From: dv@vollmann.ch (Detlef Vollmann)
To: linux-arm-kernel@lists.infradead.org
Subject: Why don't we have atomic_set_mask()?
Date: Thu, 17 Mar 2011 14:25:05 +0100 [thread overview]
Message-ID: <4D820BB1.9050500@vollmann.ch> (raw)
In-Reply-To: <20110317120748.GH29758@n2100.arm.linux.org.uk>
On 03/17/11 13:07, Russell King - ARM Linux wrote:
> On Thu, Mar 17, 2011 at 08:36:15PM +0900, KyongHo Cho wrote:
>> arch/arm/asm/atomic.h defines atomic_clear_mask() but its counterpart,
>> atomic_set_mask() is not defined.
>
> Nothing other than some s390 drivers seems to use it, so I'd say no.
> I also feel that atomic_xxx() is over-used, many times in inappropriate
> and buggy ways.
I fully agree. Simply asking for a atomic_set_mask looks like you're
trying to do something wrong.
The convention is to use those bits as flags, and having the contention
on setting the flag, so you have test_and_set_bit(), and can then
deal with the case where the flag was already set.
Doing that with more than one flag at a time would get pretty complex.
Detlef
next prev parent reply other threads:[~2011-03-17 13:25 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-17 11:36 Why don't we have atomic_set_mask()? KyongHo Cho
2011-03-17 12:07 ` Russell King - ARM Linux
2011-03-17 13:25 ` Detlef Vollmann [this message]
2011-03-17 12:09 ` Russell King - ARM Linux
2011-03-17 12:24 ` KyongHo Cho
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