From: Peter Zijlstra <peterz@infradead.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Juri Lelli <juri.lelli@gmail.com>,
tglx@linutronix.de, mingo@redhat.com, rostedt@goodmis.org,
oleg@redhat.com, fweisbec@gmail.com, darren@dvhart.com,
johan.eker@ericsson.com, p.faure@akatech.ch,
linux-kernel@vger.kernel.org, claudio@evidence.eu.com,
michael@amarulasolutions.com, fchecconi@gmail.com,
tommaso.cucinotta@sssup.it, nicola.manica@disi.unitn.it,
luca.abeni@unitn.it, dhaval.giani@gmail.com, hgu1972@gmail.com,
paulmck@linux.vnet.ibm.com, raistlin@linux.it,
insop.song@ericsson.com, liming.wang@windriver.com,
jkacur@redhat.com, harald.gustafsson@ericsson.com,
vincent.guittot@linaro.org, Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH 01/16] math128: Introduce various 128bit primitives
Date: Thu, 25 Oct 2012 15:38:09 +0200 [thread overview]
Message-ID: <1351172289.12171.4.camel@twins> (raw)
In-Reply-To: <CAMuHMdXUg-gzTD1NyBH=cfreg8vqN-dDpVGiEkj_pkS-4a1odg@mail.gmail.com>
On Thu, 2012-10-25 at 07:21 +0200, Geert Uytterhoeven wrote:
> On Wed, Oct 24, 2012 at 11:53 PM, Juri Lelli <juri.lelli@gmail.com> wrote:
> > +#ifdef __SIZEOF_INT128__ /* gcc-4.6+ */
> > + unsigned __int128 val;
> > +#endif
>
> So the definition of val depends on (gcc) __SIZEOF_INT128__...
>
> > +/*
> > + * Make usage of __int128 dependent on arch code so they can
> > + * judge if gcc is doing the right thing for them and can over-ride
> > + * any funnies.
> > + */
> > +
> > +#ifndef ARCH_HAS_INT128
>
> ... but all generic users depend on (Kconfig) ARCH_HAS_INT128?
Ah, you're saying both should depend on the same thing. I fear there's a
chicken-egg problem in the code as it is now, the asm/math128.h thing
needs the data structure but is also the one setting ARCH_HAS_INT128.
So its not Kconfig.
> How can Kconfig know if gcc supports this?
It cannot, its per the asm/math128.h header to opt-in on using it. This
so archs can make sure gcc doesn't generate broken code or relies on
libgcc for its __int128 implementation.
Now, if we do as Linus suggests and push the data structure definition
into a separate header we could possibly avoid this.
next prev parent reply other threads:[~2012-10-25 13:39 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-24 21:53 [RFC][PATCH 00/16] sched: SCHED_DEADLINE v6 Juri Lelli
2012-10-24 21:53 ` [PATCH 01/16] math128: Introduce various 128bit primitives Juri Lelli
2012-10-24 22:48 ` Juri Lelli
2012-10-24 23:18 ` Linus Torvalds
2012-10-25 0:08 ` Steven Rostedt
2012-10-25 0:09 ` Linus Torvalds
2012-10-25 13:47 ` Peter Zijlstra
2012-10-25 14:13 ` Peter Zijlstra
2012-10-25 22:26 ` Linus Torvalds
2012-10-26 8:49 ` Peter Zijlstra
2012-10-26 9:24 ` Ingo Molnar
2012-10-26 9:35 ` Peter Zijlstra
2012-10-26 9:42 ` Ingo Molnar
2012-10-26 9:54 ` Peter Zijlstra
2012-10-26 10:04 ` Ingo Molnar
2012-10-26 10:36 ` Thomas Gleixner
2012-10-26 10:44 ` Peter Zijlstra
2012-10-26 11:11 ` Ingo Molnar
2012-10-26 12:56 ` Peter Zijlstra
2012-10-26 18:12 ` Juri Lelli
2012-10-26 18:28 ` Steven Rostedt
2012-10-26 18:34 ` Thomas Gleixner
2012-10-26 18:41 ` Juri Lelli
2012-10-26 12:39 ` Steven Rostedt
2012-10-26 13:09 ` Steven Rostedt
2012-10-26 9:52 ` Harald Gustafsson
2012-10-26 15:17 ` Linus Torvalds
2012-10-25 5:21 ` Geert Uytterhoeven
2012-10-25 13:38 ` Peter Zijlstra [this message]
2012-10-24 21:53 ` [PATCH 02/16] math128, x86_64: Implement {mul,add}_u128 in 64bit asm Juri Lelli
2012-10-24 22:27 ` H. Peter Anvin
2012-10-24 22:47 ` Juri Lelli
2012-10-24 22:51 ` H. Peter Anvin
2012-10-24 21:53 ` [PATCH 03/16] sched: add sched_class->task_dead Juri Lelli
2012-10-24 21:53 ` [PATCH 04/16] sched: add extended scheduling interface Juri Lelli
2012-10-24 21:53 ` [PATCH 05/16] sched: SCHED_DEADLINE structures & implementation Juri Lelli
2012-10-24 21:53 ` [PATCH 06/16] sched: SCHED_DEADLINE SMP-related data structures & logic Juri Lelli
2012-10-24 21:53 ` [PATCH 07/16] sched: SCHED_DEADLINE avg_update accounting Juri Lelli
2012-10-24 21:53 ` [PATCH 08/16] sched: add period support for -deadline tasks Juri Lelli
2012-10-24 21:53 ` [PATCH 09/16] sched: add schedstats " Juri Lelli
2012-10-24 21:53 ` [PATCH 10/16] sched: add latency tracing " Juri Lelli
2012-10-24 21:53 ` [PATCH 11/16] rtmutex: turn the plist into an rb-tree Juri Lelli
2012-10-24 21:53 ` [PATCH 12/16] sched: drafted deadline inheritance logic Juri Lelli
2012-10-24 21:53 ` [PATCH 13/16] sched: add bandwidth management for sched_dl Juri Lelli
2012-10-24 21:53 ` [PATCH 14/16] sched: make dl_bw a sub-quota of rt_bw Juri Lelli
2012-10-24 21:53 ` [PATCH 15/16] sched: speed up -dl pushes with a push-heap Juri Lelli
2012-10-24 21:53 ` [PATCH 16/16] sched: add sched_dl documentation Juri Lelli
2012-10-25 7:18 ` [RFC][PATCH 00/16] sched: SCHED_DEADLINE v6 Ingo Molnar
2012-10-25 9:53 ` Borislav Petkov
2012-10-25 16:58 ` Juri Lelli
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1351172289.12171.4.camel@twins \
--to=peterz@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=claudio@evidence.eu.com \
--cc=darren@dvhart.com \
--cc=dhaval.giani@gmail.com \
--cc=fchecconi@gmail.com \
--cc=fweisbec@gmail.com \
--cc=geert@linux-m68k.org \
--cc=harald.gustafsson@ericsson.com \
--cc=hgu1972@gmail.com \
--cc=insop.song@ericsson.com \
--cc=jkacur@redhat.com \
--cc=johan.eker@ericsson.com \
--cc=juri.lelli@gmail.com \
--cc=liming.wang@windriver.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luca.abeni@unitn.it \
--cc=michael@amarulasolutions.com \
--cc=mingo@kernel.org \
--cc=mingo@redhat.com \
--cc=nicola.manica@disi.unitn.it \
--cc=oleg@redhat.com \
--cc=p.faure@akatech.ch \
--cc=paulmck@linux.vnet.ibm.com \
--cc=raistlin@linux.it \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=tommaso.cucinotta@sssup.it \
--cc=torvalds@linux-foundation.org \
--cc=vincent.guittot@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox