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 Signed-off-by: Douglas Anderson <diand...@chromium.org> --- Changes in v5: - No longer rename touch_nmi_watchdog(), just add comments. Changes in v4: - ("Rename touch_nmi_watchdog() to ...") new for v4. include/linux/nmi.h | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) diff --git a/include/linux/nmi.h b/include/linux/nmi.h index 454fe99c4874..fafab128f37e 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -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 pet the hardlockup watchdog. * - * 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 implcitily pets the + * softlockup detector too + */ touch_softlockup_watchdog(); } -- 2.40.1.698.g37aff9b760-goog
