From: Oleg Nesterov <oleg@redhat.com>
To: Pavel Emelyanov <xemul@parallels.com>
Cc: Tejun Heo <tj@kernel.org>, Pedro Alves <pedro@codesourcery.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Cyrill Gorcunov <gorcunov@openvz.org>,
James Bottomley <jbottomley@parallels.com>
Subject: Re: [RFC][PATCH 0/3] fork: Add the ability to create tasks with given pids
Date: Fri, 25 Nov 2011 17:22:20 +0100 [thread overview]
Message-ID: <20111125162220.GA17173@redhat.com> (raw)
In-Reply-To: <4ECF6AA0.80006@parallels.com>
On 11/25, Pavel Emelyanov wrote:
>
> The proposal is to implement the PR_RESERVE_PID prctl which allocates and puts a
> pid on the current. The subsequent fork() uses this pid,
Oh. This is subjective, yes, but this doesn't clean to me.
Amd why?? On the running system PR_RESERVE_PID can obviously fail anyway.
It only helps to avoid the race with another fork.
> * one more field on struct pid is OK, since it size doesn't change (32 bit level is
> anyway not required, it's OK to reduce on down to 16 bits)
Even if sizeof is the same, the new member and the code which plays
with ->flags doesn't make the things better ;)
> * yes, we have +1 member on task_struct :(
Yes, and this task_struct->rsv_pid acts as implicit parameter for the
next clone(). Doesn't look very nice to me. Plus the code complications.
> Oleg, Tejun, do you agree with such an approach?
If set_last_pid doesn't work, I'd prefer CLONE_CHILD_USEPIDS.
Oleg.
next prev parent reply other threads:[~2011-11-25 16:27 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-17 11:41 [RFC][PATCH 0/3] fork: Add the ability to create tasks with given pids Pavel Emelyanov
2011-11-17 11:42 ` [PATCH 1/3] pids: Make alloc_pid return error Pavel Emelyanov
2011-11-17 11:42 ` [PATCH 2/3] pids: Split alloc_pidmap into parts Pavel Emelyanov
2011-11-17 11:43 ` [PATCH 3/3] pids: Make it possible to clone tasks with given pids Pavel Emelyanov
2011-11-17 15:32 ` Oleg Nesterov
2011-11-17 15:49 ` Pavel Emelyanov
2011-11-17 16:00 ` Oleg Nesterov
2011-11-17 17:28 ` Linus Torvalds
2011-11-17 19:04 ` Oleg Nesterov
2011-11-17 18:36 ` Oleg Nesterov
2011-11-18 10:05 ` Pavel Emelyanov
2011-11-17 15:49 ` [RFC][PATCH 0/3] fork: Add the ability to create " Oleg Nesterov
2011-11-17 16:01 ` Pavel Emelyanov
2011-11-17 16:02 ` Oleg Nesterov
2011-11-18 23:30 ` Tejun Heo
2011-11-21 9:15 ` Pavel Emelyanov
2011-11-21 22:50 ` Tejun Heo
2011-11-22 11:11 ` Pavel Emelyanov
2011-11-22 12:04 ` Pedro Alves
2011-11-22 15:33 ` Tejun Heo
2011-11-23 16:20 ` Pedro Alves
2011-11-23 16:24 ` Tejun Heo
2011-11-23 17:26 ` Oleg Nesterov
2011-11-23 17:37 ` Tejun Heo
2011-11-23 18:19 ` Pavel Emelyanov
2011-11-23 20:14 ` Pavel Emelyanov
2011-11-24 17:31 ` Oleg Nesterov
2011-11-25 10:14 ` Pavel Emelyanov
2011-11-25 16:22 ` Oleg Nesterov [this message]
2011-11-25 16:44 ` Pavel Emelyanov
2011-11-25 16:54 ` Oleg Nesterov
2011-11-25 17:03 ` Pavel Emelyanov
2011-11-25 22:36 ` Pedro Alves
2011-11-27 16:24 ` [RFC][PATCH 0/3] fork: Add the ability to create tasks with?given pids Oleg Nesterov
2011-11-27 9:41 ` [RFC][PATCH 0/3] fork: Add the ability to create tasks with given pids Konstantin Khlebnikov
2011-11-27 17:34 ` Oleg Nesterov
2011-11-27 18:47 ` Tejun Heo
2011-11-28 10:38 ` Pavel Emelyanov
2011-11-28 16:25 ` Tejun Heo
2011-11-22 15:23 ` Tejun Heo
2011-11-22 15:29 ` Tejun Heo
2011-11-22 16:30 ` Pavel Emelyanov
2011-11-22 16:44 ` Linus Torvalds
2011-11-22 19:29 ` Pavel Emelyanov
2012-01-26 23:28 ` Kay Sievers
2011-11-22 21:16 ` Oleg Nesterov
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