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| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2023-03-15 15:28:17 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-03-23 17:18:35 -0700 |
| commit | 13684e966d46283e0e89b6a4941596dc52b18bf3 (patch) | |
| tree | 7ffbe1f8f6278b4d7b7cae40c62b3657bb604c65 /lib | |
| parent | d2e44a50ecebb72257e5deb7ce8d227d7e3f53b9 (diff) | |
| download | linux-stable-13684e966d46283e0e89b6a4941596dc52b18bf3.tar.gz linux-stable-13684e966d46283e0e89b6a4941596dc52b18bf3.tar.bz2 linux-stable-13684e966d46283e0e89b6a4941596dc52b18bf3.zip | |
lib: dhry: fix unstable smp_processor_id(_) usage
When running the in-kernel Dhrystone benchmark with
CONFIG_DEBUG_PREEMPT=y:
BUG: using smp_processor_id() in preemptible [00000000] code: bash/938
Fix this by not using smp_processor_id() directly, but instead wrapping
the whole benchmark inside a get_cpu()/put_cpu() pair. This makes sure
the whole benchmark is run on the same CPU core, and the reported values
are consistent.
Link: https://lkml.kernel.org/r/b0d29932bb24ad82cea7f821e295c898e9657be0.1678890070.git.geert+renesas@glider.be
Fixes: d5528cc16893f1f6 ("lib: add Dhrystone benchmark test")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reported-by: Tobias Klausmann <klausman@schwarzvogel.de>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217179
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/dhry_run.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/lib/dhry_run.c b/lib/dhry_run.c index f9d33efa6d09..f15ac666e9d3 100644 --- a/lib/dhry_run.c +++ b/lib/dhry_run.c @@ -31,6 +31,7 @@ MODULE_PARM_DESC(iterations, static void dhry_benchmark(void) { + unsigned int cpu = get_cpu(); int i, n; if (iterations > 0) { @@ -45,9 +46,10 @@ static void dhry_benchmark(void) } report: + put_cpu(); if (n >= 0) - pr_info("CPU%u: Dhrystones per Second: %d (%d DMIPS)\n", - smp_processor_id(), n, n / DHRY_VAX); + pr_info("CPU%u: Dhrystones per Second: %d (%d DMIPS)\n", cpu, + n, n / DHRY_VAX); else if (n == -EAGAIN) pr_err("Please increase the number of iterations\n"); else |