From: Tejun Heo <tj@kernel.org>
To: Christoph Lameter <cl@gentwo.org>
Cc: linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH 02/12] percpu: introduce arch_raw_cpu_ptr()
Date: Fri, 13 Jun 2014 14:24:17 -0400 [thread overview]
Message-ID: <20140613182417.GA3723@htj.dyndns.org> (raw)
In-Reply-To: <alpine.DEB.2.10.1406131209540.1717@gentwo.org>
On Fri, Jun 13, 2014 at 12:10:36PM -0500, Christoph Lameter wrote:
> On Thu, 12 Jun 2014, Tejun Heo wrote:
>
> > Currently, archs can override raw_cpu_ptr() directly; however, we
> > wanna build a layer of indirection in the generic part of percpu so
> > that we can implement generic features there without affecting archs.
>
> Not sure why one would do this. We already have this_cpu_ptr() (arch
> independant) and the lower level raw_cpu_ptr() which can be modified by
> the arch code.
So that there's separate between generic part of definition and
arch-specific part. This allows the generic portion of definition to
be handled in the generic code. e.g. arch no longer has to worry
about verifying arguments or having a data dependency barrier. It
just has to worry about the core implementation. The generic layer
can handle the boilerplates.
Thanks.
--
tejun
next prev parent reply other threads:[~2014-06-13 18:24 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-12 16:23 [PATCHSET percpu/for-3.17] percpu: clean up percpu accessor and operation definitions Tejun Heo
2014-06-12 16:23 ` [PATCH 01/12] percpu: disallow archs from overriding SHIFT_PERCPU_PTR() Tejun Heo
2014-06-13 1:58 ` Christoph Lameter
2014-06-12 16:23 ` [PATCH 02/12] percpu: introduce arch_raw_cpu_ptr() Tejun Heo
2014-06-13 17:10 ` Christoph Lameter
2014-06-13 18:24 ` Tejun Heo [this message]
2014-06-12 16:23 ` [PATCH 03/12] percpu: include/asm-generic/percpu.h should contain only arch-overridable parts Tejun Heo
2014-06-13 17:12 ` Christoph Lameter
2014-06-12 16:23 ` [PATCH 04/12] percpu: move accessors from include/linux/percpu.h to percpu-defs.h Tejun Heo
2014-06-13 17:13 ` Christoph Lameter
2014-06-12 16:23 ` [PATCH 05/12] percpu: reorganize include/linux/percpu-defs.h Tejun Heo
2014-06-13 17:16 ` Christoph Lameter
2014-06-13 18:25 ` Tejun Heo
2014-06-13 18:55 ` Christoph Lameter
2014-06-16 15:31 ` Christoph Lameter
2014-06-18 18:16 ` Tejun Heo
2014-06-19 21:07 ` Christoph Lameter
2014-06-12 16:23 ` [PATCH 06/12] percpu: only allow sized arch overrides for {raw|this}_cpu_*() ops Tejun Heo
2014-06-13 17:18 ` Christoph Lameter
2014-06-12 16:23 ` [PATCH 07/12] percpu: move generic {raw|this}_cpu_*_N() definitions to include/asm-generic/percpu.h Tejun Heo
2014-06-13 17:19 ` Christoph Lameter
2014-06-12 16:23 ` [PATCH 08/12] percpu: move {raw|this}_cpu_*() definitions to include/linux/percpu-defs.h Tejun Heo
2014-06-13 17:20 ` Christoph Lameter
2014-06-12 16:23 ` [PATCH 09/12] percpu: reorder macros in percpu header files Tejun Heo
2014-06-13 17:21 ` Christoph Lameter
2014-06-12 16:23 ` [PATCH 10/12] percpu: use raw_cpu_*() to define __this_cpu_*() Tejun Heo
2014-06-13 17:22 ` Christoph Lameter
2014-06-12 16:23 ` [PATCH 11/12] percpu: preffity percpu header files Tejun Heo
2014-06-13 17:23 ` Christoph Lameter
2014-06-12 16:23 ` [PATCH 12/12] percpu: invoke __verify_pcpu_ptr() from the generic part of accessors and operations Tejun Heo
2014-06-17 23:20 ` [PATCH UPDATED " Tejun Heo
2014-06-17 23:22 ` [PATCHSET percpu/for-3.17] percpu: clean up percpu accessor and operation definitions Tejun Heo
2014-06-19 21:05 ` Christoph Lameter
2014-06-19 21:09 ` Tejun Heo
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