| Message ID | 20200507214624.21911-1-gpiccoli@canonical.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases | expand |
On Thu, 7 May 2020 18:46:24 -0300 "Guilherme G. Piccoli" <gpiccoli@canonical.com> wrote: > After a recent change introduced by Vlastimil's series [0], kernel is > able now to handle sysctl parameters on kernel command line; also, the > series introduced a simple infrastructure to convert legacy boot > parameters (that duplicate sysctls) into sysctl aliases. > > This patch converts the watchdog parameters softlockup_panic and > {hard,soft}lockup_all_cpu_backtrace to use the new alias infrastructure. > It fixes the documentation too, since the alias only accepts values 0 > or 1, not the full range of integers. We also took the opportunity here > to improve the documentation of the previously converted hung_task_panic > (see the patch series [0]) and put the alias table in alphabetical order. We have a lot of sysctls. What is the motivation for converting these particular ones?
On Thu, May 7, 2020 at 8:06 PM Andrew Morton <akpm@linux-foundation.org> wrote: > We have a lot of sysctls. What is the motivation for converting these > particular ones? No stronger motivation than a regular clean-up - I just liked the infrastructure provided by Vlastmil and thought in using it. I know we have plenty of sysctls, but not all of them have identical/duplicate boot params, so I went with the obvious ones, that I use more. Cheers, Guilherme
On 5/7/20 11:46 PM, Guilherme G. Piccoli wrote: > After a recent change introduced by Vlastimil's series [0], kernel is > able now to handle sysctl parameters on kernel command line; also, the > series introduced a simple infrastructure to convert legacy boot > parameters (that duplicate sysctls) into sysctl aliases. > > This patch converts the watchdog parameters softlockup_panic and > {hard,soft}lockup_all_cpu_backtrace to use the new alias infrastructure. > It fixes the documentation too, since the alias only accepts values 0 > or 1, not the full range of integers. We also took the opportunity here > to improve the documentation of the previously converted hung_task_panic > (see the patch series [0]) and put the alias table in alphabetical order. > > [0] lore.kernel.org/lkml/20200427180433.7029-1-vbabka@suse.cz > > Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com> Ah, so I did miss some, as the Documentation file doesn't mention there is also a sysctl for those parameters. Maybe it should? Anyway, thanks. Acked-by: Vlastimil Babka <vbabka@suse.cz>
On 5/8/20 1:06 AM, Andrew Morton wrote: > On Thu, 7 May 2020 18:46:24 -0300 "Guilherme G. Piccoli" <gpiccoli@canonical.com> wrote: > >> After a recent change introduced by Vlastimil's series [0], kernel is >> able now to handle sysctl parameters on kernel command line; also, the >> series introduced a simple infrastructure to convert legacy boot >> parameters (that duplicate sysctls) into sysctl aliases. >> >> This patch converts the watchdog parameters softlockup_panic and >> {hard,soft}lockup_all_cpu_backtrace to use the new alias infrastructure. >> It fixes the documentation too, since the alias only accepts values 0 >> or 1, not the full range of integers. We also took the opportunity here >> to improve the documentation of the previously converted hung_task_panic >> (see the patch series [0]) and put the alias table in alphabetical order. > > We have a lot of sysctls. What is the motivation for converting these > particular ones? It's not converting sysctls, it's converting legacy boot parameters that have a sysctl counterpart. There's not a lot of those, and new ones shouldn't be added with the generic infrastructure in place. I would have converted them myself if I found them :)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 5a44c1bf85e7..d9197499aad1 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1435,7 +1435,7 @@ hardlockup_all_cpu_backtrace= [KNL] Should the hard-lockup detector generate backtraces on all cpus. - Format: <integer> + Format: 0 | 1 hashdist= [KNL,NUMA] Large hashes allocated during boot are distributed across NUMA nodes. Defaults on @@ -1503,7 +1503,7 @@ hung_task_panic= [KNL] Should the hung task detector generate panics. - Format: <integer> + Format: 0 | 1 A value of 1 instructs the kernel to panic when a hung task is detected. The default value is controlled @@ -4643,9 +4643,9 @@ softlockup_panic= [KNL] Should the soft-lockup detector generate panics. - Format: <integer> + Format: 0 | 1 - A nonzero value instructs the soft-lockup detector + A value of 1 instructs the soft-lockup detector to panic the machine when a soft-lockup occurs. It is also controlled by the kernel.softlockup_panic sysctl and CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC, which is the @@ -4654,7 +4654,7 @@ softlockup_all_cpu_backtrace= [KNL] Should the soft-lockup detector generate backtraces on all cpus. - Format: <integer> + Format: 0 | 1 sonypi.*= [HW] Sony Programmable I/O Control Device driver See Documentation/admin-guide/laptops/sonypi.rst diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 15030784566c..5b405f32971d 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -1720,8 +1720,11 @@ struct sysctl_alias { * parameter. */ static const struct sysctl_alias sysctl_aliases[] = { - {"numa_zonelist_order", "vm.numa_zonelist_order" }, - {"hung_task_panic", "kernel.hung_task_panic" }, + {"hardlockup_all_cpu_backtrace", "kernel.hardlockup_all_cpu_backtrace" }, + {"hung_task_panic", "kernel.hung_task_panic" }, + {"numa_zonelist_order", "vm.numa_zonelist_order" }, + {"softlockup_all_cpu_backtrace", "kernel.softlockup_all_cpu_backtrace" }, + {"softlockup_panic", "kernel.softlockup_panic" }, { } }; diff --git a/kernel/watchdog.c b/kernel/watchdog.c index fa5aacbfd000..1b939532fcc1 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -50,6 +50,11 @@ struct cpumask watchdog_cpumask __read_mostly; unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask); #ifdef CONFIG_HARDLOCKUP_DETECTOR + +# ifdef CONFIG_SMP +int __read_mostly sysctl_hardlockup_all_cpu_backtrace; +# endif /* CONFIG_SMP */ + /* * Should we panic when a soft-lockup or hard-lockup occurs: */ @@ -82,17 +87,6 @@ static int __init hardlockup_panic_setup(char *str) } __setup("nmi_watchdog=", hardlockup_panic_setup); -# ifdef CONFIG_SMP -int __read_mostly sysctl_hardlockup_all_cpu_backtrace; - -static int __init hardlockup_all_cpu_backtrace_setup(char *str) -{ - sysctl_hardlockup_all_cpu_backtrace = !!simple_strtol(str, NULL, 0); - return 1; -} -__setup("hardlockup_all_cpu_backtrace=", hardlockup_all_cpu_backtrace_setup); -# endif /* CONFIG_SMP */ - atomic_t hardlockup_detected = ATOMIC_INIT(0); static inline void flush_hardlockup_messages(void) @@ -183,6 +177,10 @@ static void lockup_detector_update_enable(void) #define SOFTLOCKUP_RESET ULONG_MAX +#ifdef CONFIG_SMP +int __read_mostly sysctl_softlockup_all_cpu_backtrace; +#endif + /* Global variables, exported for sysctl */ unsigned int __read_mostly softlockup_panic = CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE; @@ -198,13 +196,6 @@ static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts); static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved); static unsigned long soft_lockup_nmi_warn; -static int __init softlockup_panic_setup(char *str) -{ - softlockup_panic = simple_strtoul(str, NULL, 0); - return 1; -} -__setup("softlockup_panic=", softlockup_panic_setup); - static int __init nowatchdog_setup(char *str) { watchdog_user_enabled = 0; @@ -226,17 +217,6 @@ static int __init watchdog_thresh_setup(char *str) } __setup("watchdog_thresh=", watchdog_thresh_setup); -#ifdef CONFIG_SMP -int __read_mostly sysctl_softlockup_all_cpu_backtrace; - -static int __init softlockup_all_cpu_backtrace_setup(char *str) -{ - sysctl_softlockup_all_cpu_backtrace = !!simple_strtol(str, NULL, 0); - return 1; -} -__setup("softlockup_all_cpu_backtrace=", softlockup_all_cpu_backtrace_setup); -#endif - static void __lockup_detector_cleanup(void); /*
After a recent change introduced by Vlastimil's series [0], kernel is able now to handle sysctl parameters on kernel command line; also, the series introduced a simple infrastructure to convert legacy boot parameters (that duplicate sysctls) into sysctl aliases. This patch converts the watchdog parameters softlockup_panic and {hard,soft}lockup_all_cpu_backtrace to use the new alias infrastructure. It fixes the documentation too, since the alias only accepts values 0 or 1, not the full range of integers. We also took the opportunity here to improve the documentation of the previously converted hung_task_panic (see the patch series [0]) and put the alias table in alphabetical order. [0] lore.kernel.org/lkml/20200427180433.7029-1-vbabka@suse.cz Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com> --- This patch is based on linux-next/akpm branch, at d0f3f6070c3a. Thanks in advance for reviews! Cheers, Guilherme .../admin-guide/kernel-parameters.txt | 10 ++--- fs/proc/proc_sysctl.c | 7 +++- kernel/watchdog.c | 38 +++++-------------- 3 files changed, 19 insertions(+), 36 deletions(-)