[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Wed, 10 Oct 2018 13:54:33 -0500
From: Segher Boessenkool <segher@...nel.crashing.org>
To: Borislav Petkov <bp@...en8.de>
Cc: Ingo Molnar <mingo@...nel.org>, Richard Biener <rguenther@...e.de>,
Michael Matz <matz@...e.de>, gcc@....gnu.org,
Nadav Amit <namit@...are.com>, Ingo Molnar <mingo@...hat.com>,
linux-kernel@...r.kernel.org, x86@...nel.org,
Masahiro Yamada <yamada.masahiro@...ionext.com>,
Sam Ravnborg <sam@...nborg.org>,
Alok Kataria <akataria@...are.com>,
Christopher Li <sparse@...isli.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
"H. Peter Anvin" <hpa@...or.com>, Jan Beulich <JBeulich@...e.com>,
Josh Poimboeuf <jpoimboe@...hat.com>,
Juergen Gross <jgross@...e.com>,
Kate Stewart <kstewart@...uxfoundation.org>,
Kees Cook <keescook@...omium.org>,
linux-sparse@...r.kernel.org,
Peter Zijlstra <peterz@...radead.org>,
Philippe Ombredanne <pombredanne@...b.com>,
Thomas Gleixner <tglx@...utronix.de>,
virtualization@...ts.linux-foundation.org,
Linus Torvalds <torvalds@...ux-foundation.org>,
Chris Zankel <chris@...kel.net>,
Max Filippov <jcmvbkbc@...il.com>,
linux-xtensa@...ux-xtensa.org,
Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: PROPOSAL: Extend inline asm syntax with size spec
On Wed, Oct 10, 2018 at 10:19:06AM +0200, Borislav Petkov wrote:
> On Wed, Oct 10, 2018 at 03:03:25AM -0500, Segher Boessenkool wrote:
> > The code immediately after this makes it size 1, even for things like
> > asm(""), I suppose this works better for the inliner. But that's a detail
> > (and it might change); the description says "consider this asm as minimum
> > length and cost for inlining decisions", which works for either 0 or 1.
>
> Thanks for implementing this, much appreciated. If you need people to
> test stuff, lemme know.
It would be great to hear from kernel people if it works adequately for
what you guys want it for :-)
> > You can think of it as meaning "we want this asm inlined always", and then
> > whether that actually happens depends on if the function around it is
> > inlined or not.
>
> My only concern is how we would catch the other extremity where the
> inline asm grows too big and we end up inlining it everywhere and thus
> getting fat. The 0day bot already builds tinyconfigs but we should be
> looking at vmlinux size growth too.
But this isn't really different from other always_inline concerns afaics?
So you should be able to catch it the same way, too.
Segher
Powered by blists - more mailing lists