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author | Roman Gushchin <guro@fb.com> | 2017-11-17 15:26:45 -0800 |
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committer | Seung-Woo Kim <sw0312.kim@samsung.com> | 2020-06-03 02:36:17 +0000 |
commit | cdb2b5ce28c78720ac2afe033f1d264b8b8c13f5 (patch) | |
tree | 96c2f59379b15d903d4608dd75b0cad04bf01bf2 | |
parent | 4bf16d3d958547e6cf36d8740cd42ad1eb73f5c7 (diff) | |
download | emulator-kernel-cdb2b5ce28c78720ac2afe033f1d264b8b8c13f5.tar.gz emulator-kernel-cdb2b5ce28c78720ac2afe033f1d264b8b8c13f5.tar.bz2 emulator-kernel-cdb2b5ce28c78720ac2afe033f1d264b8b8c13f5.zip |
proc, coredump: add CoreDumping flag to /proc/pid/statustizen_6.0.m2_releasesubmit/tizen_6.0_hotfix/20201103.115106submit/tizen_6.0_hotfix/20201102.192906submit/tizen_6.0/20201029.205505submit/tizen/20200609.022747accepted/tizen/unified/20200609.153518accepted/tizen/6.0/unified/hotfix/20201103.044956accepted/tizen/6.0/unified/20201030.103032tizen_6.0_hotfixtizen_6.0accepted/tizen_6.0_unified_hotfixaccepted/tizen_6.0_unified
Right now there is no convenient way to check if a process is being
coredumped at the moment.
It might be necessary to recognize such state to prevent killing the
process and getting a broken coredump. Writing a large core might take
significant time, and the process is unresponsive during it, so it might
be killed by timeout, if another process is monitoring and
killing/restarting hanging tasks.
We're getting a significant number of corrupted coredump files on
machines in our fleet, just because processes are being killed by
timeout in the middle of the core writing process.
We do have a process health check, and some agent is responsible for
restarting processes which are not responding for health check requests.
Writing a large coredump to the disk can easily exceed the reasonable
timeout (especially on an overloaded machine).
This flag will allow the agent to distinguish processes which are being
coredumped, extend the timeout for them, and let them produce a full
coredump file.
To provide an ability to detect if a process is in the state of being
coredumped, we can expose a boolean CoreDumping flag in
/proc/pid/status.
Example:
$ cat core.sh
#!/bin/sh
echo "|/usr/bin/sleep 10" > /proc/sys/kernel/core_pattern
sleep 1000 &
PID=$!
cat /proc/$PID/status | grep CoreDumping
kill -ABRT $PID
sleep 1
cat /proc/$PID/status | grep CoreDumping
$ ./core.sh
CoreDumping: 0
CoreDumping: 1
[guro@fb.com: document CoreDumping flag in /proc/<pid>/status]
Link: http://lkml.kernel.org/r/20170928135357.GA8470@castle.DHCP.thefacebook.com
Link: http://lkml.kernel.org/r/20170920230634.31572-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[k.lewandowsk: backport mainline commit c643401218 for userspace process managers
(eg. resourced) to be able to avoid killing dead processes, breaking crash reports]
Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com>
Change-Id: I5ba2fcbf4f388be752db542e80ebca367dba618c
-rw-r--r-- | Documentation/filesystems/proc.txt | 3 | ||||
-rw-r--r-- | fs/proc/array.c | 6 |
2 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 6716413c17ba..4d34a9495584 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -176,6 +176,7 @@ read the file /proc/PID/status: VmPTE: 20 kb VmSwap: 0 kB HugetlbPages: 0 kB + CoreDumping: 0 Threads: 1 SigQ: 0/28578 SigPnd: 0000000000000000 @@ -240,6 +241,8 @@ Table 1-2: Contents of the status files (as of 4.1) VmPMD size of second level page tables VmSwap size of swap usage (the number of referred swapents) HugetlbPages size of hugetlb memory portions + CoreDumping process's memory is currently being dumped + (killing the process may lead to a corrupted core) Threads number of threads SigQ number of signals queued/max. number for queue SigPnd bitmap of pending signals for the thread diff --git a/fs/proc/array.c b/fs/proc/array.c index b6c00ce0e29e..0485d897598f 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -351,6 +351,11 @@ static void task_cpus_allowed(struct seq_file *m, struct task_struct *task) cpumask_pr_args(&task->cpus_allowed)); } +static inline void task_core_dumping(struct seq_file *m, struct mm_struct *mm) +{ + seq_printf(m, "CoreDumping:\t%d\n", !!mm->core_state); +} + int proc_pid_status(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task) { @@ -361,6 +366,7 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns, if (mm) { task_mem(m, mm); + task_core_dumping(m, mm); mmput(mm); } task_sig(m, task); |