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Date:   Wed, 22 May 2019 17:48:25 +0200
From:   Christian Brauner <christian@brauner.io>
To:     Daniel Colascione <dancol@google.com>
Cc:     Minchan Kim <minchan@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-mm <linux-mm@kvack.org>, Michal Hocko <mhocko@suse.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Tim Murray <timmurray@google.com>,
        Joel Fernandes <joel@joelfernandes.org>,
        Suren Baghdasaryan <surenb@google.com>,
        Shakeel Butt <shakeelb@google.com>,
        Sonny Rao <sonnyrao@google.com>,
        Brian Geffon <bgeffon@google.com>, Jann Horn <jannh@google.com>
Subject: Re: [RFC 0/7] introduce memory hinting API for external process
Message-ID: <20190522154823.hu77qbjho5weado5@brauner.io>
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On Wed, May 22, 2019 at 08:17:23AM -0700, Daniel Colascione wrote:
> On Wed, May 22, 2019 at 7:52 AM Christian Brauner <christian@brauner.io> wrote:
> > I'm not going to go into yet another long argument. I prefer pidfd_*.
> 
> Ok. We're each allowed our opinion.
> 
> > It's tied to the api, transparent for userspace, and disambiguates it
> > from process_vm_{read,write}v that both take a pid_t.
> 
> Speaking of process_vm_readv and process_vm_writev: both have a
> currently-unused flags argument. Both should grow a flag that tells
> them to interpret the pid argument as a pidfd. Or do you support
> adding pidfd_vm_readv and pidfd_vm_writev system calls? If not, why
> should process_madvise be called pidfd_madvise while process_vm_readv
> isn't called pidfd_vm_readv?

Actually, you should then do the same with process_madvise() and give it
a flag for that too if that's not too crazy.

Christian