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authorPaul E. McKenney <paulmck@kernel.org>2019-12-05 10:49:11 -0800
committerPaul E. McKenney <paulmck@kernel.org>2020-02-20 16:03:30 -0800
commita59ee765a6890e7f4281070008a2654337458311 (patch)
treeec2bbda358f8fd026e4986d8bc9cab28e89dbda4
parent435508095ab5b6870e8140948983920ce4684e9b (diff)
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torture: Forgive -EBUSY from boottime CPU-hotplug operations
During boot, CPU hotplug is often disabled, for example by PCI probing. On large systems that take substantial time to boot, this can result in spurious RCU_HOTPLUG errors. This commit therefore forgives any boottime -EBUSY CPU-hotplug failures by adjusting counters to pretend that the corresponding attempt never happened. A non-splat record of the failed attempt is emitted to the console with the added string "(-EBUSY forgiven during boot)". Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
-rw-r--r--kernel/torture.c22
1 files changed, 18 insertions, 4 deletions
diff --git a/kernel/torture.c b/kernel/torture.c
index 7c13f5558b71..e377b5b17de8 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -84,6 +84,7 @@ bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes,
{
unsigned long delta;
int ret;
+ char *s;
unsigned long starttime;
if (!cpu_online(cpu) || !cpu_is_hotpluggable(cpu))
@@ -99,10 +100,16 @@ bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes,
(*n_offl_attempts)++;
ret = cpu_down(cpu);
if (ret) {
+ s = "";
+ if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) {
+ // PCI probe frequently disables hotplug during boot.
+ (*n_offl_attempts)--;
+ s = " (-EBUSY forgiven during boot)";
+ }
if (verbose)
pr_alert("%s" TORTURE_FLAG
- "torture_onoff task: offline %d failed: errno %d\n",
- torture_type, cpu, ret);
+ "torture_onoff task: offline %d failed%s: errno %d\n",
+ torture_type, cpu, s, ret);
} else {
if (verbose > 1)
pr_alert("%s" TORTURE_FLAG
@@ -137,6 +144,7 @@ bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes,
{
unsigned long delta;
int ret;
+ char *s;
unsigned long starttime;
if (cpu_online(cpu) || !cpu_is_hotpluggable(cpu))
@@ -150,10 +158,16 @@ bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes,
(*n_onl_attempts)++;
ret = cpu_up(cpu);
if (ret) {
+ s = "";
+ if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) {
+ // PCI probe frequently disables hotplug during boot.
+ (*n_onl_attempts)--;
+ s = " (-EBUSY forgiven during boot)";
+ }
if (verbose)
pr_alert("%s" TORTURE_FLAG
- "torture_onoff task: online %d failed: errno %d\n",
- torture_type, cpu, ret);
+ "torture_onoff task: online %d failed%s: errno %d\n",
+ torture_type, cpu, s, ret);
} else {
if (verbose > 1)
pr_alert("%s" TORTURE_FLAG