From: Pavel Emelyanov <xemul@parallels.com>
To: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Andrew Vagin <avagin@parallels.com>,
mtk.manpages@gmail.com, David Howells <dhowells@redhat.com>,
linux-api@vger.kernel.org, Oleg Nesterov <oleg@redhat.com>,
linux-kernel@vger.kernel.org, criu@openvz.org,
Cyrill Gorcunov <gorcunov@openvz.org>,
Andrey Wagin <avagin@gmail.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org, Dave Jones <davej@redhat.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: Re: [CRIU] [PATCH 3/3] signalfd: add ability to read siginfo-s without dequeuing signals (v2)
Date: Mon, 11 Feb 2013 18:53:11 +0400 [thread overview]
Message-ID: <511905D7.3040209@parallels.com> (raw)
In-Reply-To: <CAK1hOcMepaOD80GOvUv1xz3xibTG_iKMK-w7698K6KfRmcKGeA@mail.gmail.com>
On 02/11/2013 06:46 PM, Denys Vlasenko wrote:
> On Mon, Feb 11, 2013 at 11:59 AM, Andrew Vagin <avagin@parallels.com> wrote:
>>>> I suppose I had wondered along similar lines, but in a slightly
>>>> different direction: would the use of a /proc interface to get the
>>>> queued signals make some sense?
>>>
>>> I think that /proc interface beats adding magic flags and magic semantic
>>> to [p]read.
>>>
>>> It also has the benefit of being human-readable. You don't need
>>> to write a special C program to "cat /proc/$$/foo".
>>>
>>> Andrey, I know that it is hard to let go of the code you invested time
>>> and efforts in creating. But this isn't the last patch, is it?
>>> You will need to retrieve yet more data for process checkpointing.
>>> When you start working on the next patch for it, consider trying
>>> /proc approach.
>>
>> I don't think that we need to convert siginfo into a human readable format
>> in kernel.
>
> My point is that bolting hacks onto various bits of kernel API
> in order to support process checkpointing makes those APIs
> (their in-kernel implementation) ridden with special cases
> and harder to support in the future.
>
> Process checkpointing needs to bite the bullet and
> create its own API instead.
This is bad approach as well. What we should do is come up with a sane
API that makes sense without the checkpoint-restore project _when_ _possible_.
> Whether it would be a /proc/PID/checkpoint or a
> ptrace(PTRACE_GET_CHKPOINT_DATA) is another question.
Thanks,
Pavel
next prev parent reply other threads:[~2013-02-11 14:53 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-22 10:15 [PATCH 0/3] signalfd: a kernel interface for dumping pending signals Andrey Vagin
2013-01-22 10:15 ` [PATCH 1/3] signal: add a helper for dequeuing signals from a specified queue Andrey Vagin
2013-02-05 12:00 ` [PATCH 1/3] signal: add a helper for dequeuing signals from a specified queue (v2) Andrey Vagin
2013-01-22 10:15 ` [PATCH 2/3] signalfd: add ability to choose a private or shared queue Andrey Vagin
2013-02-07 18:17 ` Oleg Nesterov
2013-02-08 0:35 ` Michael Kerrisk (man-pages)
2013-02-08 19:12 ` Oleg Nesterov
2013-01-22 10:15 ` [PATCH 3/3] signalfd: add ability to read siginfo-s without dequeuing signals Andrey Vagin
2013-01-29 19:03 ` [PATCH 3/3] signalfd: add ability to read siginfo-s without dequeuing signals (v2) Andrey Vagin
[not found] ` <CAKgNAkgQA=zK=2ZnytPFU=DH6jr0sja0iy6K+j6c7unheLFniQ@mail.gmail.com>
2013-02-02 7:15 ` Andrey Wagin
2013-02-07 17:34 ` Oleg Nesterov
2013-02-07 21:13 ` Andrey Wagin
2013-02-08 0:51 ` Michael Kerrisk (man-pages)
2013-02-08 19:10 ` Oleg Nesterov
2013-02-08 20:15 ` Michael Kerrisk (man-pages)
2013-02-09 18:22 ` Oleg Nesterov
2013-02-09 22:53 ` Michael Kerrisk (man-pages)
2013-02-10 10:04 ` [CRIU] " Andrew Vagin
2013-02-11 16:47 ` Oleg Nesterov
2013-02-10 10:07 ` Andrew Vagin
2013-02-11 9:29 ` Denys Vlasenko
2013-02-11 10:59 ` [CRIU] " Andrew Vagin
2013-02-11 14:46 ` Denys Vlasenko
2013-02-11 14:53 ` Pavel Emelyanov [this message]
2013-02-11 17:25 ` Denys Vlasenko
2013-02-12 14:50 ` Pavel Emelyanov
2013-01-23 4:19 ` [PATCH 0/3] signalfd: a kernel interface for dumping pending signals Michael Kerrisk (man-pages)
2013-01-23 11:03 ` Andrew Vagin
2013-01-23 12:11 ` Michael Kerrisk (man-pages)
2013-01-23 13:03 ` Andrew Vagin
2013-02-07 18:20 ` Oleg Nesterov
2013-02-08 0:36 ` Michael Kerrisk (man-pages)
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