Subject: RE: Libssh2 usage from cURL with various buffer sizes.

RE: Libssh2 usage from cURL with various buffer sizes.

From: Patrik Thunström <>
Date: Fri, 18 Nov 2011 16:42:42 +0100

-----Original Message-----
From: Daniel Stenberg []
Sent: den 18 november 2011 15:35
To: libssh2 development
Subject: RE: Libssh2 usage from cURL with various buffer sizes.

> If you can write up a recipe for that we can use, it'd be great!

Sure, I'm on it! Sadly I'm more in cURL territory, so my test driver will be
a compacted code running through libcURL, if that's okay? I know it would be
better if I could patch together a pure libssh2 driver, but I hope my
libcURL driver will be better than nothing.

Or would you prefer a more conceptual step by step instruction?

>> So, it's a clear improvement, but instead other issues have surfaced.
>> Not sure how related they could be to the improvements made.

> I don't think it is a too interesting question either. The code in git is
the best we have, and if there are bugs we should fix them...

Yes, definitely! The snapshot is miles better in terms of performance to
start off with, so I see no reason to try to look at older code versions to
try to salvage or something like that, I was more implying that it might be
related to those parts of code that has changed.

>> Also, slowdown over multiple files is still noticeable when running it
>> with a larger buffer. This is however a lot less of an issue, as it
>> can always be worked around by reinitializing the connection to the

> If you can write up a test recipe for this case, perhaps someone more than
you can have a look at the details to try to see what the reason for this

Yup, this will probably work out just fine to run with the same test driver
I'm already preparing for the read_dir stall.
I'm not too worried about this issue, as it might just be my mind playing
tricks, and I believe it'll also be a bit easier to verify and rule out the
SFTP server's role In slowing down once the above mentioned issue is solved.
Will return to this issue a bit later.

I'll get back once I've made a test driver!

Best regards
Patrik Thunström /

Received on 2011-11-18