perf/x86/intel: Disable userspace RDPMC usage for large PEBS

Userspace RDPMC cannot possibly work for large PEBS, which was introduced in:

  b8241d20699e ("perf/x86/intel: Implement batched PEBS interrupt handling (large PEBS interrupt threshold)")

When the PEBS interrupt threshold is larger than one, there is no way
to get exact auto-reload times and value for userspace RDPMC.  Disable
the userspace RDPMC usage when large PEBS is enabled.

The only exception is when the PEBS interrupt threshold is 1, in which
case user-space RDPMC works well even with auto-reload events.

Signed-off-by: Kan Liang <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vince Weaver <[email protected]>
Cc: [email protected]
Fixes: b8241d20699e ("perf/x86/intel: Implement batched PEBS interrupt handling (large PEBS interrupt threshold)")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
(cherry picked from commit 1af22eba248efe2de25658041a80a3d40fb3e92e)

0 files changed, 0 insertions, 0 deletions