:01 ` Joshua Schmidlkofer
2003-11-25 9:41 Martin Knoblauch
2003-12-16 12:51 Martin Knoblauch
2003-12-18 13:41 ` Marcelo Tosatti
2003-12-18 14:37 ` Martin Knoblauch
2004-07-04 23:28 ` Mikael Johansson
2003-12-18 19:13 ` Mike Fedyk
2003-12-18 19:17 ` Marcelo Tosatti
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