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| author | Aaron Tomlin | 2014-01-20 18:34:13 +0100 |
|---|---|---|
| committer | Ingo Molnar | 2014-01-25 12:13:33 +0100 |
| commit | 270750dbc18a71b23d660df110e433ff9616a2d4 (patch) | |
| tree | 9b0400fc3713bd02d31835e8d0315cfbd7ccd912 /kernel | |
| parent | sysctl: Add neg_one as a standard constraint (diff) | |
| download | kernel-qcow2-linux-270750dbc18a71b23d660df110e433ff9616a2d4.tar.gz kernel-qcow2-linux-270750dbc18a71b23d660df110e433ff9616a2d4.tar.xz kernel-qcow2-linux-270750dbc18a71b23d660df110e433ff9616a2d4.zip | |
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 <atomlin@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
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 <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/hung_task.c | 6 | ||||
| -rw-r--r-- | kernel/sysctl.c | 8 |
2 files changed, 9 insertions, 5 deletions
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 |