diff options
| author | Douglas Anderson <dianders@chromium.org> | 2023-08-04 07:00:43 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-08-18 10:19:00 -0700 |
| commit | 1f38c86bb29f4548b8df01b47a313518e6ed2dfe (patch) | |
| tree | 204a1574c10f5cb6ac23c6ae8a984421b3094050 | |
| parent | 8d539b84f1e3478436f978ceaf55a0b6cab497b5 (diff) | |
watchdog/hardlockup: avoid large stack frames in watchdog_hardlockup_check()
After commit 77c12fc95980 ("watchdog/hardlockup: add a "cpu" param to
watchdog_hardlockup_check()") we started storing a `struct cpumask` on the
stack in watchdog_hardlockup_check(). On systems with CONFIG_NR_CPUS set
to 8192 this takes up 1K on the stack. That triggers warnings with
`CONFIG_FRAME_WARN` set to 1024.
We'll use the new trigger_allbutcpu_cpu_backtrace() to avoid needing to
use a CPU mask at all.
Link: https://lkml.kernel.org/r/20230804065935.v4.2.I501ab68cb926ee33a7c87e063d207abf09b9943c@changeid
Fixes: 77c12fc95980 ("watchdog/hardlockup: add a "cpu" param to watchdog_hardlockup_check()")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202307310955.pLZDhpnl-lkp@intel.com
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | kernel/watchdog.c | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 085d7a78f62f..d145305d95fe 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -151,9 +151,6 @@ void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs) */ if (is_hardlockup(cpu)) { unsigned int this_cpu = smp_processor_id(); - struct cpumask backtrace_mask; - - cpumask_copy(&backtrace_mask, cpu_online_mask); /* Only print hardlockups once. */ if (per_cpu(watchdog_hardlockup_warned, cpu)) @@ -167,10 +164,8 @@ void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs) show_regs(regs); else dump_stack(); - cpumask_clear_cpu(cpu, &backtrace_mask); } else { - if (trigger_single_cpu_backtrace(cpu)) - cpumask_clear_cpu(cpu, &backtrace_mask); + trigger_single_cpu_backtrace(cpu); } /* @@ -179,7 +174,7 @@ void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs) */ if (sysctl_hardlockup_all_cpu_backtrace && !test_and_set_bit(0, &watchdog_hardlockup_all_cpu_dumped)) - trigger_cpumask_backtrace(&backtrace_mask); + trigger_allbutcpu_cpu_backtrace(cpu); if (hardlockup_panic) nmi_panic(regs, "Hard LOCKUP"); |