| commit | 8325a284b1fc1efff248b113d8e8a2626955d5b7 | [log] [tgz] |
|---|---|---|
| author | Ingo Molnar <[email protected]> | Wed Feb 13 06:57:02 2019 |
| committer | chrome-bot <[email protected]> | Wed Feb 20 22:45:11 2019 |
| tree | bc9ee1242aa43a503b6228f0bc2e3fa6003c0792 | |
| parent | 720e311cc8ddca358f65fe1e564ae91ce0f7f036 [diff] |
UPSTREAM: perf/core: Fix impossible ring-buffer sizes warning
The following commit:
9dff0aa95a32 ("perf/core: Don't WARN() for impossible ring-buffer sizes")
results in perf recording failures with larger mmap areas:
root@skl:/tmp# perf record -g -a
failed to mmap with 12 (Cannot allocate memory)
The root cause is that the following condition is buggy:
if (order_base_2(size) >= MAX_ORDER)
goto fail;
The problem is that @size is in bytes and MAX_ORDER is in pages,
so the right test is:
if (order_base_2(size) >= PAGE_SHIFT+MAX_ORDER)
goto fail;
Fix it.
Reported-by: "Jin, Yao" <[email protected]>
Bisected-by: Borislav Petkov <[email protected]>
Analyzed-by: Peter Zijlstra <[email protected]>
Cc: Julien Thierry <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: <[email protected]>
Fixes: 9dff0aa95a32 ("perf/core: Don't WARN() for impossible ring-buffer sizes")
Signed-off-by: Ingo Molnar <[email protected]>
(cherry picked from commit 528871b456026e6127d95b1b2bd8e3a003dc1614)
BUG=b:124795843
TEST=perf record -g -a
Change-Id: I418f2b70c3de76d0c59e7f278107eba4b5d80ba2
Signed-off-by: Guenter Roeck <[email protected]>
Reviewed-on: https://chromium-review.googlesource.com/1478048
Reviewed-by: Sean Paul <[email protected]>
Reviewed-by: Sonny Rao <[email protected]>
Reviewed-by: Yu Zhao <[email protected]>
Reviewed-by: Alexey Alexandrov <[email protected]>