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Date:   Wed, 24 May 2023 16:10:23 +0200
From:   Oleg Nesterov <oleg@redhat.com>
To:     "Eric W. Biederman" <ebiederm@xmission.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
Message-ID: <20230524141022.GA19091@redhat.com>
References: <20230522025124.5863-1-michael.christie@oracle.com>
 <20230522025124.5863-4-michael.christie@oracle.com>
 <20230522123029.GA22159@redhat.com>
 <cfca7764-d210-6df9-e182-2c093101c6cf@oracle.com>
 <20230522174757.GC22159@redhat.com>
 <20230523121506.GA6562@redhat.com>
 <87bkib6nxr.fsf@email.froward.int.ebiederm.org>
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On 05/23, Eric W. Biederman wrote:
>
> I want to point out that we need to consider not just SIGKILL, but
> SIGABRT that causes a coredump, as well as the process peforming
> an ordinary exit(2).  All of which will cause get_signal to return
> SIGKILL in this context.

Yes, but probably SIGABRT/exit doesn't really differ from SIGKILL wrt
vhost_worker().

> It is probably not the worst thing in the world, but what this means
> is now if you pass a copy of the vhost file descriptor to another
> process the vhost_worker will persist, and thus the process will persist
> until that copy of the file descriptor is closed.

Hadn't thought about it.

I am fighting with internal bugzillas today, will try to write another
email tomorrow.

But before that, I would like to have an answer to my "main" question in
my previois email. Otherwise I am still not sure I understand what exactly
we need to fix.

Oleg.