linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Daniel Vetter <daniel@ffwll.ch>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Daniel Vetter <daniel.vetter@intel.com>,
	Intel Graphics Development <intel-gfx@lists.freedesktop.org>,
	LKML <linux-kernel@vger.kernel.org>,
	DRI Development <dri-devel@lists.freedesktop.org>
Subject: Re: [Intel-gfx] [PATCH 11/12] sched: use for_each_if in topology.h
Date: Mon, 9 Jul 2018 19:55:20 +0200	[thread overview]
Message-ID: <CAKMK7uHQz6+=30nCU-8CerC9eRrwnA_O-cxRSoHHbGf0uNMYmA@mail.gmail.com> (raw)
In-Reply-To: <20180709161232.up6vnuybvkxn76am@lakrids.cambridge.arm.com>

On Mon, Jul 9, 2018 at 6:12 PM, Mark Rutland <mark.rutland@arm.com> wrote:
> On Mon, Jul 09, 2018 at 06:03:42PM +0200, Peter Zijlstra wrote:
>> On Mon, Jul 09, 2018 at 05:52:04PM +0200, Daniel Vetter wrote:
>> > for_each_something(foo)
>> >     if (foo->bla)
>> >             call_bla(foo);
>> >     else
>> >             call_default(foo);
>> >
>> > Totally contrived, but this complains. Liberally sprinkling {} also shuts
>> > up the compiler, but it's a bit confusing given that a plain for {;;} is
>> > totally fine. And it's confusing since at first glance the compiler
>> > complaining about nested if and ambigous else doesn't make sense since
>> > clearly there's only 1 if there.
>>
>> Ah, so the pattern the compiler tries to warn about is:
>>
>>       if (foo)
>>               if (bar)
>>                       /* stmts1 */
>>               else
>>                       /* stmts2 *
>>
>> Because it might not be immediately obvious with which if the else goes.
>> Which is fair enough I suppose.
>>
>> OK, ACK.
>
> Just to bikeshed, there could be macros other than for_each_*() macros
> that will want to use this internally, so perhaps it would be worth the
> generic version being named something like if_noelse().
>
> We could always add that as/when required, though.

I think a better name would be really good, but both when we added it
for i915 and when we move it to drm headers we drew a blank.
if_noelse() describes pretty good what it does, but kinda fails on the
"where should I use it" departement. If there's some consensus I can
sed the patches quickly.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

  reply	other threads:[~2018-07-09 17:55 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-09  8:36 [PATCH 01/12] kernel.h: Add for_each_if() Daniel Vetter
2018-07-09  8:36 ` [PATCH 02/12] blk: use for_each_if Daniel Vetter
2018-07-11 16:40   ` Tejun Heo
2018-07-11 16:45     ` Tejun Heo
2018-07-11 18:30       ` Jens Axboe
2018-07-11 18:50         ` Daniel Vetter
2018-07-11 19:31           ` Jens Axboe
2018-07-11 20:06             ` Tejun Heo
2018-07-11 21:08               ` Daniel Vetter
2018-07-11 21:13                 ` Jens Axboe
2018-07-12  6:41                   ` Daniel Vetter
2018-07-12  6:45           ` Joe Perches
2018-07-12 13:54             ` Jens Axboe
2018-07-12 15:32               ` Joe Perches
2018-07-13  9:28             ` Vlastimil Babka
2018-07-09  8:36 ` [PATCH 03/12] cgroup: " Daniel Vetter
2018-07-11 16:46   ` Tejun Heo
2018-07-09  8:36 ` [PATCH 04/12] cpufreq: " Daniel Vetter
2018-07-09  9:28   ` Eric Engestrom
2018-07-09 16:11   ` [PATCH] " Daniel Vetter
2018-07-09 21:36     ` Rafael J. Wysocki
2018-07-09  8:36 ` [PATCH 05/12] dmar: Use for_each_If Daniel Vetter
2018-07-20 12:50   ` Joerg Roedel
2018-07-09  8:36 ` [PATCH 06/12] mm: use for_each_if Daniel Vetter
2018-07-09 18:00   ` Pavel Tatashin
2018-07-09  8:36 ` [PATCH 07/12] ide: " Daniel Vetter
2018-07-09  8:36 ` [PATCH 08/12] netdev: " Daniel Vetter
2018-07-09  8:36 ` [PATCH 09/12] nubus: " Daniel Vetter
2018-07-09 10:17   ` Finn Thain
2018-07-17 15:26   ` Geert Uytterhoeven
2018-07-09  8:36 ` [PATCH 10/12] pci: " Daniel Vetter
2018-07-09 22:48   ` Bjorn Helgaas
2018-07-09  8:36 ` [PATCH 11/12] sched: use for_each_if in topology.h Daniel Vetter
2018-07-09 10:36   ` Peter Zijlstra
2018-07-09 15:00     ` Daniel Vetter
2018-07-09 15:12       ` Peter Zijlstra
2018-07-09 15:52         ` Daniel Vetter
2018-07-09 16:03           ` Peter Zijlstra
2018-07-09 16:06             ` Daniel Vetter
2018-07-09 16:12             ` Mark Rutland
2018-07-09 17:55               ` Daniel Vetter [this message]
2018-07-11 16:51                 ` [Intel-gfx] " Mark Rutland
2018-07-09 16:30           ` Peter Zijlstra
2018-07-09  8:36 ` [PATCH 12/12] usb: use for_each_if Daniel Vetter
2018-07-09 11:50 ` [PATCH 01/12] kernel.h: Add for_each_if() Andy Shevchenko
2018-07-09 16:25 ` [PATCH] " Daniel Vetter
2018-07-09 18:30   ` Andy Shevchenko
2018-07-09 23:30   ` Andrew Morton
2018-07-10  7:53     ` Daniel Vetter
2018-07-10 10:32       ` NeilBrown
2018-07-11 11:51         ` Daniel Vetter
2018-07-11 23:05           ` Andrew Morton
2018-07-12  6:39             ` Daniel Vetter
2018-07-13 23:37             ` NeilBrown
2018-07-13 23:42               ` Randy Dunlap
2018-07-16  8:11                 ` Andy Shevchenko
2018-07-16 15:41                   ` Randy Dunlap
2018-07-16 22:16                   ` NeilBrown

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='CAKMK7uHQz6+=30nCU-8CerC9eRrwnA_O-cxRSoHHbGf0uNMYmA@mail.gmail.com' \
    --to=daniel@ffwll.ch \
    --cc=akpm@linux-foundation.org \
    --cc=daniel.vetter@intel.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=intel-gfx@lists.freedesktop.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=peterz@infradead.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;
as well as URLs for NNTP newsgroup(s).