smbd: High CPU usage

Vadim Lazovskiy vadim.lazovskiy at
Thu Jul 19 07:19:14 UTC 2018

Thank you for your effort.
Patch works for me. At least no cpu-hogs now.

I'm very unfamiliar with samba internals, but this approach looks
Is it possible to put socket fd into event loop? Saw samba using epoll.
Or wouldn't it be better to make socket blocking forever?
Or can't do that because smbd have to accept some commands from client even
when client reads data.


ср, 18 июл. 2018 г. в 22:40, Jeremy Allison <jra at>:

> On Wed, Jul 18, 2018 at 09:20:10PM +0300, Vadim Lazovskiy via
> samba-technical wrote:
> > I would not agree.
> > sendfile is great. It makes you able to serve content directly from disk
> to
> > network without unnessesery copying to userspace. It saves you lots
> > syscalls and context switching.
> > As for our workload profile (1-2Gbit per server) it really saves CPU
> time.
> >
> > If someone of samba developers treat this as bug and eager to fix it I
> > could provide extra information and do some debugging.
> Can you try this (Linux-only) patch ?
> If you can confirm it works I'll log a bug and create
> fixes for the other sendfile() versions also.
> Jeremy.

Vadim Lazovskiy

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