From: chenguanyou <chenguanyou9338@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: akpm@linux-foundation.org, keescook@chromium.org,
mhocko@suse.com, lukas.bulwahn@gmail.com, vbabka@suse.cz,
gpiccoli@canonical.com, chenguanyou <chenguanyou@xiaomi.com>
Subject: [PATCH] hungtask: add filter kthread/check comm
Date: Fri, 21 May 2021 21:25:03 +0800 [thread overview]
Message-ID: <20210521132503.19740-1-chenguanyou@xiaomi.com> (raw)
Some kernel threads are always in D state, when we enable hung_task,
it will misjudge, we should skip these to narrow the scope.
exp mtk mobilephone:
root 420 420 2 0 0 kwdt_thread 0 D wdtk-0
root 421 421 2 0 0 kwdt_thread 0 D wdtk-1
root 422 422 2 0 0 kwdt_thread 0 D wdtk-2
root 423 423 2 0 0 kwdt_thread 0 D wdtk-3
root 424 424 2 0 0 kwdt_thread 0 D wdtk-4
root 425 425 2 0 0 kwdt_thread 0 D wdtk-5
root 426 426 2 0 0 kwdt_thread 0 D wdtk-6
root 427 427 2 0 0 kwdt_thread 0 D wdtk-7
root 435 435 2 0 0 mtk_lpm_monitor_thread 0 D LPM-0
root 436 436 2 0 0 mtk_lpm_monitor_thread 0 D LPM-1
root 437 437 2 0 0 mtk_lpm_monitor_thread 0 D LPM-2
root 438 438 2 0 0 mtk_lpm_monitor_thread 0 D LPM-3
root 439 439 2 0 0 mtk_lpm_monitor_thread 0 D LPM-4
root 440 440 2 0 0 mtk_lpm_monitor_thread 0 D LPM-5
root 441 441 2 0 0 mtk_lpm_monitor_thread 0 D LPM-6
root 442 442 2 0 0 mtk_lpm_monitor_thread 0 D LPM-7
Signed-off-by: chenguanyou <chenguanyou@xiaomi.com>
---
include/linux/sched/sysctl.h | 4 ++++
kernel/hung_task.c | 17 +++++++++++++++++
kernel/sysctl.c | 16 ++++++++++++++++
lib/Kconfig.debug | 24 ++++++++++++++++++++++++
4 files changed, 61 insertions(+)
diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h
index 3c31ba88aca5..e8a9a28215bf 100644
--- a/include/linux/sched/sysctl.h
+++ b/include/linux/sched/sysctl.h
@@ -14,11 +14,15 @@ extern unsigned int sysctl_hung_task_all_cpu_backtrace;
#define sysctl_hung_task_all_cpu_backtrace 0
#endif /* CONFIG_SMP */
+#define TASK_COMM_LEN 16
+
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_check_interval_secs;
extern int sysctl_hung_task_warnings;
+extern unsigned int sysctl_hung_task_filter_kthread;
+extern char sysctl_hung_task_check_comm[TASK_COMM_LEN];
int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos);
#else
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 396ebaebea3f..e018563d4882 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -23,6 +23,7 @@
#include <linux/sched/sysctl.h>
#include <trace/events/sched.h>
+#include <linux/string.h>
/*
* The number of tasks checked:
@@ -48,6 +49,16 @@ unsigned long __read_mostly sysctl_hung_task_timeout_secs = CONFIG_DEFAULT_HUNG_
*/
unsigned long __read_mostly sysctl_hung_task_check_interval_secs;
+/*
+ * Non zero means no checking kthread
+ */
+unsigned int __read_mostly sysctl_hung_task_filter_kthread = CONFIG_DEFAULT_HUNG_TASK_FILTER_KTHREAD;
+
+/*
+ * Only one
+ */
+char __read_mostly sysctl_hung_task_check_comm[TASK_COMM_LEN] = CONFIG_DEFAULT_HUNG_TASK_CHECK_COMM;
+
int __read_mostly sysctl_hung_task_warnings = 10;
static int __read_mostly did_panic;
@@ -88,6 +99,12 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
{
unsigned long switch_count = t->nvcsw + t->nivcsw;
+ if (unlikely(strlen(sysctl_hung_task_check_comm) && !strstr(t->comm, sysctl_hung_task_check_comm)))
+ return;
+
+ if (unlikely(sysctl_hung_task_filter_kthread && t->flags & PF_KTHREAD))
+ return;
+
/*
* Ensure the task is not frozen.
* Also, skip vfork and any other user process that freezer should skip.
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 62fbd09b5dc1..1daede87c88d 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2519,6 +2519,22 @@ static struct ctl_table kern_table[] = {
.proc_handler = proc_dointvec_minmax,
.extra1 = &neg_one,
},
+ {
+ .procname = "hung_task_filter_kthread",
+ .data = &sysctl_hung_task_filter_kthread,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ },
+ {
+ .procname = "hung_task_check_comm",
+ .data = &sysctl_hung_task_check_comm,
+ .maxlen = TASK_COMM_LEN,
+ .mode = 0644,
+ .proc_handler = proc_dostring,
+ },
#endif
#ifdef CONFIG_RT_MUTEXES
{
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 2c7f46b366f1..6eab8cf0c37f 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1101,6 +1101,30 @@ config DEFAULT_HUNG_TASK_TIMEOUT
A timeout of 0 disables the check. The default is two minutes.
Keeping the default should be fine in most cases.
+config DEFAULT_HUNG_TASK_FILTER_KTHREAD
+ int "Default filter kthread for hung task"
+ depends on DETECT_HUNG_TASK
+ range 0 1
+ default 0
+ help
+ This option controls filter kthread used to determine when
+ a kernel task has become "state=TASK_UNINTERRUPTIBLE" and should be skip.
+
+ It can be adjusted at runtime via the kernel.hung_task_filter_kthread
+ sysctl or by writing a value to
+ /proc/sys/kernel/hung_task_filter_kthread.
+
+ A filter of 1 disables the check
+
+config DEFAULT_HUNG_TASK_CHECK_COMM
+ string "Default check only one comm"
+ depends on DETECT_HUNG_TASK
+ default ""
+ help
+ It can be adjusted at runtime via the kernel.hung_task_check_comm
+ sysctl or by writing a value to
+ /proc/sys/kernel/hung_task_check_comm.
+
config BOOTPARAM_HUNG_TASK_PANIC
bool "Panic (Reboot) On Hung Tasks"
depends on DETECT_HUNG_TASK
--
2.17.1
next reply other threads:[~2021-05-21 13:25 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-21 13:25 chenguanyou [this message]
2021-05-21 16:37 ` [PATCH] hungtask: add filter kthread/check comm Randy Dunlap
-- strict thread matches above, loose matches on Subject: below --
2021-05-21 13:25 chenguanyou
2021-05-22 21:51 ` Andrew Morton
[not found] ` <CAHS3RMWjuB98TzvcYyQ0qtNYOxDeM7W1YmyqDYs=H-cn-VsVdw@mail.gmail.com>
2021-05-25 7:26 ` Michal Hocko
2021-05-19 12:13 chenguanyou
2021-05-19 13:06 ` Michal Hocko
2021-05-19 17:53 ` Randy Dunlap
[not found] ` <CAHS3RMVYbHTzD6JnOmE331qSbcnvuYnBe0jraNuuLc0Z2NnStg@mail.gmail.com>
2021-05-21 8:31 ` Michal Hocko
2021-05-18 11:16 chenguanyou
2021-05-19 11:28 ` Vlastimil Babka
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210521132503.19740-1-chenguanyou@xiaomi.com \
--to=chenguanyou9338@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=chenguanyou@xiaomi.com \
--cc=gpiccoli@canonical.com \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lukas.bulwahn@gmail.com \
--cc=mhocko@suse.com \
--cc=vbabka@suse.cz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.