smbd: High CPU usage

[Volker Lendecke]

On Thu, Jul 19, 2018 at 09:02:30AM -0700, Jeremy Allison via samba-technical wrote:
> > I know syscalls are cheap, but don't the additional fcntl ones kill
> > the performance advantage somewhat? We had discussions with a
> > MIPS-based vendor in the past. On that platform (don't remember the
> > exact OS version), syscalls were pretty expensive.
> 
> If you want performance, use a pthreadpool :-).

Not sure in the MIPS case. This adds even more syscalls and context
switches. For better performance, we should look at preadv2 with
RWF_NOWAIT to avoid the context switch for buffered reads.

Volker

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