Linux Container Development
 help / color / mirror / Atom feed
From: Dave Hansen <dave-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
To: Oren Laadan <orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
	arnd-r2nGTMty4D4@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	jeremy-TSDbQ3PG+2Y@public.gmane.org
Subject: Re: [RFC v5][PATCH 9/9] Restore open file descriprtors
Date: Mon, 22 Sep 2008 09:02:09 -0700	[thread overview]
Message-ID: <1222099329.8533.56.camel@nimitz> (raw)
In-Reply-To: <48D04B19.9060502-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>

On Tue, 2008-09-16 at 20:11 -0400, Oren Laadan wrote:
> 
> No. (this was discussed earlier already).
> 
> cr_hbuf_get() "allocates" space inside a dedicated buffer for headers
> in the checkpoint context (ctx->hbuf). It does not allocate new kernel
> memory. Instead, it returns the current position in that buffer
> ctx->hbuf[ctx->hpos], and advances ctx->hpos appropriately. On the
> other side, cr_hbuf_put() reverses that effect, reducing ctx->hpos
> accordingly.
> 
> If an error occurs, the checkpoint (or restart) operation is aborted,
> and eventually the context (ctx) will be cleaned up; at that point the
> special purpose buffer will be freed.

I think this is like claiming that my malloc() will get freed if my
applications exits, so I don't have to worry about free().  It is messy,
it makes lifetime rules and use less explicit, and it makes bugs harder
to find.  If I were a good programmer (which I'm not) I probably
wouldn't do that.

-- Dave

  parent reply	other threads:[~2008-09-22 16:02 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1221347167-9956-1-git-send-email-orenl@cs.columbia.edu>
     [not found] ` <1221347167-9956-1-git-send-email-orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2008-09-13 23:05   ` [RFC v5][PATCH 1/8] Create syscalls: sys_checkpoint, sys_restart Oren Laadan
     [not found]     ` <1221347167-9956-2-git-send-email-orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2008-09-15 20:28       ` Serge E. Hallyn
2008-09-13 23:06   ` [RFC v5][PATCH 2/8] General infrastructure for checkpoint restart Oren Laadan
2008-09-13 23:06   ` [RFC v5][PATCH 3/8] x86 support for checkpoint/restart Oren Laadan
     [not found]     ` <1221347167-9956-4-git-send-email-orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2008-09-15 21:31       ` Serge E. Hallyn
2008-09-13 23:06   ` [RFC v5][PATCH 4/8] Dump memory address space Oren Laadan
2008-09-13 23:06   ` [RFC v5][PATCH 5/8] Restore " Oren Laadan
     [not found]     ` <1221347167-9956-6-git-send-email-orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2008-09-15 19:14       ` Dave Hansen
2008-09-13 23:06   ` [RFC v5][PATCH 6/8] Checkpoint/restart: initial documentation Oren Laadan
     [not found]     ` <1221347167-9956-7-git-send-email-orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2008-09-15 20:26       ` Serge E. Hallyn
2008-09-17  6:23       ` MinChan Kim
2008-09-13 23:06   ` [RFC v5][PATCH 7/8] Infrastructure for shared objects Oren Laadan
     [not found]     ` <1221347167-9956-8-git-send-email-orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2008-09-16 16:48       ` Dave Hansen
2008-09-17  7:31         ` MinChan Kim
2008-09-16 20:54       ` Serge E. Hallyn
     [not found]     ` <20080916205459.GA7644@us.ibm.com>
     [not found]       ` <20080916205459.GA7644-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2008-09-16 21:36         ` Oren Laadan
     [not found]           ` <48D026ED.3080109-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2008-09-16 22:09             ` Serge E. Hallyn
2008-09-13 23:06   ` [RFC v5][PATCH 8/8] Dump open file descriptors Oren Laadan
     [not found]     ` <1221347167-9956-9-git-send-email-orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2008-09-14  9:51       ` Bastian Blank
2008-09-16 15:54       ` Dave Hansen
2008-09-16 16:55       ` Dave Hansen
     [not found]     ` <20080914095106.GA6300@wavehammer.waldi.eu.org>
     [not found]       ` <20080914095106.GA6300-0IJIQSrh9RL9UF0aPl6fsj8Kkb2uy4ct@public.gmane.org>
2008-09-14 15:40         ` Oren Laadan
     [not found]       ` <48CD3069.7080200@cs.columbia.edu>
     [not found]         ` <48CD3069.7080200-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2008-09-16 23:03           ` Serge E. Hallyn
     [not found]         ` <20080916230320.GA25445@us.ibm.com>
     [not found]           ` <20080916230320.GA25445-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2008-09-22 15:31             ` Dave Hansen
2008-09-13 23:06   ` [RFC v5][PATCH 9/9] Restore open file descriprtors Oren Laadan
2008-09-13 23:22   ` Oren Laadan
2008-09-17 14:16   ` [RFC v5][PATCH 0/9] Kernel based checkpoint/restart Serge E. Hallyn
2008-09-24 21:42   ` Serge E. Hallyn
     [not found] ` <1221347167-9956-3-git-send-email-orenl@cs.columbia.edu>
     [not found]   ` <1221347167-9956-3-git-send-email-orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2008-09-15 17:54     ` [RFC v5][PATCH 2/8] General infrastructure for checkpoint restart Dave Hansen
2008-09-15 17:59     ` Dave Hansen
2008-09-15 18:00     ` Dave Hansen
2008-09-15 18:02     ` Dave Hansen
2008-09-15 21:15     ` Serge E. Hallyn
     [not found]   ` <1221501750.16561.15.camel@nimitz>
2008-09-15 18:52     ` Oren Laadan
     [not found]     ` <48CEAEF2.1050901@cs.columbia.edu>
     [not found]       ` <48CEAEF2.1050901-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2008-09-15 19:13         ` Dave Hansen
2008-09-16 12:27     ` Bastian Blank
     [not found] ` <1221347167-9956-10-git-send-email-orenl@cs.columbia.edu>
     [not found]   ` <1221347167-9956-10-git-send-email-orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2008-09-16 23:08     ` [RFC v5][PATCH 9/9] Restore open file descriprtors Serge E. Hallyn
     [not found]   ` <20080916230850.GB25445@us.ibm.com>
     [not found]     ` <20080916230850.GB25445-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2008-09-17  0:11       ` Oren Laadan
     [not found]     ` <48D04B19.9060502@cs.columbia.edu>
     [not found]       ` <48D04B19.9060502-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2008-09-17  4:56         ` Serge E. Hallyn
2008-09-22 16:02         ` Dave Hansen [this message]
     [not found] ` <1221347167-9956-5-git-send-email-orenl@cs.columbia.edu>
     [not found]   ` <1221347167-9956-5-git-send-email-orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2008-09-17  6:48     ` [RFC v5][PATCH 4/8] Dump memory address space MinChan Kim
     [not found] ` <20080924214242.GA27875@us.ibm.com>
     [not found]   ` <20080924214242.GA27875-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2008-09-25 12:58     ` [RFC v5][PATCH 0/9] Kernel based checkpoint/restart Cedric Le Goater
     [not found] ` <20080917141601.GA14010@us.ibm.com>
     [not found]   ` <20080917141601.GA14010-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2008-10-08  9:59     ` Oren Laadan

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1222099329.8533.56.camel@nimitz \
    --to=dave-23vcf4htsmix0ybbhkvfkdbpr1lh4cv8@public.gmane.org \
    --cc=arnd-r2nGTMty4D4@public.gmane.org \
    --cc=containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org \
    --cc=jeremy-TSDbQ3PG+2Y@public.gmane.org \
    --cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox