[vlc-devel] [PATCH 0/1] Improve SFTP network performance with buffer

[Ilkka Ollakka]

On Fri, Mar 02, 2018 at 08:42:22PM +0100, Martin Disch wrote:
> First after applying your patch, playback did not work at all, instead
> stopping with "sftp stream error: read failed". I checked which error
> it was that libssh2 was returning that caused this and it turned out
> to be -31, which is LIBSSH2_ERROR_SFTP_PROTOCOL. I have no idea why
> this happens on my system when it works on yours, but it's not that
> big of a problem.

Most likely different libssh2 versions

> doing for the EAGAIN error, which did the job. I didn't do any
> elaborate measurements, but just looking at the bandwidth usage I
> didn't see an improvement. I was using a large prefetch buffer again,
> hoping to see the prefetch module fill it up quickly using all
> available bandwidth, but unlike when using a large read size, it
> didn't manage. It barely used enough bandwidth to keep up with
> playback and couldn't really prefetch anything.

Ok, I think following sysctl configs that I have might also be root of
why I see different results on bw-usage etc.

---
net.core.default_qdisc=fq
net.ipv4.tcp_congestion_control=bbr
---

But I'll check some reruns on different approaches on how libssh2 could
be used and how that affects on latency/bw utilisation when I have some
spare time.

-- 
Ilkka Ollakka