<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/tile/kernel/smpboot.c, branch v4.11</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>sched/headers: Move task-&gt;mm handling methods to &lt;linux/sched/mm.h&gt;</title>
<updated>2017-03-03T00:43:28+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2017-02-01T18:08:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=68e21be2916b359fd8afb536c1911dc014cfd03e'/>
<id>68e21be2916b359fd8afb536c1911dc014cfd03e</id>
<content type='text'>
Move the following task-&gt;mm helper APIs into a new header file,
&lt;linux/sched/mm.h&gt;, to further reduce the size and complexity
of &lt;linux/sched.h&gt;.

Here are how the APIs are used in various kernel files:

  # mm_alloc():
  arch/arm/mach-rpc/ecard.c
  fs/exec.c
  include/linux/sched/mm.h
  kernel/fork.c

  # __mmdrop():
  arch/arc/include/asm/mmu_context.h
  include/linux/sched/mm.h
  kernel/fork.c

  # mmdrop():
  arch/arm/mach-rpc/ecard.c
  arch/m68k/sun3/mmu_emu.c
  arch/x86/mm/tlb.c
  drivers/gpu/drm/amd/amdkfd/kfd_process.c
  drivers/gpu/drm/i915/i915_gem_userptr.c
  drivers/infiniband/hw/hfi1/file_ops.c
  drivers/vfio/vfio_iommu_spapr_tce.c
  fs/exec.c
  fs/proc/base.c
  fs/proc/task_mmu.c
  fs/proc/task_nommu.c
  fs/userfaultfd.c
  include/linux/mmu_notifier.h
  include/linux/sched/mm.h
  kernel/fork.c
  kernel/futex.c
  kernel/sched/core.c
  mm/khugepaged.c
  mm/ksm.c
  mm/mmu_context.c
  mm/mmu_notifier.c
  mm/oom_kill.c
  virt/kvm/kvm_main.c

  # mmdrop_async_fn():
  include/linux/sched/mm.h

  # mmdrop_async():
  include/linux/sched/mm.h
  kernel/fork.c

  # mmget_not_zero():
  fs/userfaultfd.c
  include/linux/sched/mm.h
  mm/oom_kill.c

  # mmput():
  arch/arc/include/asm/mmu_context.h
  arch/arc/kernel/troubleshoot.c
  arch/frv/mm/mmu-context.c
  arch/powerpc/platforms/cell/spufs/context.c
  arch/sparc/include/asm/mmu_context_32.h
  drivers/android/binder.c
  drivers/gpu/drm/etnaviv/etnaviv_gem.c
  drivers/gpu/drm/i915/i915_gem_userptr.c
  drivers/infiniband/core/umem.c
  drivers/infiniband/core/umem_odp.c
  drivers/infiniband/core/uverbs_main.c
  drivers/infiniband/hw/mlx4/main.c
  drivers/infiniband/hw/mlx5/main.c
  drivers/infiniband/hw/usnic/usnic_uiom.c
  drivers/iommu/amd_iommu_v2.c
  drivers/iommu/intel-svm.c
  drivers/lguest/lguest_user.c
  drivers/misc/cxl/fault.c
  drivers/misc/mic/scif/scif_rma.c
  drivers/oprofile/buffer_sync.c
  drivers/vfio/vfio_iommu_type1.c
  drivers/vhost/vhost.c
  drivers/xen/gntdev.c
  fs/exec.c
  fs/proc/array.c
  fs/proc/base.c
  fs/proc/task_mmu.c
  fs/proc/task_nommu.c
  fs/userfaultfd.c
  include/linux/sched/mm.h
  kernel/cpuset.c
  kernel/events/core.c
  kernel/events/uprobes.c
  kernel/exit.c
  kernel/fork.c
  kernel/ptrace.c
  kernel/sys.c
  kernel/trace/trace_output.c
  kernel/tsacct.c
  mm/memcontrol.c
  mm/memory.c
  mm/mempolicy.c
  mm/migrate.c
  mm/mmu_notifier.c
  mm/nommu.c
  mm/oom_kill.c
  mm/process_vm_access.c
  mm/rmap.c
  mm/swapfile.c
  mm/util.c
  virt/kvm/async_pf.c

  # mmput_async():
  include/linux/sched/mm.h
  kernel/fork.c
  mm/oom_kill.c

  # get_task_mm():
  arch/arc/kernel/troubleshoot.c
  arch/powerpc/platforms/cell/spufs/context.c
  drivers/android/binder.c
  drivers/gpu/drm/etnaviv/etnaviv_gem.c
  drivers/infiniband/core/umem.c
  drivers/infiniband/core/umem_odp.c
  drivers/infiniband/hw/mlx4/main.c
  drivers/infiniband/hw/mlx5/main.c
  drivers/infiniband/hw/usnic/usnic_uiom.c
  drivers/iommu/amd_iommu_v2.c
  drivers/iommu/intel-svm.c
  drivers/lguest/lguest_user.c
  drivers/misc/cxl/fault.c
  drivers/misc/mic/scif/scif_rma.c
  drivers/oprofile/buffer_sync.c
  drivers/vfio/vfio_iommu_type1.c
  drivers/vhost/vhost.c
  drivers/xen/gntdev.c
  fs/proc/array.c
  fs/proc/base.c
  fs/proc/task_mmu.c
  include/linux/sched/mm.h
  kernel/cpuset.c
  kernel/events/core.c
  kernel/exit.c
  kernel/fork.c
  kernel/ptrace.c
  kernel/sys.c
  kernel/trace/trace_output.c
  kernel/tsacct.c
  mm/memcontrol.c
  mm/memory.c
  mm/mempolicy.c
  mm/migrate.c
  mm/mmu_notifier.c
  mm/nommu.c
  mm/util.c

  # mm_access():
  fs/proc/base.c
  include/linux/sched/mm.h
  kernel/fork.c
  mm/process_vm_access.c

  # mm_release():
  arch/arc/include/asm/mmu_context.h
  fs/exec.c
  include/linux/sched/mm.h
  include/uapi/linux/sched.h
  kernel/exit.c
  kernel/fork.c

Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Move the following task-&gt;mm helper APIs into a new header file,
&lt;linux/sched/mm.h&gt;, to further reduce the size and complexity
of &lt;linux/sched.h&gt;.

Here are how the APIs are used in various kernel files:

  # mm_alloc():
  arch/arm/mach-rpc/ecard.c
  fs/exec.c
  include/linux/sched/mm.h
  kernel/fork.c

  # __mmdrop():
  arch/arc/include/asm/mmu_context.h
  include/linux/sched/mm.h
  kernel/fork.c

  # mmdrop():
  arch/arm/mach-rpc/ecard.c
  arch/m68k/sun3/mmu_emu.c
  arch/x86/mm/tlb.c
  drivers/gpu/drm/amd/amdkfd/kfd_process.c
  drivers/gpu/drm/i915/i915_gem_userptr.c
  drivers/infiniband/hw/hfi1/file_ops.c
  drivers/vfio/vfio_iommu_spapr_tce.c
  fs/exec.c
  fs/proc/base.c
  fs/proc/task_mmu.c
  fs/proc/task_nommu.c
  fs/userfaultfd.c
  include/linux/mmu_notifier.h
  include/linux/sched/mm.h
  kernel/fork.c
  kernel/futex.c
  kernel/sched/core.c
  mm/khugepaged.c
  mm/ksm.c
  mm/mmu_context.c
  mm/mmu_notifier.c
  mm/oom_kill.c
  virt/kvm/kvm_main.c

  # mmdrop_async_fn():
  include/linux/sched/mm.h

  # mmdrop_async():
  include/linux/sched/mm.h
  kernel/fork.c

  # mmget_not_zero():
  fs/userfaultfd.c
  include/linux/sched/mm.h
  mm/oom_kill.c

  # mmput():
  arch/arc/include/asm/mmu_context.h
  arch/arc/kernel/troubleshoot.c
  arch/frv/mm/mmu-context.c
  arch/powerpc/platforms/cell/spufs/context.c
  arch/sparc/include/asm/mmu_context_32.h
  drivers/android/binder.c
  drivers/gpu/drm/etnaviv/etnaviv_gem.c
  drivers/gpu/drm/i915/i915_gem_userptr.c
  drivers/infiniband/core/umem.c
  drivers/infiniband/core/umem_odp.c
  drivers/infiniband/core/uverbs_main.c
  drivers/infiniband/hw/mlx4/main.c
  drivers/infiniband/hw/mlx5/main.c
  drivers/infiniband/hw/usnic/usnic_uiom.c
  drivers/iommu/amd_iommu_v2.c
  drivers/iommu/intel-svm.c
  drivers/lguest/lguest_user.c
  drivers/misc/cxl/fault.c
  drivers/misc/mic/scif/scif_rma.c
  drivers/oprofile/buffer_sync.c
  drivers/vfio/vfio_iommu_type1.c
  drivers/vhost/vhost.c
  drivers/xen/gntdev.c
  fs/exec.c
  fs/proc/array.c
  fs/proc/base.c
  fs/proc/task_mmu.c
  fs/proc/task_nommu.c
  fs/userfaultfd.c
  include/linux/sched/mm.h
  kernel/cpuset.c
  kernel/events/core.c
  kernel/events/uprobes.c
  kernel/exit.c
  kernel/fork.c
  kernel/ptrace.c
  kernel/sys.c
  kernel/trace/trace_output.c
  kernel/tsacct.c
  mm/memcontrol.c
  mm/memory.c
  mm/mempolicy.c
  mm/migrate.c
  mm/mmu_notifier.c
  mm/nommu.c
  mm/oom_kill.c
  mm/process_vm_access.c
  mm/rmap.c
  mm/swapfile.c
  mm/util.c
  virt/kvm/async_pf.c

  # mmput_async():
  include/linux/sched/mm.h
  kernel/fork.c
  mm/oom_kill.c

  # get_task_mm():
  arch/arc/kernel/troubleshoot.c
  arch/powerpc/platforms/cell/spufs/context.c
  drivers/android/binder.c
  drivers/gpu/drm/etnaviv/etnaviv_gem.c
  drivers/infiniband/core/umem.c
  drivers/infiniband/core/umem_odp.c
  drivers/infiniband/hw/mlx4/main.c
  drivers/infiniband/hw/mlx5/main.c
  drivers/infiniband/hw/usnic/usnic_uiom.c
  drivers/iommu/amd_iommu_v2.c
  drivers/iommu/intel-svm.c
  drivers/lguest/lguest_user.c
  drivers/misc/cxl/fault.c
  drivers/misc/mic/scif/scif_rma.c
  drivers/oprofile/buffer_sync.c
  drivers/vfio/vfio_iommu_type1.c
  drivers/vhost/vhost.c
  drivers/xen/gntdev.c
  fs/proc/array.c
  fs/proc/base.c
  fs/proc/task_mmu.c
  include/linux/sched/mm.h
  kernel/cpuset.c
  kernel/events/core.c
  kernel/exit.c
  kernel/fork.c
  kernel/ptrace.c
  kernel/sys.c
  kernel/trace/trace_output.c
  kernel/tsacct.c
  mm/memcontrol.c
  mm/memory.c
  mm/mempolicy.c
  mm/migrate.c
  mm/mmu_notifier.c
  mm/nommu.c
  mm/util.c

  # mm_access():
  fs/proc/base.c
  include/linux/sched/mm.h
  kernel/fork.c
  mm/process_vm_access.c

  # mm_release():
  arch/arc/include/asm/mmu_context.h
  fs/exec.c
  include/linux/sched/mm.h
  include/uapi/linux/sched.h
  kernel/exit.c
  kernel/fork.c

Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>sched/headers: Prepare for new header dependencies before moving code to &lt;linux/sched/task.h&gt;</title>
<updated>2017-03-02T07:42:35+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2017-02-08T17:51:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=299300258d1bc4e997b7db340a2e06636757fe2e'/>
<id>299300258d1bc4e997b7db340a2e06636757fe2e</id>
<content type='text'>
We are going to split &lt;linux/sched/task.h&gt; out of &lt;linux/sched.h&gt;, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder &lt;linux/sched/task.h&gt; file that just
maps to &lt;linux/sched.h&gt; to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We are going to split &lt;linux/sched/task.h&gt; out of &lt;linux/sched.h&gt;, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder &lt;linux/sched/task.h&gt; file that just
maps to &lt;linux/sched.h&gt; to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: add new mmgrab() helper</title>
<updated>2017-02-28T02:43:48+00:00</updated>
<author>
<name>Vegard Nossum</name>
<email>vegard.nossum@oracle.com</email>
</author>
<published>2017-02-27T22:30:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f1f1007644ffc8051a4c11427d58b1967ae7b75a'/>
<id>f1f1007644ffc8051a4c11427d58b1967ae7b75a</id>
<content type='text'>
Apart from adding the helper function itself, the rest of the kernel is
converted mechanically using:

  git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&amp;\(.*\)-&gt;mm_count);/mmgrab\(\1\);/'
  git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&amp;\(.*\)\.mm_count);/mmgrab\(\&amp;\1\);/'

This is needed for a later patch that hooks into the helper, but might
be a worthwhile cleanup on its own.

(Michal Hocko provided most of the kerneldoc comment.)

Link: http://lkml.kernel.org/r/20161218123229.22952-1-vegard.nossum@oracle.com
Signed-off-by: Vegard Nossum &lt;vegard.nossum@oracle.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Apart from adding the helper function itself, the rest of the kernel is
converted mechanically using:

  git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&amp;\(.*\)-&gt;mm_count);/mmgrab\(\1\);/'
  git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&amp;\(.*\)\.mm_count);/mmgrab\(\&amp;\1\);/'

This is needed for a later patch that hooks into the helper, but might
be a worthwhile cleanup on its own.

(Michal Hocko provided most of the kerneldoc comment.)

Link: http://lkml.kernel.org/r/20161218123229.22952-1-vegard.nossum@oracle.com
Signed-off-by: Vegard Nossum &lt;vegard.nossum@oracle.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arch/hotplug: Call into idle with a proper state</title>
<updated>2016-03-01T19:36:57+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2016-02-26T18:43:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fc6d73d67436e7784758a831227bd019547a3f73'/>
<id>fc6d73d67436e7784758a831227bd019547a3f73</id>
<content type='text'>
Let the non boot cpus call into idle with the corresponding hotplug state, so
the hotplug core can handle the further bringup. That's a first step to
convert the boot side of the hotplugged cpus to do all the synchronization
with the other side through the state machine. For now it'll only start the
hotplug thread and kick the full bringup of the cpu.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-arch@vger.kernel.org
Cc: Rik van Riel &lt;riel@redhat.com&gt;
Cc: Rafael Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Cc: "Srivatsa S. Bhat" &lt;srivatsa@mit.edu&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Arjan van de Ven &lt;arjan@linux.intel.com&gt;
Cc: Sebastian Siewior &lt;bigeasy@linutronix.de&gt;
Cc: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Paul McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Paul Turner &lt;pjt@google.com&gt;
Link: http://lkml.kernel.org/r/20160226182341.614102639@linutronix.de
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Let the non boot cpus call into idle with the corresponding hotplug state, so
the hotplug core can handle the further bringup. That's a first step to
convert the boot side of the hotplugged cpus to do all the synchronization
with the other side through the state machine. For now it'll only start the
hotplug thread and kick the full bringup of the cpu.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-arch@vger.kernel.org
Cc: Rik van Riel &lt;riel@redhat.com&gt;
Cc: Rafael Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Cc: "Srivatsa S. Bhat" &lt;srivatsa@mit.edu&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Arjan van de Ven &lt;arjan@linux.intel.com&gt;
Cc: Sebastian Siewior &lt;bigeasy@linutronix.de&gt;
Cc: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Paul McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Paul Turner &lt;pjt@google.com&gt;
Link: http://lkml.kernel.org/r/20160226182341.614102639@linutronix.de
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tile: Use the more common pr_warn instead of pr_warning</title>
<updated>2014-11-11T20:51:42+00:00</updated>
<author>
<name>Joe Perches</name>
<email>joe@perches.com</email>
</author>
<published>2014-10-31T17:50:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f47436734dc89ece62654d4db8d08163a89dd7ca'/>
<id>f47436734dc89ece62654d4db8d08163a89dd7ca</id>
<content type='text'>
And other message logging neatening.

Other miscellanea:

o coalesce formats
o realign arguments
o standardize a couple of macros
o use __func__ instead of embedding the function name

Signed-off-by: Joe Perches &lt;joe@perches.com&gt;
Signed-off-by: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
And other message logging neatening.

Other miscellanea:

o coalesce formats
o realign arguments
o standardize a couple of macros
o use __func__ instead of embedding the function name

Signed-off-by: Joe Perches &lt;joe@perches.com&gt;
Signed-off-by: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tile: Replace __get_cpu_var uses</title>
<updated>2014-08-26T17:45:54+00:00</updated>
<author>
<name>Christoph Lameter</name>
<email>cl@linux.com</email>
</author>
<published>2014-08-17T17:30:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b4f501916ce2ae80c28017814d71d1bf83679271'/>
<id>b4f501916ce2ae80c28017814d71d1bf83679271</id>
<content type='text'>
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &amp;__get_cpu_var(x).  This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area.  __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

#define __get_cpu_var(var) (*this_cpu_ptr(&amp;(var)))

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset.  Thereby address calculations are avoided and less registers
are used when code is generated.

At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.

The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e.  using a global
register that may be set to the per cpu base.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &amp;__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&amp;y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&amp;x, this_cpu_ptr(&amp;y), sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	__this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	__this_cpu_inc(y)

Acked-by: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
Signed-off-by: Christoph Lameter &lt;cl@linux.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &amp;__get_cpu_var(x).  This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area.  __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

#define __get_cpu_var(var) (*this_cpu_ptr(&amp;(var)))

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset.  Thereby address calculations are avoided and less registers
are used when code is generated.

At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.

The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e.  using a global
register that may be set to the per cpu base.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &amp;__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&amp;y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&amp;x, this_cpu_ptr(&amp;y), sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	__this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	__this_cpu_inc(y)

Acked-by: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
Signed-off-by: Christoph Lameter &lt;cl@linux.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile</title>
<updated>2013-09-06T18:14:33+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-09-06T18:14:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4de9ad9bc08b4953fc03336ad38908496e2f8826'/>
<id>4de9ad9bc08b4953fc03336ad38908496e2f8826</id>
<content type='text'>
Pull Tile arch updates from Chris Metcalf:
 "These changes bring in a bunch of new functionality that has been
  maintained internally at Tilera over the last year, plus other stray
  bits of work that I've taken into the tile tree from other folks.

  The changes include some PCI root complex work, interrupt-driven
  console support, support for performing fast-path unaligned data
  fixups by kernel-based JIT code generation, CONFIG_PREEMPT support,
  vDSO support for gettimeofday(), a serial driver for the tilegx
  on-chip UART, KGDB support, more optimized string routines, support
  for ftrace and kprobes, improved ASLR, and many bug fixes.

  We also remove support for the old TILE64 chip, which is no longer
  buildable"

* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: (85 commits)
  tile: refresh tile defconfig files
  tile: rework &lt;asm/cmpxchg.h&gt;
  tile PCI RC: make default consistent DMA mask 32-bit
  tile: add null check for kzalloc in tile/kernel/setup.c
  tile: make __write_once a synonym for __read_mostly
  tile: remove support for TILE64
  tile: use asm-generic/bitops/builtin-*.h
  tile: eliminate no-op "noatomichash" boot argument
  tile: use standard tile_bundle_bits type in traps.c
  tile: simplify code referencing hypervisor API addresses
  tile: change &lt;asm/system.h&gt; to &lt;asm/switch_to.h&gt; in comments
  tile: mark pcibios_init() as __init
  tile: check for correct compiler earlier in asm-offsets.c
  tile: use standard 'generic-y' model for &lt;asm/hw_irq.h&gt;
  tile: use asm-generic version of &lt;asm/local64.h&gt;
  tile PCI RC: add comment about "PCI hole" problem
  tile: remove DEBUG_EXTRA_FLAGS kernel config option
  tile: add virt_to_kpte() API and clean up and document behavior
  tile: support FRAME_POINTER
  tile: support reporting Tilera hypervisor statistics
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull Tile arch updates from Chris Metcalf:
 "These changes bring in a bunch of new functionality that has been
  maintained internally at Tilera over the last year, plus other stray
  bits of work that I've taken into the tile tree from other folks.

  The changes include some PCI root complex work, interrupt-driven
  console support, support for performing fast-path unaligned data
  fixups by kernel-based JIT code generation, CONFIG_PREEMPT support,
  vDSO support for gettimeofday(), a serial driver for the tilegx
  on-chip UART, KGDB support, more optimized string routines, support
  for ftrace and kprobes, improved ASLR, and many bug fixes.

  We also remove support for the old TILE64 chip, which is no longer
  buildable"

* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: (85 commits)
  tile: refresh tile defconfig files
  tile: rework &lt;asm/cmpxchg.h&gt;
  tile PCI RC: make default consistent DMA mask 32-bit
  tile: add null check for kzalloc in tile/kernel/setup.c
  tile: make __write_once a synonym for __read_mostly
  tile: remove support for TILE64
  tile: use asm-generic/bitops/builtin-*.h
  tile: eliminate no-op "noatomichash" boot argument
  tile: use standard tile_bundle_bits type in traps.c
  tile: simplify code referencing hypervisor API addresses
  tile: change &lt;asm/system.h&gt; to &lt;asm/switch_to.h&gt; in comments
  tile: mark pcibios_init() as __init
  tile: check for correct compiler earlier in asm-offsets.c
  tile: use standard 'generic-y' model for &lt;asm/hw_irq.h&gt;
  tile: use asm-generic version of &lt;asm/local64.h&gt;
  tile PCI RC: add comment about "PCI hole" problem
  tile: remove DEBUG_EXTRA_FLAGS kernel config option
  tile: add virt_to_kpte() API and clean up and document behavior
  tile: support FRAME_POINTER
  tile: support reporting Tilera hypervisor statistics
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>tile: support CONFIG_PREEMPT</title>
<updated>2013-08-13T20:26:01+00:00</updated>
<author>
<name>Chris Metcalf</name>
<email>cmetcalf@tilera.com</email>
</author>
<published>2013-08-07T15:36:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bc1a298f4e04833db4c430df59b90039f0170515'/>
<id>bc1a298f4e04833db4c430df59b90039f0170515</id>
<content type='text'>
This change adds support for CONFIG_PREEMPT (full kernel preemption).
In addition to the core support, this change includes a number
of places where we fix up uses of smp_processor_id() and per-cpu
variables.  I also eliminate the PAGE_HOME_HERE and PAGE_HOME_UNKNOWN
values for page homing, as it turns out they weren't being used.

Signed-off-by: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This change adds support for CONFIG_PREEMPT (full kernel preemption).
In addition to the core support, this change includes a number
of places where we fix up uses of smp_processor_id() and per-cpu
variables.  I also eliminate the PAGE_HOME_HERE and PAGE_HOME_UNKNOWN
values for page homing, as it turns out they weren't being used.

Signed-off-by: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tile: delete __cpuinit usage from all tile files</title>
<updated>2013-07-14T23:36:54+00:00</updated>
<author>
<name>Paul Gortmaker</name>
<email>paul.gortmaker@windriver.com</email>
</author>
<published>2013-06-18T21:28:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=18f894c145e8515c26da09dd95e06d6b1158775c'/>
<id>18f894c145e8515c26da09dd95e06d6b1158775c</id>
<content type='text'>
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit  -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings.  In any case, they are temporary and harmless.

This removes all the arch/tile uses of the __cpuinit macros from
all C files.  Currently tile does not have any __CPUINIT used in
assembly files.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit  -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings.  In any case, they are temporary and harmless.

This removes all the arch/tile uses of the __cpuinit macros from
all C files.  Currently tile does not have any __CPUINIT used in
assembly files.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tile: Use generic idle loop</title>
<updated>2013-04-08T15:39:28+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2013-03-21T21:50:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0dc8153cfebac68c9523b8852b14f10b31209f08'/>
<id>0dc8153cfebac68c9523b8852b14f10b31209f08</id>
<content type='text'>
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Cc: Paul McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Reviewed-by: Cc: Srivatsa S. Bhat &lt;srivatsa.bhat@linux.vnet.ibm.com&gt;
Cc: Magnus Damm &lt;magnus.damm@gmail.com&gt;
Acked-by: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
Link: http://lkml.kernel.org/r/20130321215235.348460344@linutronix.de
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Cc: Paul McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Reviewed-by: Cc: Srivatsa S. Bhat &lt;srivatsa.bhat@linux.vnet.ibm.com&gt;
Cc: Magnus Damm &lt;magnus.damm@gmail.com&gt;
Acked-by: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
Link: http://lkml.kernel.org/r/20130321215235.348460344@linutronix.de
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
</pre>
</div>
</content>
</entry>
</feed>
