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Date:      Fri, 06 May 2005 13:44:42 -0600
From:      Scott Long <scottl@samsco.org>
To:        Kris Kennaway <kris@obsecurity.org>
Cc:        sparc64@freebsd.org
Subject:   Re: [kris@obsecurity.org: Re: Benchmarking mpsafevfs with parallel tarball extraction]
Message-ID:  <427BC92A.9030603@samsco.org>
In-Reply-To: <20050506191600.GA77799@xor.obsecurity.org>
References:  <20050506191600.GA77799@xor.obsecurity.org>

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sparc64 is slow in general, and seems to have gotten significantly 
slower in the past 6 months.  It took me 30+ hours to build a 6-current
release (including docs and ports) earlier this week.  A year ago it 
took closer to 20 hours IIRC.  This is on a Ultra2 with 300MHz CPUs,
512MB of RAM, and two disks on the local esp controller.  Definitely
much slower than it should be.

Scott


Kris Kennaway wrote:
> BTW, any ideas why md is so slow on sparc64?
> 
> Kris
> 
> ----- Forwarded message from Kris Kennaway <kris@obsecurity.org> -----
> 
> Date: Fri, 6 May 2005 11:48:52 -0700
> From: Kris Kennaway <kris@obsecurity.org>
> To: Kris Kennaway <kris@obsecurity.org>
> Cc: smp@FreeBSD.org, current@FreeBSD.org
> Subject: Re: Benchmarking mpsafevfs with parallel tarball extraction
> In-Reply-To: <20050506183529.GA46411@xor.obsecurity.org>
> User-Agent: Mutt/1.4.2.1i
> 
> On Fri, May 06, 2005 at 11:35:29AM -0700, Kris Kennaway wrote:
> 
> 
>>I might be bumping into the bandwidth of md here - when I ran less
>>rigorous tests with lower concurrency of extractions I seemed to be
>>getting marginally better performance (about an effective concurrency
>>of 2.2 for both 3 and 10 simultaneous extractions - so at least it
>>doesn't seem to degrade badly).  Or this might be reflecting VFS lock
>>contention (which there is certainly a lot of, according to mutex
>>profiling traces).
> 
> 
> I suspect that I am hitting the md bandwidth:
> 
> # dd if=/dev/zero of=/dev/md0 bs=1024k count=500
> 500+0 records in
> 500+0 records out
> 524288000 bytes transferred in 9.501760 secs (55177988 bytes/sec)
> 
> which is a lot worse than I expected (even for a 400MHz CPU).
> 
> For some reason I get better performance writing to a filesystem
> mounted on this md:
> 
> # dd if=/dev/zero of=foo bs=1024k count=500
> 500+0 records in
> 500+0 records out
> 524288000 bytes transferred in 7.943042 secs (66005946 bytes/sec)
> # rm foo
> # dd if=/dev/zero of=foo bs=1024k count=500
> 500+0 records in
> 500+0 records out
> 524288000 bytes transferred in 7.126929 secs (73564364 bytes/sec)
> # rm foo
> # dd if=/dev/zero of=foo bs=1024k count=500
> 500+0 records in
> 500+0 records out
> 524288000 bytes transferred in 7.237668 secs (72438804 bytes/sec)
> 
> If the write bandwidth is only 50-70MB/sec, then it won't be hard to
> saturate, so I won't probe the full scalability of mpsafevfs here.
> 
> Kris
> 
> 
> ----- End forwarded message -----



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