From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Monjalon <thomas.monjalon@6wind.com>
Subject: Re: [PATCH v7 4/8] vhost: rxtx: use queue id instead of
	constant ring index
Date: Wed, 21 Oct 2015 17:52:47 +0200
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Cc: dev@dpdk.org, "marcel@redhat.com" <marcel@redhat.com>,
 "Michael S. Tsirkin" <mst@redhat.com>
To: Stephen Hemminger <stephen@networkplumber.org>
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2015-10-21 08:47, Stephen Hemminger:
> On Wed, 21 Oct 2015 09:38:37 +0000
> "Ananyev, Konstantin" <konstantin.ananyev@intel.com> wrote:
> > I also don't understand what's wrong with using 'always_inline' here.
> > As I understand the author wants compiler to *always inline* that function.
> > So seems perfectly ok to use it here.
> > As I remember just 'inline' is sort of recommendation that compiler is free to ignore.
> > Konstantin 
> 
> I follow Linux/Linus advice and resist the urge to add strong inlining.
> The compiler does a good job of deciding to inline, and many times
> the reason it chooses for not inlining are quite good like:
>   - the code is on an unlikely branch
>   - register pressure means inlining would mean the code would be worse
> 
> Therefore my rules are:
>   * only use inline for small functions. Let compiler decide on larger static funcs
>   * write code where most functions are static (localized scope) where compiler
>     can decide
>   * reserve always inline for things that access hardware and would break if not inlined.

It would be interesting to do some benchmarks with/without "always" keyword
and add these rules in the coding style guide.