git: 112e30301846 - stable/13 - pmcstat: set initial counter value to zero

[Mitchell Horne]

The branch stable/13 has been updated by mhorne:

URL: https://cgit.FreeBSD.org/src/commit/?id=112e30301846d8fede4679a3f95e18820d721bbd

commit 112e30301846d8fede4679a3f95e18820d721bbd
Author:     Mitchell Horne <mhorne at FreeBSD.org>
AuthorDate: 2021-04-21 20:28:12 +0000
Commit:     Mitchell Horne <mhorne at FreeBSD.org>
CommitDate: 2021-04-29 13:19:20 +0000

    pmcstat: set initial counter value to zero
    
    For an infrequent event, pmcstat may report (u_long)-1 for CPUs where
    the counter was never incremented. Just set this to zero, instead.
    
    ev->ev_count is passed as the 'count' argument to pmc_allocate(3), but
    this wasn't always the case.
    
    Reviewed by:    gnn
    MFC after:      1 week
    Sponsored by:   The FreeBSD Foundation
    Differential Revision:  https://reviews.freebsd.org/D29887
    
    (cherry picked from commit edcf9e59c356525632dd2546d72916aeca609a2b)
---
 usr.sbin/pmcstat/pmcstat.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/usr.sbin/pmcstat/pmcstat.c b/usr.sbin/pmcstat/pmcstat.c
index 688a98843652..b7f6c5e0f63e 100644
--- a/usr.sbin/pmcstat/pmcstat.c
+++ b/usr.sbin/pmcstat/pmcstat.c
@@ -675,7 +675,7 @@ main(int argc, char **argv)
 			if (option == 'S' || option == 'P')
 				ev->ev_count = current_sampling_count ? current_sampling_count : pmc_pmu_sample_rate_get(ev->ev_spec);
 			else
-				ev->ev_count = -1;
+				ev->ev_count = 0;
 
 			if (option == 'S' || option == 's')
 				ev->ev_cpu = CPU_FFS(&cpumask) - 1;