Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Christian Brauner <christian.brauner@canonical.com>
Date:   Fri, 2 Nov 2018 10:46:03 +0100
To:     Joel Fernandes <joel@joelfernandes.org>
Cc:     Aleksa Sarai <cyphar@cyphar.com>,
        Daniel Colascione <dancol@google.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Tim Murray <timmurray@google.com>,
        Suren Baghdasaryan <surenb@google.com>, ebiederm@xmission.com,
        luto@amacapital.net, serge@hallyn.com
Subject: Re: [RFC PATCH] Implement /proc/pid/kill
Message-ID: <20181102094602.z5otkwrqtchpuhfm@gmail.com>
References: <CAKOZuesKVic-5epRj8XcFNR_63SgvaPcbjDQuSLxNrEfS=O=Jg@mail.gmail.com>
 <20181030204501.jnbe7dyqui47hd2x@yavin>
 <20181030214243.GB32621@google.com>
 <20181030222339.ud4wfp75tidowuo4@yavin>
 <20181030223343.GB105735@joelaf.mtv.corp.google.com>
 <CAKOZueuBdY_b=CVk29pzn0NAt9sJtzr6yqx9Y00WCppCm1JFWQ@mail.gmail.com>
 <CAPP7u0VQqDvFr=-52+Tmv_K=vT730wG7w9VQqJggsXTPFvaUBQ@mail.gmail.com>
 <20181031025655.yz7lfhswk7igb3ty@yavin>
 <CAEXW_YQxWcQGZHrwhwsyu7GCk+WSap=tb0-asTsG8sTFmjE--g@mail.gmail.com>
 <20181101204059.GA102756@google.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <20181101204059.GA102756@google.com>
User-Agent: NeoMutt/20180716
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, Nov 01, 2018 at 01:40:59PM -0700, Joel Fernandes wrote:
> On Tue, Oct 30, 2018 at 09:24:00PM -0700, Joel Fernandes wrote:
> > On Tue, Oct 30, 2018 at 7:56 PM, Aleksa Sarai <cyphar@cyphar.com> wrote:
> > > On 2018-10-31, Christian Brauner <christian.brauner@canonical.com> wrote:
> > >> > I think Aleksa's larger point is that it's useful to treat processes
> > >> > as other file-descriptor-named, poll-able, wait-able resources.
> > >> > Consistency is important. A process is just another system resource,
> > >> > and like any other system resource, you should be open to hold a file
> > >> > descriptor to it and do things to that process via that file
> > >> > descriptor. The precise form of this process-handle FD is up for
> > >> > debate. The existing /proc/$PID directory FD is a good candidate for a
> > >> > process handle FD, since it does almost all of what's needed. But
> > >> > regardless of what form a process handle FD takes, we need it. I don't
> > >> > see a case for continuing to treat processes in a non-unixy,
> > >> > non-file-descriptor-based manner.
> > >>
> > >> That's what I'm proposing in the API for which I'm gathering feedback.
> > >> I have presented parts of this in various discussions at LSS Europe last week
> > >> and will be at LPC.
> > >> We don't want to rush an API like this though. It was tried before in
> > >> other forms
> > >> and these proposals didn't make it.
> > >
> > > :+1: on a well thought-out and generic proposal. As we've discussed
> > > elsewhere, this is an issue that really would be great to (finally)
> > > solve.
> > 
> > Excited to see this and please count me in for discussions around this. thanks.
> > 
> 
> Just a quick question, is there a track planned at LPC for discussing this
> new proposal or topics around/related to the proposal?
> 
> If not, should that be planned?

There isn't currently one planned but I'm happy to have a hallway track
session around this.

But note, I think not all relevant people are going to be there (e.g.
Andy). File descriptors for processes seems interesting to a lot of
people so I'm going to send out a pitch of the idea I have and see how
much I'm going to get yelled at latest on Tuesday. Even if it just
triggers a design discussion.
I have been urged by people I pitched this to to send it to lkml
already. Sorry for the delay and the initial non-transparency. The only
reason I didn't do it right away was to ensure that this idea is not
completely crazy. :) (Eric probably still thinks I am though. :))
It's just that I'm at a conference and I want to have a nicer writeup of
this. Given the speed with which this is all coming I have given up on
preparing a first set of patches. :)

Christian