From: "Eric W. Biederman" <ebiederm@xmission.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Mike Christie <michael.christie@oracle.com>,
linux@leemhuis.info, nicolas.dichtel@6wind.com, axboe@kernel.dk,
torvalds@linux-foundation.org, linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org, mst@redhat.com,
sgarzare@redhat.com, jasowang@redhat.com, stefanha@redhat.com,
brauner@kernel.org
Subject: Re: [PATCH 3/3] fork, vhost: Use CLONE_THREAD to fix freezer/ps regression
Date: Thu, 25 May 2023 10:30:04 -0500 [thread overview]
Message-ID: <87y1lcxwcj.fsf@email.froward.int.ebiederm.org> (raw)
In-Reply-To: <20230525115512.GA9229@redhat.com> (Oleg Nesterov's message of "Thu, 25 May 2023 13:55:13 +0200")
Oleg Nesterov <oleg@redhat.com> writes:
> On 05/24, Eric W. Biederman wrote:
>>
>> Oleg Nesterov <oleg@redhat.com> writes:
>>
>> > Yes, but probably SIGABRT/exit doesn't really differ from SIGKILL wrt
>> > vhost_worker().
>>
>> Actually I think it reveals that exiting with SIGABRT will cause
>> a deadlock.
>>
>> coredump_wait will wait for all of the threads to reach
>> coredump_task_exit. Meanwhile vhost_worker is waiting for
>> all of the other threads to reach exit_files to close their
>> file descriptors.
>
> Indeed, I didn't think about this.
>
>
> So why do we actually need CLONE_THREAD ? Can't vhost_worker() be a kernel thread?
>
> kthread_create() won't be convenient, but how about kernel_thread() ? it inherits
> mm/cgroups/rlimits/etc, kthread_stop() should work just fine.
Basically with no patches that is where Linus's kernel is.
User complained about the new thread showing up in ps. So the
exploration of how we could use CLONE_THREAD instead of what is
currently merged began.
Eric
next prev parent reply other threads:[~2023-05-25 15:31 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-22 2:51 [PATCH 0/3] vhost: Fix freezer/ps regressions Mike Christie
2023-05-22 2:51 ` [PATCH 1/3] signal: Don't always put SIGKILL in shared_pending Mike Christie
2023-05-23 15:30 ` Eric W. Biederman
2023-05-22 2:51 ` [PATCH 2/3] signal: Don't exit for PF_USER_WORKER tasks Mike Christie
2023-05-22 2:51 ` [PATCH 3/3] fork, vhost: Use CLONE_THREAD to fix freezer/ps regression Mike Christie
2023-05-22 12:30 ` Oleg Nesterov
2023-05-22 17:00 ` Mike Christie
2023-05-22 17:47 ` Oleg Nesterov
2023-05-23 12:15 ` Oleg Nesterov
2023-05-23 15:57 ` Eric W. Biederman
2023-05-24 14:10 ` Oleg Nesterov
2023-05-24 14:44 ` Eric W. Biederman
2023-05-25 11:55 ` Oleg Nesterov
2023-05-25 15:30 ` Eric W. Biederman [this message]
2023-05-25 16:20 ` Linus Torvalds
2023-05-27 9:49 ` Eric W. Biederman
2023-05-27 16:12 ` Linus Torvalds
2023-05-28 1:17 ` Eric W. Biederman
2023-05-28 1:21 ` Linus Torvalds
2023-05-29 11:19 ` Oleg Nesterov
2023-05-29 16:09 ` michael.christie
2023-05-29 17:46 ` Oleg Nesterov
2023-05-29 17:54 ` Oleg Nesterov
2023-05-29 19:03 ` Mike Christie
2023-05-29 19:35 ` Mike Christie
2023-05-29 19:46 ` michael.christie
2023-05-30 2:48 ` Eric W. Biederman
2023-05-30 2:38 ` Eric W. Biederman
2023-05-30 15:34 ` Mike Christie
2023-05-31 3:30 ` Mike Christie
2023-05-29 16:11 ` michael.christie
2023-05-30 14:15 ` Christian Brauner
2023-05-30 17:55 ` Oleg Nesterov
2023-05-30 15:01 ` Eric W. Biederman
2023-05-31 5:22 ` Jason Wang
2023-05-24 0:02 ` Mike Christie
2023-05-25 16:15 ` Mike Christie
2023-05-28 1:41 ` Eric W. Biederman
2023-05-28 19:29 ` Mike Christie
2023-05-31 5:22 ` Jason Wang
2023-05-31 7:25 ` Oleg Nesterov
2023-05-31 8:17 ` Jason Wang
2023-05-31 9:14 ` Oleg Nesterov
2023-06-01 2:44 ` Jason Wang
2023-06-01 7:43 ` Oleg Nesterov
2023-06-02 5:03 ` Jason Wang
2023-06-02 17:58 ` Oleg Nesterov
2023-06-02 20:07 ` Linus Torvalds
2023-06-05 14:20 ` Oleg Nesterov
2023-05-22 19:40 ` Michael S. Tsirkin
2023-05-23 15:39 ` Eric W. Biederman
2023-05-23 15:48 ` Mike Christie
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