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authorGeert Uytterhoeven <geert+renesas@glider.be>2023-03-15 15:28:17 +0100
committerAndrew Morton <akpm@linux-foundation.org>2023-03-24 01:18:35 +0100
commit13684e966d46283e0e89b6a4941596dc52b18bf3 (patch)
tree7ffbe1f8f6278b4d7b7cae40c62b3657bb604c65 /lib/dhry_run.c
parentmailmap: add entry for Enric Balletbo i Serra (diff)
downloadlinux-13684e966d46283e0e89b6a4941596dc52b18bf3.tar.xz
linux-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 '')
-rw-r--r--lib/dhry_run.c6
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