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authorDouglas Anderson <dianders@chromium.org>2023-08-04 07:00:43 -0700
committerAndrew Morton <akpm@linux-foundation.org>2023-08-18 10:19:00 -0700
commit1f38c86bb29f4548b8df01b47a313518e6ed2dfe (patch)
tree204a1574c10f5cb6ac23c6ae8a984421b3094050 /kernel/watchdog.c
parent8d539b84f1e3478436f978ceaf55a0b6cab497b5 (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>
Diffstat (limited to 'kernel/watchdog.c')
-rw-r--r--kernel/watchdog.c9
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");