From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: Michal Hocko <mhocko@kernel.org>
Cc: David Rientjes <rientjes@google.com>,
linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH] mm, oom: disable dump_tasks by default
Date: Fri, 6 Sep 2019 19:46:10 +0900 [thread overview]
Message-ID: <20ec856d-0f1e-8903-dbe0-bbc8b7a1847a@i-love.sakura.ne.jp> (raw)
In-Reply-To: <20190905140833.GB3838@dhcp22.suse.cz>
On 2019/09/05 23:08, Michal Hocko wrote:
> On Thu 05-09-19 22:39:47, Tetsuo Handa wrote:
> [...]
>> There is nothing that prevents users from enabling oom_dump_tasks by sysctl.
>> But that requires a solution for OOM stalling problem.
>
> You can hardly remove stalling if you are not reducing the amount of
> output or get it into a different context. Whether the later is
> reasonable is another question but you are essentially losing "at the
> OOM event state".
>
I am not losing "at the OOM event state". Please find "struct oom_task_info"
(for now) embedded into "struct task_struct" which holds "at the OOM event state".
And my patch moves "printk() from dump_tasks()" from OOM context to WQ context.
Thus, I do remove stalling by defer printing of "struct oom_task_info" until
the OOM killer sends SIGKILL and the OOM reaper starts reclaiming memory.
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -639,6 +639,21 @@ struct wake_q_node {
struct wake_q_node *next;
};
+/* Memory usage and misc info as of invocation of OOM killer. */
+struct oom_task_info {
+ struct list_head list;
+ unsigned int seq;
+ char comm[TASK_COMM_LEN];
+ pid_t pid;
+ uid_t uid;
+ pid_t tgid;
+ unsigned long total_vm;
+ unsigned long mm_rss;
+ unsigned long pgtables_bytes;
+ unsigned long swapents;
+ int score_adj;
+};
+
struct task_struct {
#ifdef CONFIG_THREAD_INFO_IN_TASK
/*
@@ -1260,7 +1275,7 @@ struct task_struct {
#ifdef CONFIG_MMU
struct task_struct *oom_reaper_list;
#endif
- struct list_head oom_victim_list;
+ struct oom_task_info oom_task_info;
#ifdef CONFIG_VMAP_STACK
struct vm_struct *stack_vm_area;
#endif
next prev parent reply other threads:[~2019-09-06 10:46 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-03 14:45 [RFC PATCH] mm, oom: disable dump_tasks by default Michal Hocko
2019-09-03 15:02 ` Qian Cai
2019-09-03 15:13 ` Michal Hocko
2019-09-03 15:32 ` Qian Cai
2019-09-03 19:12 ` Michal Hocko
2019-09-05 16:10 ` Qian Cai
2019-09-03 20:52 ` Tetsuo Handa
2019-09-04 5:40 ` Michal Hocko
2019-09-04 20:04 ` David Rientjes
2019-09-05 13:39 ` Tetsuo Handa
2019-09-05 14:08 ` Michal Hocko
2019-09-06 10:46 ` Tetsuo Handa [this message]
2019-09-06 11:02 ` Michal Hocko
2019-09-06 11:11 ` Tetsuo Handa
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=20ec856d-0f1e-8903-dbe0-bbc8b7a1847a@i-love.sakura.ne.jp \
--to=penguin-kernel@i-love.sakura.ne.jp \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=rientjes@google.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).