linux-kernel - [PATCH 8/8] perf tools: Use 64-bit shifts with (TSC) time conversion

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Date:	Thu,  3 Mar 2016 13:50:56 +0200
From:	Adrian Hunter <adrian.hunter@...el.com>
To:	Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:	Jiri Olsa <jolsa@...hat.com>, linux-kernel@...r.kernel.org,
	Stephane Eranian <eranian@...gle.com>
Subject: [PATCH 8/8] perf tools: Use 64-bit shifts with (TSC) time conversion

Commit b9511cd761fa ("perf/x86: Fix time_shift in perf_event_mmap_page")
altered the time conversion algorithms documented in the perf_event.h
header file, to use 64-bit shifts.  That was done to make the code more
future-proof (i.e. some time in the future a 32-bit shift could be
allowed).  Reflect those changes in perf tools.

Signed-off-by: Adrian Hunter <adrian.hunter@...el.com>
---
 tools/perf/arch/x86/tests/rdpmc.c | 2 +-
 tools/perf/util/tsc.c             | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/arch/x86/tests/rdpmc.c b/tools/perf/arch/x86/tests/rdpmc.c
index 7945462851a4..72193f19d6d7 100644
--- a/tools/perf/arch/x86/tests/rdpmc.c
+++ b/tools/perf/arch/x86/tests/rdpmc.c
@@ -59,7 +59,7 @@ static u64 mmap_read_self(void *addr)
 		u64 quot, rem;
 
 		quot = (cyc >> time_shift);
-		rem = cyc & ((1 << time_shift) - 1);
+		rem = cyc & (((u64)1 << time_shift) - 1);
 		delta = time_offset + quot * time_mult +
 			((rem * time_mult) >> time_shift);
 
diff --git a/tools/perf/util/tsc.c b/tools/perf/util/tsc.c
index 4d4210d4e13d..1b741646eed0 100644
--- a/tools/perf/util/tsc.c
+++ b/tools/perf/util/tsc.c
@@ -19,7 +19,7 @@ u64 tsc_to_perf_time(u64 cyc, struct perf_tsc_conversion *tc)
 	u64 quot, rem;
 
 	quot = cyc >> tc->time_shift;
-	rem  = cyc & ((1 << tc->time_shift) - 1);
+	rem  = cyc & (((u64)1 << tc->time_shift) - 1);
 	return tc->time_zero + quot * tc->time_mult +
 	       ((rem * tc->time_mult) >> tc->time_shift);
 }
-- 
1.9.1