watchdog/hardlockup: add comments to touch_nmi_watchdog()

In preparation for the buddy hardlockup detector, add comments to
touch_nmi_watchdog() to make it obvious that it touches the configured
hardlockup detector regardless of whether it's backed by an NMI.  Also
note that arch_touch_nmi_watchdog() may not be architecture-specific.

Ideally, we'd like to rename these functions but that is a fairly
disruptive change touching a lot of drivers.  After discussion [1] the
plan is to defer this until a good time.

[1] https://lore.kernel.org/r/ZFy0TX1tfhlH8gxj@alley

[akpm@linux-foundation.org: comment changes, per Petr]
  Link: https://lkml.kernel.org/r/ZGyONWPXpE1DcxA5@alley
Link: https://lkml.kernel.org/r/20230519101840.v5.6.I4e47cbfa1bb2ebbcdb5ca16817aa2887f15dc82c@changeid
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Colin Cross <ccross@android.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: Tzung-Bi Shih <tzungbi@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Douglas Anderson 2023-05-19 10:18:30 -07:00 committed by Andrew Morton
parent 1fafaa7745
commit 8b5c59a92b

View file

@ -125,15 +125,30 @@ void watchdog_nmi_disable(unsigned int cpu);
void lockup_detector_reconfigure(void);
/**
* touch_nmi_watchdog - restart NMI watchdog timeout.
* touch_nmi_watchdog - manually reset the hardlockup watchdog timeout.
*
* If the architecture supports the NMI watchdog, touch_nmi_watchdog()
* may be used to reset the timeout - for code which intentionally
* disables interrupts for a long time. This call is stateless.
* If we support detecting hardlockups, touch_nmi_watchdog() may be
* used to pet the watchdog (reset the timeout) - for code which
* intentionally disables interrupts for a long time. This call is stateless.
*
* Though this function has "nmi" in the name, the hardlockup watchdog might
* not be backed by NMIs. This function will likely be renamed to
* touch_hardlockup_watchdog() in the future.
*/
static inline void touch_nmi_watchdog(void)
{
/*
* Pass on to the hardlockup detector selected via CONFIG_. Note that
* the hardlockup detector may not be arch-specific nor using NMIs
* and the arch_touch_nmi_watchdog() function will likely be renamed
* in the future.
*/
arch_touch_nmi_watchdog();
/*
* Touching the hardlock detector implicitly resets the
* softlockup detector too
*/
touch_softlockup_watchdog();
}