[PATCH] Revert "perf machine: Fix paranoid check in machine__set_kernel_mmap()"

From: Kim Phillips
Date: Wed Apr 11 2018 - 19:08:03 EST


perf test 1 is failing on an arm64 box (that has a kernel module
loaded fwiw). Running bisect resulted in commit 1d12cec6ce99 "perf
machine: Fix paranoid check in machine__set_kernel_mmap()" being the
first bad commit. Reverting it fixes symbol resolution:

# ./perf.bad record true; ./perf.bad --no-pager report --stdio --quiet
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.001 MB perf.data (10 samples) ]
64.34% true [unknown] [k] 0xffff20000809ffb8
32.12% true [unknown] [k] 0xffff20000869f400
3.24% true [unknown] [k] 0xffff20000868d924
0.28% perf.ba [unknown] [k] 0xffff200008598b34
0.03% perf.ba [unknown] [k] 0xffff200008598a94

# ./perf.good record true; ./perf.good --no-pager report --stdio --quiet
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.001 MB perf.data (9 samples) ]
91.71% true [kernel.kallsyms] [k] restore_nameidata
7.60% true [kernel.kallsyms] [k] perf_iterate_ctx.constprop.38
0.69% perf.go [kernel.kallsyms] [k] perf_event_exec

Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: <kernel-team@xxxxxxx>
Fixes: 1d12cec6ce99 ("perf machine: Fix paranoid check in machine__set_kernel_mmap()")
Signed-off-by: Kim Phillips <kim.phillips@xxxxxxx>
---
It's not clear to me what the specific intent of the original commit
was, thus the revert.

tools/perf/util/machine.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 2eca8478e24f..089399139778 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1224,7 +1224,7 @@ static void machine__set_kernel_mmap(struct machine *machine,
* Be a bit paranoid here, some perf.data file came with
* a zero sized synthesized MMAP event for the kernel.
*/
- if (start == 0 && end == 0)
+ if (machine->vmlinux_maps[i]->end == 0)
machine->vmlinux_maps[i]->end = ~0ULL;
}
}
--
2.17.0