On Fri 2023-06-16 17:06:12, Petr Mladek wrote: > Hi, > > this patchset is supposed to replace the last patch in the patchset cleaning > up after introducing the buddy detector, see > https://lore.kernel.org/r/20230526184139.10.I821fe7609e57608913fe05abd8f35b343e7a9aae@changeid > > Changes against v1: > > + Better explained the C-like ordering in the 1st patch. > > + Squashed patches for splitting and renaming HAVE_NMI_WATCHDOG, > updated commit message with the history and more facts. > > + Updated comments about the sparc64 variant. It is not handled together > with the softlockup detector. In fact, it is always build. And it even > used to be always enabled until the commit 7a5c8b57cec93196b ("sparc: > implement watchdog_nmi_enable and watchdog_nmi_disable") added in > v4.10-rc1. > > I realized this when updating the comment for the 4th patch. My original > statement in v1 patchset was based on code reading. I looked at it from > a bad side. > > + Removed superfluous "default n" > + Fixed typos. I sometimes find the diff between the two versions useful. Especially, when the patches are not trivial and the last version made only cosmetic changes. This is what I got by comparing "git format-patch" generated patchsets: diff -purN watchdog-buddy-hardlockup-detector-config-cleanup-v1-iter1-reference/0000-cover-letter.patch watchdog-buddy-hardlockup-detector-config-cleanup-v2-iter1/0000-cover-letter.patch --- watchdog-buddy-hardlockup-detector-config-cleanup-v1-iter1-reference/0000-cover-letter.patch 2023-06-16 16:42:07.769941775 +0200 +++ watchdog-buddy-hardlockup-detector-config-cleanup-v2-iter1/0000-cover-letter.patch 2023-06-16 16:39:42.179877676 +0200 @@ -1,9 +1,33 @@ -From 0456ed568d98ba5bba8148e4f60d769e3c5a6c7a Mon Sep 17 00:00:00 2001 +From bcf4dfab5a64ee691eb5154b1361ed59610c9387 Mon Sep 17 00:00:00 2001 From: Petr Mladek <pmladek@xxxxxxxx> -Date: Fri, 16 Jun 2023 16:42:07 +0200 -Subject: [PATCH 0/6] *** SUBJECT HERE *** +Date: Fri, 16 Jun 2023 16:28:13 +0200 +Subject: [PATCH v2 0/6] watchdog/hardlockup: Cleanup configuration of hardlockup detectors -*** BLURB HERE *** +Hi, + +this patchset is supposed to replace the last patch in the patchset cleaning +up after introducing the buddy detector, see +https://lore.kernel.org/r/20230526184139.10.I821fe7609e57608913fe05abd8f35b343e7a9aae@changeid + +Changes against v1: + + + Better explained the C-like ordering in the 1st patch. + + + Squashed patches for splitting and renaming HAVE_NMI_WATCHDOG, + updated commit message with the history and more facts. + + + Updated comments about the sparc64 variant. It is not handled together + with the softlockup detector. In fact, it is always build. And it even + used to be always enabled until the commit 7a5c8b57cec93196b ("sparc: + implement watchdog_nmi_enable and watchdog_nmi_disable") added in + v4.10-rc1. + + I realized this when updating the comment for the 4th patch. My original + statement in v1 patchset was based on code reading. I looked at it from + a bad side. + + + Removed superfluous "default n" + + Fixed typos. Petr Mladek (6): watchdog/hardlockup: Sort hardlockup detector related config values a @@ -19,12 +43,12 @@ Petr Mladek (6): arch/powerpc/Kconfig | 5 +- arch/powerpc/include/asm/nmi.h | 2 - arch/sparc/Kconfig | 2 +- - arch/sparc/Kconfig.debug | 20 ++++++ + arch/sparc/Kconfig.debug | 14 ++++ arch/sparc/include/asm/nmi.h | 1 - include/linux/nmi.h | 14 ++-- kernel/watchdog.c | 2 +- - lib/Kconfig.debug | 115 +++++++++++++++++++-------------- - 9 files changed, 104 insertions(+), 74 deletions(-) + lib/Kconfig.debug | 114 ++++++++++++++++++--------------- + 9 files changed, 97 insertions(+), 74 deletions(-) -- 2.35.3 diff -purN watchdog-buddy-hardlockup-detector-config-cleanup-v1-iter1-reference/0001-watchdog-hardlockup-Sort-hardlockup-detector-related.patch watchdog-buddy-hardlockup-detector-config-cleanup-v2-iter1/0001-watchdog-hardlockup-Sort-hardlockup-detector-related.patch --- watchdog-buddy-hardlockup-detector-config-cleanup-v1-iter1-reference/0001-watchdog-hardlockup-Sort-hardlockup-detector-related.patch 2023-06-16 16:42:07.741941379 +0200 +++ watchdog-buddy-hardlockup-detector-config-cleanup-v2-iter1/0001-watchdog-hardlockup-Sort-hardlockup-detector-related.patch 2023-06-16 16:28:53.594682369 +0200 @@ -1,7 +1,7 @@ -From 9d643e4254b224d22dd1411c51386ab686c052a7 Mon Sep 17 00:00:00 2001 +From bd7019bff3a28fb0bc163308101118adccf699d3 Mon Sep 17 00:00:00 2001 From: Petr Mladek <pmladek@xxxxxxxx> Date: Thu, 1 Jun 2023 15:35:09 +0200 -Subject: [PATCH 1/6] watchdog/hardlockup: Sort hardlockup detector related +Subject: [PATCH v2 1/6] watchdog/hardlockup: Sort hardlockup detector related config values a logical way There are four possible variants of hardlockup detectors: @@ -40,6 +40,14 @@ The logical order is: are temporary variables that are going to be removed in a followup patch. +This is a preparation step for further cleanup. It will change the logic +without shuffling the definitions. + +This change temporary breaks the C-like ordering where the variables are +declared or defined before they are used. It is not really needed for +Kconfig. Also the following patches will rework the logic so that +the ordering will be C-like in the end. + The patch just shuffles the definitions. It should not change the existing behavior. diff -purN watchdog-buddy-hardlockup-detector-config-cleanup-v1-iter1-reference/0002-watchdog-hardlockup-Make-the-config-checks-more-stra.patch watchdog-buddy-hardlockup-detector-config-cleanup-v2-iter1/0002-watchdog-hardlockup-Make-the-config-checks-more-stra.patch --- watchdog-buddy-hardlockup-detector-config-cleanup-v1-iter1-reference/0002-watchdog-hardlockup-Make-the-config-checks-more-stra.patch 2023-06-16 16:42:07.745941436 +0200 +++ watchdog-buddy-hardlockup-detector-config-cleanup-v2-iter1/0002-watchdog-hardlockup-Make-the-config-checks-more-stra.patch 2023-06-16 16:28:53.594682369 +0200 @@ -1,7 +1,7 @@ -From b36400b9adf92a911dc2b9ee8f471cf3066a9f74 Mon Sep 17 00:00:00 2001 +From 91fabffa4aafae0611130d4de0471e847cee67dc Mon Sep 17 00:00:00 2001 From: Petr Mladek <pmladek@xxxxxxxx> Date: Thu, 1 Jun 2023 17:10:11 +0200 -Subject: [PATCH 2/6] watchdog/hardlockup: Make the config checks more +Subject: [PATCH v2 2/6] watchdog/hardlockup: Make the config checks more straightforward There are four possible variants of hardlockup detectors: @@ -55,19 +55,19 @@ Make the logic more straightforward by t Another nice side effect is that HARDLOCKUP_DETECTOR_PREFER_BUDDY value is not preserved when the global switch is disabled. - The user has to make the decision when it is enabled again. + The user has to make the decision again when it gets re-enabled. Signed-off-by: Petr Mladek <pmladek@xxxxxxxx> --- - arch/Kconfig | 22 ++++++++++++----- - lib/Kconfig.debug | 63 ++++++++++++++++++++++++++++------------------- + arch/Kconfig | 23 +++++++++++++----- + lib/Kconfig.debug | 62 +++++++++++++++++++++++++++-------------------- 2 files changed, 53 insertions(+), 32 deletions(-) diff --git a/arch/Kconfig b/arch/Kconfig -index 422f0ffa269e..13c6e596cf9e 100644 +index 422f0ffa269e..77e5af5fda3f 100644 --- a/arch/Kconfig +++ b/arch/Kconfig -@@ -404,17 +404,27 @@ config HAVE_NMI_WATCHDOG +@@ -404,17 +404,28 @@ config HAVE_NMI_WATCHDOG depends on HAVE_NMI bool help @@ -75,13 +75,14 @@ index 422f0ffa269e..13c6e596cf9e 100644 - asm/nmi.h, and defines its own watchdog_hardlockup_probe() and - arch_touch_nmi_watchdog(). + The arch provides its own hardlockup detector implementation instead -+ of the generic perf one. ++ of the generic ones. + + Sparc64 defines this variable without HAVE_HARDLOCKUP_DETECTOR_ARCH. -+ It does _not_ use the command line parameters and sysctl interface -+ used by generic hardlockup detectors. Instead it is enabled/disabled -+ by the top-level watchdog interface that is common for both softlockup -+ and hardlockup detectors. ++ It is the last arch-specific implementation which was developed before ++ adding the common infrastructure for handling hardlockup detectors. ++ It is always built. It does _not_ use the common command line ++ parameters and sysctl interface, except for ++ /proc/sys/kernel/nmi_watchdog. config HAVE_HARDLOCKUP_DETECTOR_ARCH bool @@ -102,7 +103,7 @@ index 422f0ffa269e..13c6e596cf9e 100644 config HAVE_PERF_REGS bool diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug -index 3e91fa33c7a0..d201f5d3876b 100644 +index 3e91fa33c7a0..a0b0c4decb89 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1035,16 +1035,33 @@ config BOOTPARAM_SOFTLOCKUP_PANIC @@ -119,7 +120,7 @@ index 3e91fa33c7a0..d201f5d3876b 100644 -# lockup detector rather than the perf based detector. +# Global switch whether to build a hardlockup detector at all. It is available +# only when the architecture supports at least one implementation. There are -+# two exceptions. The hardlockup detector is newer enabled on: ++# two exceptions. The hardlockup detector is never enabled on: +# +# s390: it reported many false positives there +# @@ -143,7 +144,7 @@ index 3e91fa33c7a0..d201f5d3876b 100644 help Say Y here to enable the kernel to act as a watchdog to detect -@@ -1055,9 +1072,15 @@ config HARDLOCKUP_DETECTOR +@@ -1055,9 +1072,14 @@ config HARDLOCKUP_DETECTOR chance to run. The current stack trace is displayed upon detection and the system will stay locked up. @@ -156,11 +157,10 @@ index 3e91fa33c7a0..d201f5d3876b 100644 + depends on HARDLOCKUP_DETECTOR + depends on HAVE_HARDLOCKUP_DETECTOR_PERF && HAVE_HARDLOCKUP_DETECTOR_BUDDY + depends on !HAVE_NMI_WATCHDOG -+ default n help Say Y here to prefer the buddy hardlockup detector over the perf one. -@@ -1071,39 +1094,27 @@ config HARDLOCKUP_DETECTOR_PREFER_BUDDY +@@ -1071,39 +1093,27 @@ config HARDLOCKUP_DETECTOR_PREFER_BUDDY config HARDLOCKUP_DETECTOR_PERF bool diff -purN watchdog-buddy-hardlockup-detector-config-cleanup-v1-iter1-reference/0003-watchdog-hardlockup-Declare-arch_touch_nmi_watchdog-.patch watchdog-buddy-hardlockup-detector-config-cleanup-v2-iter1/0003-watchdog-hardlockup-Declare-arch_touch_nmi_watchdog-.patch --- watchdog-buddy-hardlockup-detector-config-cleanup-v1-iter1-reference/0003-watchdog-hardlockup-Declare-arch_touch_nmi_watchdog-.patch 2023-06-16 16:42:07.749941492 +0200 +++ watchdog-buddy-hardlockup-detector-config-cleanup-v2-iter1/0003-watchdog-hardlockup-Declare-arch_touch_nmi_watchdog-.patch 2023-06-16 16:28:53.594682369 +0200 @@ -1,16 +1,17 @@ -From b132b032466f5c07bc31bb1c22ed6db32871d725 Mon Sep 17 00:00:00 2001 +From f4b7044dd7847ae8d12535c464ea4bd0568b5456 Mon Sep 17 00:00:00 2001 From: Petr Mladek <pmladek@xxxxxxxx> Date: Fri, 2 Jun 2023 16:38:43 +0200 -Subject: [PATCH 3/6] watchdog/hardlockup: Declare arch_touch_nmi_watchdog() +Subject: [PATCH v2 3/6] watchdog/hardlockup: Declare arch_touch_nmi_watchdog() only in linux/nmi.h arch_touch_nmi_watchdog() needs a different implementation for various hardlockup detector implementations. And it does nothing when -any hardlockup detector is not build at all. +any hardlockup detector is not built at all. -arch_touch_nmi_watchdog() has to be declared in linux/nmi.h. It is done -directly in this header file for the perf and buddy detectors. And it -is done in the included asm/linux.h for arch specific detectors. +arch_touch_nmi_watchdog() is declared via linux/nmi.h. And it must be +defined as an empty function when there is no hardlockup detector. +It is done directly in this header file for the perf and buddy detectors. +And it is done in the included asm/linux.h for arch specific detectors. The reason probably is that the arch specific variants build the code using another conditions. For example, powerpc64/sparc64 builds the code @@ -19,13 +20,14 @@ when CONFIG_PPC_WATCHDOG is enabled. Another reason might be that these architectures define more functions in asm/nmi.h anyway. -However the generic code actually knows the information. The config -variables HAVE_NMI_WATCHDOG and HAVE_HARDLOCKUP_DETECTOR_ARCH are used -to decide whether to build the buddy detector. - -In particular, CONFIG_HARDLOCKUP_DETECTOR is set only when a generic -or arch-specific hardlockup detector is built. The only exception -is sparc64 which ignores the global HARDLOCKUP_DETECTOR switch. +However the generic code actually knows when the function will be +implemented. It happens when some full featured or the sparc64-specific +hardlockup detector is built. + +In particular, CONFIG_HARDLOCKUP_DETECTOR can be enabled only when +a generic or arch-specific full featured hardlockup detector is available. +The only exception is sparc64 which can be built even when the global +HARDLOCKUP_DETECTOR switch is disabled. The information about sparc64 is a bit complicated. The hardlockup detector is built there when CONFIG_HAVE_NMI_WATCHDOG is set and @@ -48,6 +50,7 @@ The motivation is: The change should not change the existing behavior. Signed-off-by: Petr Mladek <pmladek@xxxxxxxx> +Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx> --- arch/powerpc/include/asm/nmi.h | 2 -- arch/sparc/include/asm/nmi.h | 1 - diff -purN watchdog-buddy-hardlockup-detector-config-cleanup-v1-iter1-reference/0004-watchdog-hardlockup-Make-HAVE_NMI_WATCHDOG-sparc64-s.patch watchdog-buddy-hardlockup-detector-config-cleanup-v2-iter1/0004-watchdog-hardlockup-Make-HAVE_NMI_WATCHDOG-sparc64-s.patch --- watchdog-buddy-hardlockup-detector-config-cleanup-v1-iter1-reference/0004-watchdog-hardlockup-Make-HAVE_NMI_WATCHDOG-sparc64-s.patch 2023-06-16 16:42:07.757941606 +0200 +++ watchdog-buddy-hardlockup-detector-config-cleanup-v2-iter1/0004-watchdog-hardlockup-Make-HAVE_NMI_WATCHDOG-sparc64-s.patch 2023-06-16 16:28:53.598682426 +0200 @@ -1,58 +1,95 @@ -From b898a6715dd01a5e3a6a404d70e12dcb2d9d7d0d Mon Sep 17 00:00:00 2001 +From 89632da8754cb2a70a48b357c2d5f099b121b88a Mon Sep 17 00:00:00 2001 From: Petr Mladek <pmladek@xxxxxxxx> -Date: Tue, 6 Jun 2023 17:19:08 +0200 -Subject: [PATCH 4/6] watchdog/hardlockup: Make HAVE_NMI_WATCHDOG +Date: Fri, 16 Jun 2023 15:43:34 +0200 +Subject: [PATCH v2 4/6] watchdog/hardlockup: Make HAVE_NMI_WATCHDOG sparc64-specific -watchdog/hardlockup: Enable HAVE_NMI_WATCHDOG only on sparc64 +There are several hardlockup detector implementations and several Kconfig +values which allow selection and build of the preferred one. -HAVE_NMI_WATCHDOG is always enabled when SPARC64 is enabled. The sparc64 -implementation is special. It does not support the generic hardlockup -related Kconfig values, command line parameters, and sysctl interface. -Instead it is enabled/disabled by the top-level watchdog interface -that is common for both softlockup and hardlockup detectors. - -As a result, sparc64 needs special treating in Kconfig and source -files. The checks are a bit complicated because HAVE_NMI_WATCHDOG is -automatically set when HAVE_HARDLOCKUP_DETECTOR_ARCH is set. -But HAVE_HARDLOCKUP_DETECTOR_ARCH is set when the arch specific -implementation uses the generic hardlockup detector related -Kconfig variables, command line parameters, and sysctl interface. - -The motivation probably was to avoid changes in the code when -the powerpc64-specific watchdog introduced HAVE_HARDLOCKUP_DETECTOR_ARCH. -It probably allowed to re-use some existing checks for HAVE_NMI_WATCHDOG. - -But it actually made things pretty complicated. For example, -the following check was needed in HARDLOCKUP_DETECTOR config variable: - - depends on ((HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_BUDDY) && !HAVE_NMI_WATCHDOG) || HAVE_HARDLOCKUP_DETECTOR_ARCH - -The inverted logic makes things easier: - - + HAVE_NMI_WATCHDOG is used only on sparc64. It is clear when - the sparc64 specific watchdog is used. - - + HAVE_HARDLOCKUP_DETECTOR_ARCH is basically compatible with - the generic watchdogs. As a result, the common code - is marked by ifdef CONFIG_HARDLOCKUP_DETECTOR. - -As a result: - - + Some conditions are easier. - - + Some conditions use HAVE_HARDLOCKUP_DETECTOR_ARCH instead of - HAVE_NMI_WATCHDOG. +CONFIG_HARDLOCKUP_DETECTOR was introduced by the commit 23637d477c1f53acb +("lockup_detector: Introduce CONFIG_HARDLOCKUP_DETECTOR") in v2.6.36. +It was a preparation step for introducing the new generic perf hardlockup +detector. + +The existing arch-specific variants did not support the to-be-created +generic build configurations, sysctl interface, etc. This distinction +was made explicit by the commit 4a7863cc2eb5f98 ("x86, nmi_watchdog: +Remove ARCH_HAS_NMI_WATCHDOG and rely on CONFIG_HARDLOCKUP_DETECTOR") +in v2.6.38. + +CONFIG_HAVE_NMI_WATCHDOG was introduced by the commit d314d74c695f967e105 +("nmi watchdog: do not use cpp symbol in Kconfig") in v3.4-rc1. It replaced +the above mentioned ARCH_HAS_NMI_WATCHDOG. At that time, it was still used +by three architectures, namely blackfin, mn10300, and sparc. + +The support for blackfin and mn10300 architectures has been completely +dropped some time ago. And sparc is the only architecture with the historic +NMI watchdog at the moment. + +And the old sparc implementation is really special. It is always built on +sparc64. It used to be always enabled until the commit 7a5c8b57cec93196b +("sparc: implement watchdog_nmi_enable and watchdog_nmi_disable") added +in v4.10-rc1. + +There are only few locations where the sparc64 NMI watchdog interacts +with the generic hardlockup detectors code: + + + implements arch_touch_nmi_watchdog() which is called from the generic + touch_nmi_watchdog() + + + implements watchdog_hardlockup_enable()/disable() to support + /proc/sys/kernel/nmi_watchdog + + + is always preferred over other generic watchdogs, see + CONFIG_HARDLOCKUP_DETECTOR + + + includes asm/nmi.h into linux/nmi.h because some sparc-specific + functions are needed in sparc-specific code which includes + only linux/nmi.h. + +The situation became more complicated after the commit 05a4a95279311c3 +("kernel/watchdog: split up config options") and commit 2104180a53698df5 +("powerpc/64s: implement arch-specific hardlockup watchdog") in v4.13-rc1. +They introduced HAVE_HARDLOCKUP_DETECTOR_ARCH. It was used for powerpc +specific hardlockup detector. It was compatible with the perf one +regarding the general boot, sysctl, and programming interfaces. + +HAVE_HARDLOCKUP_DETECTOR_ARCH was defined as a superset of +HAVE_NMI_WATCHDOG. It made some sense because all arch-specific +detectors had some common requirements, namely: + + + implemented arch_touch_nmi_watchdog() + + included asm/nmi.h into linux/nmi.h + + defined the default value for /proc/sys/kernel/nmi_watchdog + +But it actually has made things pretty complicated when the generic +buddy hardlockup detector was added. Before the generic perf detector +was newer supported together with an arch-specific one. But the buddy +detector could work on any SMP system. It means that an architecture +could support both the arch-specific and buddy detector. + +As a result, there are few tricky dependencies. For example, +CONFIG_HARDLOCKUP_DETECTOR depends on: + + ((HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_BUDDY) && !HAVE_NMI_WATCHDOG) || HAVE_HARDLOCKUP_DETECTOR_ARCH + +The problem is that the very special sparc implementation is defined as: + + HAVE_NMI_WATCHDOG && !HAVE_HARDLOCKUP_DETECTOR_ARCH + +Another problem is that the meaning of HAVE_NMI_WATCHDOG is far from clear +without reading understanding the history. + +Make the logic less tricky and more self-explanatory by making +HAVE_NMI_WATCHDOG specific for the sparc64 implementation. And rename it to +HAVE_HARDLOCKUP_DETECTOR_SPARC64. Note that HARDLOCKUP_DETECTOR_PREFER_BUDDY, HARDLOCKUP_DETECTOR_PERF, -and HARDLOCKUP_DETECTOR_BUDDY might depend only on +and HARDLOCKUP_DETECTOR_BUDDY may conflict only with HAVE_HARDLOCKUP_DETECTOR_ARCH. They depend on HARDLOCKUP_DETECTOR and it is not longer enabled when HAVE_NMI_WATCHDOG is set. -Note that asm/nmi.h still has to be included for all arch-specific -watchdogs. It declares more functions that are used in another -arch specific code which includes only linux/nmi.h. - Signed-off-by: Petr Mladek <pmladek@xxxxxxxx> watchdog/sparc64: Rename HAVE_NMI_WATCHDOG to HAVE_HARDLOCKUP_WATCHDOG_SPARC64 @@ -74,19 +111,19 @@ from arch/Kconfig to arch/sparc/Kconfig. Signed-off-by: Petr Mladek <pmladek@xxxxxxxx> --- - arch/Kconfig | 17 ----------------- + arch/Kconfig | 18 ------------------ arch/sparc/Kconfig | 2 +- - arch/sparc/Kconfig.debug | 12 ++++++++++++ + arch/sparc/Kconfig.debug | 9 +++++++++ include/linux/nmi.h | 5 ++--- kernel/watchdog.c | 2 +- lib/Kconfig.debug | 15 +++++---------- - 6 files changed, 21 insertions(+), 32 deletions(-) + 6 files changed, 18 insertions(+), 33 deletions(-) diff --git a/arch/Kconfig b/arch/Kconfig -index 13c6e596cf9e..6517e5477459 100644 +index 77e5af5fda3f..6517e5477459 100644 --- a/arch/Kconfig +++ b/arch/Kconfig -@@ -400,22 +400,8 @@ config HAVE_HARDLOCKUP_DETECTOR_PERF +@@ -400,23 +400,8 @@ config HAVE_HARDLOCKUP_DETECTOR_PERF The arch chooses to use the generic perf-NMI-based hardlockup detector. Must define HAVE_PERF_EVENTS_NMI. @@ -95,13 +132,14 @@ index 13c6e596cf9e..6517e5477459 100644 - bool - help - The arch provides its own hardlockup detector implementation instead -- of the generic perf one. +- of the generic ones. - - Sparc64 defines this variable without HAVE_HARDLOCKUP_DETECTOR_ARCH. -- It does _not_ use the command line parameters and sysctl interface -- used by generic hardlockup detectors. Instead it is enabled/disabled -- by the top-level watchdog interface that is common for both softlockup -- and hardlockup detectors. +- It is the last arch-specific implementation which was developed before +- adding the common infrastructure for handling hardlockup detectors. +- It is always built. It does _not_ use the common command line +- parameters and sysctl interface, except for +- /proc/sys/kernel/nmi_watchdog. - config HAVE_HARDLOCKUP_DETECTOR_ARCH bool @@ -109,7 +147,7 @@ index 13c6e596cf9e..6517e5477459 100644 help The arch provides its own hardlockup detector implementation instead of the generic ones. -@@ -423,9 +409,6 @@ config HAVE_HARDLOCKUP_DETECTOR_ARCH +@@ -424,9 +409,6 @@ config HAVE_HARDLOCKUP_DETECTOR_ARCH It uses the same command line parameters, and sysctl interface, as the generic hardlockup detectors. @@ -133,10 +171,10 @@ index 8535e19062f6..7297f69635cb 100644 select HAVE_EBPF_JIT if SPARC64 select HAVE_DEBUG_BUGVERBOSE diff --git a/arch/sparc/Kconfig.debug b/arch/sparc/Kconfig.debug -index 6b2bec1888b3..b6695303b8d4 100644 +index 6b2bec1888b3..4903b6847e43 100644 --- a/arch/sparc/Kconfig.debug +++ b/arch/sparc/Kconfig.debug -@@ -14,3 +14,15 @@ config FRAME_POINTER +@@ -14,3 +14,12 @@ config FRAME_POINTER bool depends on MCOUNT default y @@ -145,13 +183,10 @@ index 6b2bec1888b3..b6695303b8d4 100644 + depends on HAVE_NMI + bool + help -+ Sparc64 provides its own hardlockup detector implementation instead -+ of the generic perf one. -+ -+ It does _not_ use the command line parameters and sysctl interface -+ used by generic hardlockup detectors. Instead it is enabled/disabled -+ by the top-level watchdog interface that is common for both softlockup -+ and hardlockup detectors. ++ Sparc64 hardlockup detector is the last one developed before adding ++ the common infrastructure for handling hardlockup detectors. It is ++ always built. It does _not_ use the common command line parameters ++ and sysctl interface, except for /proc/sys/kernel/nmi_watchdog. diff --git a/include/linux/nmi.h b/include/linux/nmi.h index b9e816bde14a..7ee6c35d1f05 100644 --- a/include/linux/nmi.h @@ -189,7 +224,7 @@ index 437c198933cf..babd2f3c8b72 100644 #else # define WATCHDOG_HARDLOCKUP_DEFAULT 0 diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug -index d201f5d3876b..2d8d8ce7c2d7 100644 +index a0b0c4decb89..e94664339e28 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1050,15 +1050,10 @@ config HAVE_HARDLOCKUP_DETECTOR_BUDDY @@ -216,10 +251,10 @@ index d201f5d3876b..2d8d8ce7c2d7 100644 depends on HAVE_HARDLOCKUP_DETECTOR_PERF && HAVE_HARDLOCKUP_DETECTOR_BUDDY - depends on !HAVE_NMI_WATCHDOG + depends on !HAVE_HARLOCKUP_DETECTOR_ARCH - default n help Say Y here to prefer the buddy hardlockup detector over the perf one. -@@ -1096,7 +1091,7 @@ config HARDLOCKUP_DETECTOR_PERF + +@@ -1095,7 +1090,7 @@ config HARDLOCKUP_DETECTOR_PERF bool depends on HARDLOCKUP_DETECTOR depends on HAVE_HARDLOCKUP_DETECTOR_PERF && !HARDLOCKUP_DETECTOR_PREFER_BUDDY @@ -228,7 +263,7 @@ index d201f5d3876b..2d8d8ce7c2d7 100644 select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER config HARDLOCKUP_DETECTOR_BUDDY -@@ -1104,7 +1099,7 @@ config HARDLOCKUP_DETECTOR_BUDDY +@@ -1103,7 +1098,7 @@ config HARDLOCKUP_DETECTOR_BUDDY depends on HARDLOCKUP_DETECTOR depends on HAVE_HARDLOCKUP_DETECTOR_BUDDY depends on !HAVE_HARDLOCKUP_DETECTOR_PERF || HARDLOCKUP_DETECTOR_PREFER_BUDDY diff -purN watchdog-buddy-hardlockup-detector-config-cleanup-v1-iter1-reference/0005-watchdog-sparc64-Define-HARDLOCKUP_DETECTOR_SPARC64.patch watchdog-buddy-hardlockup-detector-config-cleanup-v2-iter1/0005-watchdog-sparc64-Define-HARDLOCKUP_DETECTOR_SPARC64.patch --- watchdog-buddy-hardlockup-detector-config-cleanup-v1-iter1-reference/0005-watchdog-sparc64-Define-HARDLOCKUP_DETECTOR_SPARC64.patch 2023-06-16 16:42:07.761941662 +0200 +++ watchdog-buddy-hardlockup-detector-config-cleanup-v2-iter1/0005-watchdog-sparc64-Define-HARDLOCKUP_DETECTOR_SPARC64.patch 2023-06-16 16:28:53.598682426 +0200 @@ -1,7 +1,7 @@ -From 39b335cbe5fff566d41a35b1211f92a5d1a56575 Mon Sep 17 00:00:00 2001 +From 1426aca29d60fcaa06c8ca125f236beca28f997a Mon Sep 17 00:00:00 2001 From: Petr Mladek <pmladek@xxxxxxxx> -Date: Wed, 7 Jun 2023 14:59:58 +0200 -Subject: [PATCH 5/6] watchdog/sparc64: Define HARDLOCKUP_DETECTOR_SPARC64 +Date: Fri, 16 Jun 2023 15:45:49 +0200 +Subject: [PATCH v2 5/6] watchdog/sparc64: Define HARDLOCKUP_DETECTOR_SPARC64 The HAVE_ prefix means that the code could be enabled. Add another variable for HAVE_HARDLOCKUP_DETECTOR_SPARC64 without this prefix. @@ -24,18 +24,19 @@ CONFIG_HAVE_HARDLOCKUP_DETECTOR_SPARC64= CONFIG_HARDLOCKUP_DETECTOR_SPARC64=y Signed-off-by: Petr Mladek <pmladek@xxxxxxxx> +Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx> --- - arch/sparc/Kconfig.debug | 10 +++++++++- - include/linux/nmi.h | 4 ++-- - kernel/watchdog.c | 2 +- - lib/Kconfig.debug | 2 +- - 4 files changed, 13 insertions(+), 5 deletions(-) + arch/sparc/Kconfig.debug | 7 ++++++- + include/linux/nmi.h | 4 ++-- + kernel/watchdog.c | 2 +- + lib/Kconfig.debug | 2 +- + 4 files changed, 10 insertions(+), 5 deletions(-) diff --git a/arch/sparc/Kconfig.debug b/arch/sparc/Kconfig.debug -index b6695303b8d4..0bb95b0aacf4 100644 +index 4903b6847e43..37e003665de6 100644 --- a/arch/sparc/Kconfig.debug +++ b/arch/sparc/Kconfig.debug -@@ -16,8 +16,9 @@ config FRAME_POINTER +@@ -16,10 +16,15 @@ config FRAME_POINTER default y config HAVE_HARDLOCKUP_DETECTOR_SPARC64 @@ -44,19 +45,14 @@ index b6695303b8d4..0bb95b0aacf4 100644 + depends on HAVE_NMI + select HARDLOCKUP_DETECTOR_SPARC64 help - Sparc64 provides its own hardlockup detector implementation instead - of the generic perf one. -@@ -26,3 +27,10 @@ config HAVE_HARDLOCKUP_DETECTOR_SPARC64 - used by generic hardlockup detectors. Instead it is enabled/disabled - by the top-level watchdog interface that is common for both softlockup - and hardlockup detectors. + Sparc64 hardlockup detector is the last one developed before adding + the common infrastructure for handling hardlockup detectors. It is + always built. It does _not_ use the common command line parameters + and sysctl interface, except for /proc/sys/kernel/nmi_watchdog. + +config HARDLOCKUP_DETECTOR_SPARC64 + bool + depends on HAVE_HARDLOCKUP_DETECTOR_SPARC64 -+ -+ help -+ The custom hardlockup detector is always built when possible. diff --git a/include/linux/nmi.h b/include/linux/nmi.h index 7ee6c35d1f05..515d6724f469 100644 --- a/include/linux/nmi.h @@ -93,7 +89,7 @@ index babd2f3c8b72..a2154e753cb4 100644 #else # define WATCHDOG_HARDLOCKUP_DEFAULT 0 diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug -index 2d8d8ce7c2d7..116904e65d9f 100644 +index e94664339e28..f285e9cf967a 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1052,7 +1052,7 @@ config HAVE_HARDLOCKUP_DETECTOR_BUDDY diff -purN watchdog-buddy-hardlockup-detector-config-cleanup-v1-iter1-reference/0006-watchdog-hardlockup-Define-HARDLOCKUP_DETECTOR_ARCH.patch watchdog-buddy-hardlockup-detector-config-cleanup-v2-iter1/0006-watchdog-hardlockup-Define-HARDLOCKUP_DETECTOR_ARCH.patch --- watchdog-buddy-hardlockup-detector-config-cleanup-v1-iter1-reference/0006-watchdog-hardlockup-Define-HARDLOCKUP_DETECTOR_ARCH.patch 2023-06-16 16:42:07.769941775 +0200 +++ watchdog-buddy-hardlockup-detector-config-cleanup-v2-iter1/0006-watchdog-hardlockup-Define-HARDLOCKUP_DETECTOR_ARCH.patch 2023-06-16 16:28:53.598682426 +0200 @@ -1,7 +1,7 @@ -From 0456ed568d98ba5bba8148e4f60d769e3c5a6c7a Mon Sep 17 00:00:00 2001 +From bcf4dfab5a64ee691eb5154b1361ed59610c9387 Mon Sep 17 00:00:00 2001 From: Petr Mladek <pmladek@xxxxxxxx> Date: Tue, 6 Jun 2023 09:32:05 +0200 -Subject: [PATCH 6/6] watchdog/hardlockup: Define HARDLOCKUP_DETECTOR_ARCH +Subject: [PATCH v2 6/6] watchdog/hardlockup: Define HARDLOCKUP_DETECTOR_ARCH The HAVE_ prefix means that the code could be enabled. Add another variable for HAVE_HARDLOCKUP_DETECTOR_ARCH without this prefix. @@ -15,6 +15,7 @@ As a result HAVE_HARDLOCKUP_DETECTOR_PER on arm, x86, powerpc architectures. Signed-off-by: Petr Mladek <pmladek@xxxxxxxx> +Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx> --- arch/powerpc/Kconfig | 5 ++--- include/linux/nmi.h | 2 +- @@ -58,7 +59,7 @@ index 515d6724f469..ec808ebd36ba 100644 #endif diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug -index 116904e65d9f..97853ca54dc7 100644 +index f285e9cf967a..2c4bb72e72ad 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1056,6 +1056,7 @@ config HARDLOCKUP_DETECTOR @@ -69,7 +70,7 @@ index 116904e65d9f..97853ca54dc7 100644 select LOCKUP_DETECTOR help -@@ -1102,6 +1103,14 @@ config HARDLOCKUP_DETECTOR_BUDDY +@@ -1101,6 +1102,14 @@ config HARDLOCKUP_DETECTOR_BUDDY depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER @@ -78,8 +79,8 @@ index 116904e65d9f..97853ca54dc7 100644 + depends on HARDLOCKUP_DETECTOR + depends on HAVE_HARDLOCKUP_DETECTOR_ARCH + help -+ The arch-specific implementation of the hardlockup detector is -+ available. ++ The arch-specific implementation of the hardlockup detector will ++ be used. + # # Both the "perf" and "buddy" hardlockup detectors count hrtimer
