Commit a23f96ee authored Mar 07, 2016 by Adrian Hunter Committed by Ingo Molnar Mar 08, 2016

perf tools: Use 64-bit shifts with (TSC) time conversion



Commit b9511cd7 ("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@intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1457005856-6143-9-git-send-email-adrian.hunter@intel.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 4a018cc4

tools/perf/arch/x86/tests/rdpmc.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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);

tools/perf/util/tsc.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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);
		}

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