watchdog/hardlockup: avoid large stack frames in watchdog_hardlockup_check()
authorDouglas Anderson <dianders@chromium.org>
Fri, 4 Aug 2023 14:00:43 +0000 (07:00 -0700)
committerAndrew Morton <akpm@linux-foundation.org>
Fri, 18 Aug 2023 17:19:00 +0000 (10:19 -0700)
commit1f38c86bb29f4548b8df01b47a313518e6ed2dfe
tree204a1574c10f5cb6ac23c6ae8a984421b3094050
parent8d539b84f1e3478436f978ceaf55a0b6cab497b5
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>
kernel/watchdog.c