[tip:perf/core] perf tools: Use 64-bit shifts with (TSC) time conversion

From: tip-bot for Adrian Hunter
Date: Tue Mar 08 2016 - 05:32:39 EST


Commit-ID: a23f96ee4d51ebd50b83ce0dbb5d04898fb8e3cb
Gitweb: http://git.kernel.org/tip/a23f96ee4d51ebd50b83ce0dbb5d04898fb8e3cb
Author: Adrian Hunter <adrian.hunter@xxxxxxxxx>
AuthorDate: Mon, 7 Mar 2016 16:44:42 -0300
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 8 Mar 2016 10:11:18 +0100

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@xxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1457005856-6143-9-git-send-email-adrian.hunter@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
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 7945462..72193f1 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 4d4210d..1b74164 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);
}