From: Peter Zijlstra <peterz@infradead.org>
To: Davidlohr Bueso <dave@stgolabs.net>
Cc: mingo@kernel.org, davem@davemloft.net, cw00.choi@samsung.com,
dougthompson@xmission.com, bp@alien8.de, mchehab@osg.samsung.com,
gregkh@linuxfoundation.org, pfg@sgi.com, jikos@kernel.org,
hans.verkuil@cisco.com, awalls@md.metrocast.net,
dledford@redhat.com, sean.hefty@intel.com, kys@microsoft.com,
heiko.carstens@de.ibm.com, James.Bottomley@HansenPartnership.com,
sumit.semwal@linaro.org, schwidefsky@de.ibm.com,
linux-kernel@vger.kernel.org, Davidlohr Bueso <dbueso@suse.de>
Subject: Re: [PATCH v2 01/12] locking/atomic: Introduce inc/dec calls for FETCH-OP flavors
Date: Fri, 24 Jun 2016 20:48:57 +0200 [thread overview]
Message-ID: <20160624184857.GD30154@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20160624163430.GA11823@linux-80c1.suse>
On Fri, Jun 24, 2016 at 09:34:30AM -0700, Davidlohr Bueso wrote:
> On Thu, 23 Jun 2016, Peter Zijlstra wrote:
>
> >-
> >/* atomic_fetch_inc_relaxed */
> >#ifndef atomic_fetch_inc_relaxed
> >+
> >+#ifndef atomic_fetch_inc
>
> #define atomic_fetch_inc(v) (atomic_fetch_add(1, v))
Ah yes.
> >+#define atomic_fetch_inc_relaxed(v) atomic_fetch_add_relaxed(1, (v))
> >+#define atomic_fetch_inc_acquire(v) atomic_fetch_add_acquire(1, (v))
> >+#define atomic_fetch_inc_release(v) atomic_fetch_add_release(1, (v))
>
> I was under the impression that if the archs don't define their own calls,
> then we always default to fully ordered. Which is why I based all this ifdefery
> on what is currently done with the other atomic_fetch_$ops.
Right, but this allows an arch to only define atomic_fetch_add_relaxed()
and have the various forms of fetch_inc() instantiated as well.
With your earlier version they would all fall back to the fully
sequential variant of fetch_add().
next prev parent reply other threads:[~2016-06-24 18:49 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-20 20:05 [PATCH -tip 00/12] locking/atomics: Add and use inc,dec calls for FETCH-OP flavors Davidlohr Bueso
2016-06-20 20:05 ` [PATCH 01/12] locking/atomic: Introduce inc/dec " Davidlohr Bueso
2016-06-21 7:28 ` Peter Zijlstra
2016-06-21 13:33 ` [PATCH v2 " Davidlohr Bueso
2016-06-21 16:36 ` Davidlohr Bueso
2016-06-23 9:09 ` Peter Zijlstra
2016-06-24 16:34 ` Davidlohr Bueso
2016-06-24 18:48 ` Peter Zijlstra [this message]
2016-06-28 21:56 ` [PATCH -v4 " Davidlohr Bueso
2016-07-07 8:33 ` [tip:locking/core] locking/atomic: Introduce inc/dec variants for the atomic_fetch_$op() API tip-bot for Davidlohr Bueso
2016-06-20 20:05 ` [PATCH 02/12] net/neighbour: Employ atomic_fetch_inc() Davidlohr Bueso
2016-06-20 20:05 ` [PATCH 03/12] PM,devfreq: " Davidlohr Bueso
2016-07-02 5:04 ` Chanwoo Choi
2016-06-20 20:05 ` [PATCH 04/12] EDAC: " Davidlohr Bueso
2016-06-21 13:59 ` Borislav Petkov
2016-06-20 20:05 ` [PATCH 05/12] tty/serial: " Davidlohr Bueso
2016-06-20 20:05 ` [PATCH 06/12] HID,wacom: " Davidlohr Bueso
2016-06-22 8:10 ` Jiri Kosina
2016-06-20 20:05 ` [PATCH 07/12] drivers/media: " Davidlohr Bueso
2016-07-13 16:07 ` Mauro Carvalho Chehab
2016-06-20 20:06 ` [PATCH 08/12] infiniband: " Davidlohr Bueso
2016-06-20 20:06 ` [PATCH 09/12] drivers/hv: " Davidlohr Bueso
2016-06-20 20:06 ` [PATCH 10/12] s390/scm_block: " Davidlohr Bueso
2016-06-20 20:06 ` [PATCH 11/12] scsi: " Davidlohr Bueso
2016-06-20 20:06 ` [PATCH 12/12] dma-buf/fence: Employ atomic_fetch_add Davidlohr Bueso
2016-06-24 16:46 ` [PATCH -tip 00/12] locking/atomics: Add and use inc,dec calls for FETCH-OP flavors James Bottomley
2016-06-24 17:30 ` Davidlohr Bueso
2016-06-24 17:44 ` James Bottomley
2016-06-24 20:35 ` Davidlohr Bueso
2016-06-24 17:45 ` KY Srinivasan
2016-06-24 19:35 ` Davidlohr Bueso
2016-06-24 19:17 ` Peter Zijlstra
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