Messages in this thread Patch in this message | | | From | Martin Kepplinger <> | Subject | [PATCH 5/5] arch: x86: use sign_extend64() for sign extension | Date | Fri, 16 Oct 2015 11:07:07 +0200 |
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Signed-off-by: Martin Kepplinger <martin.kepplinger@theobroma-systems.com> --- arch/x86/kernel/cpu/perf_event_msr.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event_msr.c b/arch/x86/kernel/cpu/perf_event_msr.c index f32ac13..ec863b9 100644 --- a/arch/x86/kernel/cpu/perf_event_msr.c +++ b/arch/x86/kernel/cpu/perf_event_msr.c @@ -163,10 +163,9 @@ again: goto again; delta = now - prev; - if (unlikely(event->hw.event_base == MSR_SMI_COUNT)) { - delta <<= 32; - delta >>= 32; /* sign extend */ - } + if (unlikely(event->hw.event_base == MSR_SMI_COUNT)) + delta = sign_extend64(delta, 31); + local64_add(now - prev, &event->count); } -- 2.1.4
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