From fc8b13740b2978b34872650cc8e928392e3758aa Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Tue, 14 Jan 2014 10:25:52 -0600 Subject: kgdb/kdb: Fix no KDB config problem Some code added to the debug_core module had KDB dependencies that it shouldn't have. Move the KDB dependent REASON back to the caller to remove the dependency in the debug core code. Update the call from the UV NMI handler to conform to the new interface. Signed-off-by: Mike Travis Reviewed-by: Hedi Berriche Cc: Russ Anderson Cc: Jason Wessel Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Link: http://lkml.kernel.org/r/20140114162551.318251993@asylum.americas.sgi.com Signed-off-by: Ingo Molnar --- kernel/debug/debug_core.c | 5 +++-- kernel/debug/debug_core.h | 2 -- 2 files changed, 3 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 7d2f35e5df2f..334b3980ffc1 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -736,7 +736,8 @@ int kgdb_nmicallback(int cpu, void *regs) return 1; } -int kgdb_nmicallin(int cpu, int trapnr, void *regs, atomic_t *send_ready) +int kgdb_nmicallin(int cpu, int trapnr, void *regs, int err_code, + atomic_t *send_ready) { #ifdef CONFIG_SMP if (!kgdb_io_ready(0) || !send_ready) @@ -750,7 +751,7 @@ int kgdb_nmicallin(int cpu, int trapnr, void *regs, atomic_t *send_ready) ks->cpu = cpu; ks->ex_vector = trapnr; ks->signo = SIGTRAP; - ks->err_code = KGDB_KDB_REASON_SYSTEM_NMI; + ks->err_code = err_code; ks->linux_regs = regs; ks->send_ready = send_ready; kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER); diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h index 572aa4f5677c..127d9bc49fb4 100644 --- a/kernel/debug/debug_core.h +++ b/kernel/debug/debug_core.h @@ -75,13 +75,11 @@ extern int kdb_stub(struct kgdb_state *ks); extern int kdb_parse(const char *cmdstr); extern int kdb_common_init_state(struct kgdb_state *ks); extern int kdb_common_deinit_state(void); -#define KGDB_KDB_REASON_SYSTEM_NMI KDB_REASON_SYSTEM_NMI #else /* ! CONFIG_KGDB_KDB */ static inline int kdb_stub(struct kgdb_state *ks) { return DBG_PASS_EVENT; } -#define KGDB_KDB_REASON_SYSTEM_NMI 0 #endif /* CONFIG_KGDB_KDB */ #endif /* _DEBUG_CORE_H_ */ -- cgit v1.2.3 From 2397efb1bb17595b35f31abb40d95074ebc04f1b Mon Sep 17 00:00:00 2001 From: Aaron Tomlin Date: Mon, 20 Jan 2014 17:34:12 +0000 Subject: sysctl: Add neg_one as a standard constraint Add neg_one to the list of standard constraints - will be used by the next patch. Signed-off-by: Aaron Tomlin Acked-by: Rik van Riel Acked-by: David Rientjes Cc: oleg@redhat.com Link: http://lkml.kernel.org/r/1390239253-24030-2-git-send-email-atomlin@redhat.com Signed-off-by: Ingo Molnar --- kernel/sysctl.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index c8da99f905cf..c398a58673a7 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -122,6 +122,7 @@ extern int blk_iopoll_enabled; static int sixty = 60; #endif +static int neg_one = -1; static int zero; static int __maybe_unused one = 1; static int __maybe_unused two = 2; -- cgit v1.2.3 From 270750dbc18a71b23d660df110e433ff9616a2d4 Mon Sep 17 00:00:00 2001 From: Aaron Tomlin Date: Mon, 20 Jan 2014 17:34:13 +0000 Subject: hung_task: Display every hung task warning When khungtaskd detects hung tasks, it prints out backtraces from a number of those tasks. Limiting the number of backtraces being printed out can result in the user not seeing the information necessary to debug the issue. The hung_task_warnings sysctl controls this feature. This patch makes it possible for hung_task_warnings to accept a special value to print an unlimited number of backtraces when khungtaskd detects hung tasks. The special value is -1. To use this value it is necessary to change types from ulong to int. Signed-off-by: Aaron Tomlin Reviewed-by: Rik van Riel Acked-by: David Rientjes Cc: oleg@redhat.com Link: http://lkml.kernel.org/r/1390239253-24030-3-git-send-email-atomlin@redhat.com [ Build warning fix. ] Signed-off-by: Ingo Molnar --- Documentation/sysctl/kernel.txt | 42 +++++++++++++++++++++++++++++++++++++++++ include/linux/sched/sysctl.h | 2 +- kernel/hung_task.c | 6 ++++-- kernel/sysctl.c | 8 +++++--- 4 files changed, 52 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 6d486404200e..4205f3c05cbe 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -33,6 +33,10 @@ show up in /proc/sys/kernel: - domainname - hostname - hotplug +- hung_task_panic +- hung_task_check_count +- hung_task_timeout_secs +- hung_task_warnings - kptr_restrict - kstack_depth_to_print [ X86 only ] - l2cr [ PPC only ] @@ -287,6 +291,44 @@ Default value is "/sbin/hotplug". ============================================================== +hung_task_panic: + +Controls the kernel's behavior when a hung task is detected. +This file shows up if CONFIG_DETECT_HUNG_TASK is enabled. + +0: continue operation. This is the default behavior. + +1: panic immediately. + +============================================================== + +hung_task_check_count: + +The upper bound on the number of tasks that are checked. +This file shows up if CONFIG_DETECT_HUNG_TASK is enabled. + +============================================================== + +hung_task_timeout_secs: + +Check interval. When a task in D state did not get scheduled +for more than this value report a warning. +This file shows up if CONFIG_DETECT_HUNG_TASK is enabled. + +0: means infinite timeout - no checking done. + +============================================================== + +hung_task_warning: + +The maximum number of warnings to report. During a check interval +When this value is reached, no more the warnings will be reported. +This file shows up if CONFIG_DETECT_HUNG_TASK is enabled. + +-1: report an infinite number of warnings. + +============================================================== + kptr_restrict: This toggle indicates whether restrictions are placed on diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h index 31e0193cb0c5..3a93f842306a 100644 --- a/include/linux/sched/sysctl.h +++ b/include/linux/sched/sysctl.h @@ -5,7 +5,7 @@ extern int sysctl_hung_task_check_count; extern unsigned int sysctl_hung_task_panic; extern unsigned long sysctl_hung_task_timeout_secs; -extern unsigned long sysctl_hung_task_warnings; +extern int sysctl_hung_task_warnings; extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 9328b80eaf14..0b9c169d577f 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -37,7 +37,7 @@ int __read_mostly sysctl_hung_task_check_count = PID_MAX_LIMIT; */ unsigned long __read_mostly sysctl_hung_task_timeout_secs = CONFIG_DEFAULT_HUNG_TASK_TIMEOUT; -unsigned long __read_mostly sysctl_hung_task_warnings = 10; +int __read_mostly sysctl_hung_task_warnings = 10; static int __read_mostly did_panic; @@ -98,7 +98,9 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout) if (!sysctl_hung_task_warnings) return; - sysctl_hung_task_warnings--; + + if (sysctl_hung_task_warnings > 0) + sysctl_hung_task_warnings--; /* * Ok, the task did not get scheduled for more than 2 minutes, diff --git a/kernel/sysctl.c b/kernel/sysctl.c index c398a58673a7..dd5b4496637e 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -122,7 +122,8 @@ extern int blk_iopoll_enabled; static int sixty = 60; #endif -static int neg_one = -1; +static int __maybe_unused neg_one = -1; + static int zero; static int __maybe_unused one = 1; static int __maybe_unused two = 2; @@ -978,9 +979,10 @@ static struct ctl_table kern_table[] = { { .procname = "hung_task_warnings", .data = &sysctl_hung_task_warnings, - .maxlen = sizeof(unsigned long), + .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_doulongvec_minmax, + .proc_handler = proc_dointvec_minmax, + .extra1 = &neg_one, }, #endif #ifdef CONFIG_COMPAT -- cgit v1.2.3