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
next prev parent 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
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