From: Pavel Emelyanov <xemul-GEFAQzZX7r8dnm+yROfE0A@public•gmane.org>
To: Daniel Lezcano <dlezcano-NmTC/0ZBporQT0dZR+AlfA@public•gmane.org>
Cc: Linux Containers
<containers-qjLDD68F18O7TbgM5vRIOg@public•gmane.org>,
Linux Netdev List
<netdev-u79uwXL29TY76Z2rM5mHXA@public•gmane.org>,
Benjamin Thery <benjamin.thery-6ktuUTfB/bM@public•gmane.org>,
Denis Lunev <den-GEFAQzZX7r8dnm+yROfE0A@public•gmane.org>
Subject: Re: [PATCH 2/14][NETNS]: Generic per-net pointers.
Date: Fri, 11 Apr 2008 18:29:13 +0400 [thread overview]
Message-ID: <47FF75B9.2090508@openvz.org> (raw)
In-Reply-To: <47FF6B1B.5090106-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org>
[snip]
>> @@ -29,10 +32,21 @@ static __net_init int setup_net(struct net *net)
>> /* Must be called with net_mutex held */
>> struct pernet_operations *ops;
>> int error;
>> + struct net_generic *ng;
>>
>> atomic_set(&net->count, 1);
>> atomic_set(&net->use_count, 0);
>>
>> + error = -ENOMEM;
>> + ng = kzalloc(sizeof(struct net_generic) +
>> + INITIAL_NET_GEN_PTRS * sizeof(void *), GFP_KERNEL);
>
> Why do you need to allocate more than sizeof(struct net_generic) ?
That's just an optimization to avoid many reallocations in the
nearest future. I planned to make similar in net_assign_generic
(allocate a bit more that required), but decided to do it later
to keep net_assign_generic simpler.
Currently I have only 5 users of generic pointers (tun and vlan
you see and I have patches for ipip, ipgre and sit tunnels), so
that's enough for the first time.
[snip]
>> +int net_assign_generic(struct net *net, int id, void *data)
>> +{
>> + struct net_generic *ng, *old_ng;
>> +
>> + BUG_ON(!mutex_is_locked(&net_mutex));
>> + BUG_ON(id == 0);
>> +
>> + ng = old_ng = net->gen;
>
> shouldn't it be rcu_dereferenced ?
Nope - nobody can race with us and change this pointer, so it's
safe to get one without rcu_dereference.
Thanks,
Pavel
next prev parent reply other threads:[~2008-04-11 14:29 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-04-10 14:57 [PATCH 0/14 (3 subsets)] Make tuns and vlans devices work per-net Pavel Emelyanov
2008-04-10 15:01 ` [PATCH 1/14][NETNS]: Introduce the net-subsys id generator Pavel Emelyanov
2008-04-10 17:37 ` [Devel] " Paul Menage
2008-04-10 20:52 ` Daniel Lezcano
2008-04-11 7:56 ` Pavel Emelyanov
2008-04-10 15:06 ` [PATCH 3/14][TUN]: Introduce the tun_net structure Pavel Emelyanov
2008-04-11 1:01 ` Paul E. McKenney
2008-04-11 7:55 ` Pavel Emelyanov
2008-04-11 15:04 ` Paul E. McKenney
2008-04-11 15:45 ` Pavel Emelyanov
2008-04-11 16:27 ` Paul E. McKenney
2008-04-12 8:44 ` Pavel Emelyanov
2008-04-15 7:44 ` David Miller
2008-04-15 10:31 ` Pavel Emelyanov
[not found] ` <48048411.5030506-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2008-04-15 10:06 ` David Miller
2008-04-10 15:07 ` [PATCH 4/14][TUN]: Actually make the tun_dev_list per-net Pavel Emelyanov
2008-04-10 15:09 ` [PATCH 5/14][TUN]: Allow to register tun devices in namespace Pavel Emelyanov
2008-04-10 15:10 ` [PATCH 6/14][RTNL]: Introduce the rtnl_kill_links call Pavel Emelyanov
[not found] ` <47FE2E01.6030000-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2008-04-10 22:09 ` Daniel Hokka Zakrisson
2008-04-11 8:01 ` Pavel Emelyanov
2008-04-11 12:48 ` Patrick McHardy
2008-04-10 15:13 ` [PATCH 7/14][VLAN]: Tag vlan_group with device, not ifindex Pavel Emelyanov
2008-04-10 15:16 ` [PATCH 9/14][VLAN]: Add net argument to proc init/cleanup calls Pavel Emelyanov
[not found] ` <47FE2AD4.9080609-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2008-04-10 15:04 ` [PATCH 2/14][NETNS]: Generic per-net pointers Pavel Emelyanov
2008-04-11 13:43 ` Daniel Lezcano
[not found] ` <47FF6B1B.5090106-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org>
2008-04-11 14:29 ` Pavel Emelyanov [this message]
2008-04-10 15:14 ` [PATCH 8/14][VLAN]: Introduce the vlan_net structure Pavel Emelyanov
2008-04-10 15:18 ` [PATCH 10/14][VLAN]: Create proc files in proper net Pavel Emelyanov
2008-04-10 15:23 ` [PATCH 14/14][VLAN]: Migrate proc files when vlan device is moved to namespace Pavel Emelyanov
2008-04-10 15:19 ` [PATCH 11/14][VLAN]: Make /proc/net/vlan/conf file show per-net info Pavel Emelyanov
2008-04-10 15:20 ` [PATCH 12/14][VLAN]: Make vlan_name_type per-net Pavel Emelyanov
2008-04-10 15:22 ` [PATCH 13/14][VLAN]: Allows vlan devices registration in net namespace Pavel Emelyanov
2008-04-11 15:42 ` [PATCH 0/14 (3 subsets)] Make tuns and vlans devices work per-net Daniel Lezcano
2008-04-11 15:57 ` Pavel Emelyanov
2008-04-11 18:11 ` David Miller
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=47FF75B9.2090508@openvz.org \
--to=xemul-gefaqzzx7r8dnm+yrofe0a@public$(echo .)gmane.org \
--cc=benjamin.thery-6ktuUTfB/bM@public$(echo .)gmane.org \
--cc=containers-qjLDD68F18O7TbgM5vRIOg@public$(echo .)gmane.org \
--cc=den-GEFAQzZX7r8dnm+yROfE0A@public$(echo .)gmane.org \
--cc=dlezcano-NmTC/0ZBporQT0dZR+AlfA@public$(echo .)gmane.org \
--cc=netdev-u79uwXL29TY76Z2rM5mHXA@public$(echo .)gmane.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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