From: "H. Peter Anvin" <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
To: Matt Helsley <matthltc-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
Cc: Randy Dunlap
<randy.dunlap-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>,
Serge Hallyn
<serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>,
Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>,
Albert Cahalan <acahalan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
Containers
<containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>,
Nathan Lynch <nathanl-V7BBcbaFuwjMbYB6QlFGEg@public.gmane.org>,
Dan Smith <danms-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>,
Sukadev Bhattiprolu
<sukadev-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>,
Roland McGrath <roland-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH 11/11][v15]: Document sys_eclone
Date: Sun, 04 Jul 2010 21:10:42 -0700 [thread overview]
Message-ID: <4C315B42.1020201@zytor.com> (raw)
In-Reply-To: <20100704233951.GK3338-52DBMbEzqgQ/wnmkkaCWp/UQ3DHhIser@public.gmane.org>
On 07/04/2010 04:39 PM, Matt Helsley wrote:
>>
>> 1. can you implement it for i386 (register starved) using eclone?
>
> That's a very good question. I'm going to punt on a direct answer for
> now. Instead, I wonder if it's even worth enabling vfork through eclone.
> vfork is rarely used, is supported by the "old" clone syscall, and any
> old code adapted to use eclone for vfork would need significant
> changes because of vfork's specialness. (A consequence of the way vfork
> borrows page tables and must avoid clobbering parent's registers..)
>
vfork is its own system call for a reason. We used to do it with
sys_clone, and it turned out to be a mess. Doing it in a separate
system call -- even though the internals are largely the same -- is cleaner.
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
next prev parent reply other threads:[~2010-07-05 4:10 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-03 20:32 [PATCH 00/11][v15]: Implement eclone() system call Sukadev Bhattiprolu
[not found] ` <1278189164-28408-1-git-send-email-sukadev-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2010-07-03 20:32 ` [PATCH 01/11][v15]: Factor out code to allocate pidmap page Sukadev Bhattiprolu
2010-07-03 20:32 ` [PATCH 02/11][v15]: Have alloc_pidmap() return actual error code Sukadev Bhattiprolu
2010-07-03 20:32 ` [PATCH 03/11][v15]: Define set_pidmap() function Sukadev Bhattiprolu
2010-07-03 20:32 ` [PATCH 04/11][v15]: Add target_pids parameter to alloc_pid() Sukadev Bhattiprolu
2010-07-03 20:32 ` [PATCH 05/11][v15]: Add target_pids parameter to copy_process() Sukadev Bhattiprolu
2010-07-03 20:32 ` [PATCH 06/11][v15]: Check invalid clone flags Sukadev Bhattiprolu
2010-07-03 20:32 ` [PATCH 07/11][v15]: Define do_fork_with_pids() Sukadev Bhattiprolu
2010-07-03 20:32 ` [PATCH 08/11][v15]: Implement sys_eclone for x86 (32,64) Sukadev Bhattiprolu
2010-07-03 20:32 ` [PATCH 09/11][v15]: Implement sys_eclone for s390 Sukadev Bhattiprolu
2010-07-03 20:32 ` [PATCH 10/11][v15]: Implement sys_eclone for powerpc Sukadev Bhattiprolu
2010-07-03 20:32 ` [PATCH 11/11][v15]: Document sys_eclone Sukadev Bhattiprolu
[not found] ` <1278189164-28408-12-git-send-email-sukadev-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2010-07-03 23:41 ` Albert Cahalan
[not found] ` <AANLkTinM1jqG-9Mgbzft8bALGri7ZpzU9ZcPbMTe4fvW-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-07-04 23:39 ` Matt Helsley
[not found] ` <20100704233951.GK3338-52DBMbEzqgQ/wnmkkaCWp/UQ3DHhIser@public.gmane.org>
2010-07-05 0:45 ` Albert Cahalan
[not found] ` <AANLkTilTGvFTkjy8vi8N8msB7koEp0r7SnpPqJkVN4XA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-07-05 10:34 ` Arnd Bergmann
[not found] ` <201007051234.40943.arnd-r2nGTMty4D4@public.gmane.org>
2010-07-06 22:25 ` Sukadev Bhattiprolu
[not found] ` <20100706222554.GA7648-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2010-07-11 9:00 ` Albert Cahalan
[not found] ` <AANLkTilJMi8cXSlbG8towQFFAQpuuJjO9kDXWOfEu_EJ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-07-12 18:02 ` Matt Helsley
2010-07-12 21:54 ` Sukadev Bhattiprolu
[not found] ` <20100712215456.GA23721-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2010-07-13 6:48 ` Albert Cahalan
[not found] ` <AANLkTikXDsv9CoV_EU48bunLD1wCh3w7HVdpo84rJtJg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-07-20 22:13 ` Sukadev Bhattiprolu
[not found] ` <20100720221357.GA2440-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2010-07-21 19:51 ` Albert Cahalan
2010-07-05 4:10 ` H. Peter Anvin [this message]
[not found] ` <4C315B42.1020201-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
2010-07-06 4:11 ` Albert Cahalan
[not found] ` <AANLkTimWBFbcRyf5tvA9Lork13gAJtCAdUg_ZS3PzbI0-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-07-06 15:14 ` Oren Laadan
2010-07-05 4:18 ` Oren Laadan
[not found] ` <4C315D2D.6000107-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2010-07-06 3:59 ` Albert Cahalan
[not found] ` <AANLkTinr_2u-_0S2UvMDc7hOE_JOVIOjGtVo9Tzuk21E-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-07-06 13:12 ` Serge E. Hallyn
2010-07-06 15:12 ` Oren Laadan
[not found] ` <4C3347CA.8060703-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2010-07-06 22:23 ` H. Peter Anvin
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