Instead of using per_cpu(..., raw_smp_processor_id()), use
__get_cpu_var(...).
Signed-off-by: NAvi Kivity <avi@redhat.com>
LKML-Reference: <1259578491-4589-1-git-send-email-avi@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Today's linux-next build (x86_64 allmodconfig) failed like this:

  kernel/user-return-notifier.c: In function
  'fire_user_return_notifiers': kernel/user-return-notifier.c:45:
  error: expected expression before ')' token

Introduced by commit 7c68af6e
("core, x86: Add user return notifiers") from the tip and kvm trees
but revealed by commit e0fdb0e0
("percpu: add __percpu for sparse") from the percpu tree.

Before that percpu tree commit, "put_cpu_var()" would compile
without error (even though it really needs a parameter).
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Cc: Avi Kivity <avi@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
LKML-Reference: <20091102161722.eea4358d.sfr@canb.auug.org.au>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Add a general per-cpu notifier that is called whenever the kernel is
about to return to userspace.  The notifier uses a thread_info flag
and existing checks, so there is no impact on user return or context
switch fast paths.

This will be used initially to speed up KVM task switching by lazily
updating MSRs.
Signed-off-by: NAvi Kivity <avi@redhat.com>
LKML-Reference: <1253342422-13811-1-git-send-email-avi@redhat.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>