Re: [PATCH 2/3] iommu/iova: don't disable preempt around this_cpu_ptr()

From	Joerg Roedel <joro@8bytes.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH 2/3] iommu/iova: don't disable preempt around this_cpu_ptr()
Date	2017-06-28 12:30 +0200
Message-ID	<tXioq-5z2-21@gated-at.bofh.it> (permalink)
References	<tX1nz-2Ys-11@gated-at.bofh.it> <tX1nA-2Ys-31@gated-at.bofh.it> <tXhsm-50j-37@gated-at.bofh.it> <tXhC3-53u-37@gated-at.bofh.it>
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On Wed, Jun 28, 2017 at 11:31:55AM +0200, Sebastian Andrzej Siewior wrote:
> It really does. The spin_lock() does disable preemption but this is not
> the problem. The thing is that the preempt_disable() is superfluous and
> it hurts Preempt-RT (and this is how I noticed it). Also the
> get_cpu_ptr() is not requited and was only added to keep lockdep quiet
> (according to the history).
> Everything else here can stay as-is, I am just asking for the removal of
> the redundant preempt_disable() where it is not required.

Okay, makes sense, I applied both patches.


Thanks,

	Joerg

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[PATCH 2/3] iommu/iova: don't disable preempt around this_cpu_ptr() Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2017-06-27 18:20 +0200
  Re: [PATCH 2/3] iommu/iova: don't disable preempt around  this_cpu_ptr() Joerg Roedel <joro@8bytes.org> - 2017-06-28 11:30 +0200
    Re: [PATCH 2/3] iommu/iova: don't disable preempt around  this_cpu_ptr() Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2017-06-28 11:40 +0200
      Re: [PATCH 2/3] iommu/iova: don't disable preempt around  this_cpu_ptr() Joerg Roedel <joro@8bytes.org> - 2017-06-28 12:30 +0200

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