Re: [PATCH] percpu: improve generic percpu modify-return implementation

From	Tejun Heo <tj@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH] percpu: improve generic percpu modify-return implementation
Date	2016-09-22 18:10 +0200
Message-ID	<skeJs-7S-27@gated-at.bofh.it> (permalink)
References	<sjLxM-6M9-23@gated-at.bofh.it> <sjNpT-7ZV-13@gated-at.bofh.it> <sjQH7-1Hi-15@gated-at.bofh.it> <sk4h3-1NV-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Hello,

On Thu, Sep 22, 2016 at 02:35:00PM +1000, Nicholas Piggin wrote:
> Well thank you, how about you?

Heh, can't complain.  Hope to see you around sometime.  It's been
forever.

> Trying a new mail client, sorry. It *seems* to be working now, how's
> this?

Hmm... Still encoded.

> From d0cb9052d6f4c31d24f999b7b0cecb34681eee9b Mon Sep 17 00:00:00 2001
> From: Nicholas Piggin <npiggin@gmail.com>
> Date: Wed, 21 Sep 2016 18:23:43 +1000
> Subject: [PATCH] percpu: improve generic percpu modify-return implementations
> 
> Some architectures require an additional load to find the address of
> percpu pointers. In some implemenatations, the C aliasing rules do not
> allow the result of that load to be kept over the store that modifies
> the percpu variable, which causes additional loads.
> 
> Work around this by finding the pointer first, then operating on that.
> 
> It's also possible to mark things as restrict and those kind of games,
> but that can require larger and arch specific changes.

QP-decoded and applied to percpu/for-4.9.

Thanks.

-- 
tejun

Thread

[PATCH] percpu: improve generic percpu modify-return implementation Nicholas Piggin <npiggin@gmail.com> - 2016-09-21 11:00 +0200
  Re: [PATCH] percpu: improve generic percpu modify-return  implementation kbuild test robot <lkp@intel.com> - 2016-09-21 12:30 +0200
  Re: [PATCH] percpu: improve generic percpu modify-return  implementation kbuild test robot <lkp@intel.com> - 2016-09-21 12:40 +0200
  Re: [PATCH] percpu: improve generic percpu modify-return  implementation Nicholas Piggin <npiggin@gmail.com> - 2016-09-21 13:00 +0200
    Re: [PATCH] percpu: improve generic percpu modify-return  implementation Tejun Heo <tj@kernel.org> - 2016-09-21 16:30 +0200
      Re: [PATCH] percpu: improve generic percpu modify-return  implementation Christoph Lameter <cl@linux.com> - 2016-09-21 22:20 +0200
        Re: [PATCH] percpu: improve generic percpu modify-return  implementation Nicholas Piggin <npiggin@gmail.com> - 2016-09-22 06:50 +0200
      Re: [PATCH] percpu: improve generic percpu modify-return  implementation Nicholas Piggin <npiggin@gmail.com> - 2016-09-22 07:00 +0200
        Re: [PATCH] percpu: improve generic percpu modify-return  implementation Tejun Heo <tj@kernel.org> - 2016-09-22 18:10 +0200
          Re: [PATCH] percpu: improve generic percpu modify-return  implementation Nicholas Piggin <npiggin@gmail.com> - 2016-09-23 09:40 +0200

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