ARCv2: perf: optimize given that num counters <= 32
authorVineet Gupta <vgupta@synopsys.com>
Thu, 8 Oct 2015 16:47:48 +0000 (22:17 +0530)
committerVineet Gupta <vgupta@synopsys.com>
Tue, 21 Nov 2017 23:20:55 +0000 (15:20 -0800)
commit5b9027d6d044d4917992119d184ab0bb616489cc
tree80b05c4295140b9d1828c1fb0475c3d5bd04f214
parent4d431290402c8d867af7ba45ee75407d68748c4a
ARCv2: perf: optimize given that num counters <= 32

use ffz primitive which maps to ARCv2 instruction, vs. non atomic
__test_and_set_bit

It is unlikely if we will even have more than 32 counters, but still add
a BUILD_BUG to catch that

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
arch/arc/kernel/perf_event.c