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Posted to dev@subversion.apache.org by Paul Hammant <pa...@hammant.org> on 2016/10/31 12:27:29 UTC
Svn perf curiosity
I'm curious as to what could make a checkin of a single 10MB file take 3 mins on a Linux machine, when it is 2 seconds on a Mac.
I'm able to reproduce it easily:
svnadmin create --fs-type fsx fsxRoot
svn checkout file://$(pwd)/fsxRoot testLocalCheckout
cd testLocalCheckout
openssl rand 10000000 | base64 > banana
svn add banana
time svn ci -m "test banana"
The same (physical not virtual) Linux machine isn't generally slow - the creation of the file and the copying of it around, takes a couple seconds on that machine, and there's no load on the box at any time. The drive is SSD, but the same poor perf happens if you run the same test on USB3 drive attached.
The results are the same for FSFS and FSX, by the way.
Svn is at v1.9.3 on that Ubuntu 16.04 box - but I couldn't see anything in the changelog that noted it as slow that was fixed in v1.9.4.
- Paul
Re: Svn perf curiosity
Posted by Paul Hammant <pa...@hammant.org>.
OK, two things:
1. I was using UsbMount for the USB mounted hard drive, and it is slow by
default - writes are double-checked as they're written. Ref 'sync' in
https://github.com/hfuchs/usbmount/blob/master/usbmount.conf - so much time
lost :-(
MoreUtils' sponge (via pipe) made it faster to the same USB hard drive -
different low-level libc calls to openssl?
2. I made a mistake about the built in SSD - it was fast regardless,
despite previous advice.
- Paul
On Mon, Oct 31, 2016 at 8:27 AM, Paul Hammant <pa...@hammant.org> wrote:
> I'm curious as to what could make a checkin of a single 10MB file take 3
> mins on a Linux machine, when it is 2 seconds on a Mac.
>
>
>
> I'm able to reproduce it easily:
>
>
>
> svnadmin create --fs-type fsx fsxRoot
>
> svn checkout file://$(pwd)/fsxRoot testLocalCheckout
>
> cd testLocalCheckout
>
> openssl rand 10000000 | base64 > banana
>
> svn add banana
>
> time svn ci -m "test banana"
>
>
>
> The same (physical not virtual) Linux machine isn't generally slow - the
> creation of the file and the copying of it around, takes a couple seconds
> on that machine, and there's no load on the box at any time. The drive is
> SSD, but the same poor perf happens if you run the same test on USB3 drive
> attached.
>
>
>
> The results are the same for FSFS and FSX, by the way.
>
>
> Svn is at v1.9.3 on that Ubuntu 16.04 box - but I couldn't see anything
> in the changelog that noted it as slow that was fixed in v1.9.4.
>
>
>
> - Paul
>
>
Re: Svn perf curiosity
Posted by Paul Hammant <pa...@hammant.org>.
I created a Gist for this -
https://gist.github.com/paul-hammant/0581dd8062afbe1b6d19a42bba9a72dd
I wasn't hard for people to run the above, but it is a little easier now.
On Mon, Oct 31, 2016 at 8:27 AM, Paul Hammant <pa...@hammant.org> wrote:
> I'm curious as to what could make a checkin of a single 10MB file take 3
> mins on a Linux machine, when it is 2 seconds on a Mac.
>
>
>
> I'm able to reproduce it easily:
>
>
>
> svnadmin create --fs-type fsx fsxRoot
>
> svn checkout file://$(pwd)/fsxRoot testLocalCheckout
>
> cd testLocalCheckout
>
> openssl rand 10000000 | base64 > banana
>
> svn add banana
>
> time svn ci -m "test banana"
>
>
>
> The same (physical not virtual) Linux machine isn't generally slow - the
> creation of the file and the copying of it around, takes a couple seconds
> on that machine, and there's no load on the box at any time. The drive is
> SSD, but the same poor perf happens if you run the same test on USB3 drive
> attached.
>
>
>
> The results are the same for FSFS and FSX, by the way.
>
>
> Svn is at v1.9.3 on that Ubuntu 16.04 box - but I couldn't see anything
> in the changelog that noted it as slow that was fixed in v1.9.4.
>
>
>
> - Paul
>
>