From: Eric Dumazet <eric.dumazet@gmail.com>
To: Jarek Poplawski <jarkao2@gmail.com>
Cc: David Miller <davem@davemloft.net>,
jesse@nicira.com, netdev@vger.kernel.org
Subject: Re: [PATCH net-next-2.6] net: inet_add_protocol() can use cmpxchg()
Date: Thu, 09 Sep 2010 14:57:38 +0200 [thread overview]
Message-ID: <1284037058.2589.169.camel@edumazet-laptop> (raw)
In-Reply-To: <20100909095920.GB8404@ff.dom.local>
Le jeudi 09 septembre 2010 à 09:59 +0000, Jarek Poplawski a écrit :
> Btw, I wonder if for readability and debuging it shouldn't be made
> generic as rcu_cmpxchg_pointer() etc.?
There are a lot of things to do in this area (with proper __rcu sparse
annotations, this can be not very readable ...)
/**
* rcu_cmpxchg - atomic compare and exchange, SMP & rcu safe
* @p: pointer to value
* @old: old value
* @new: new value
*
* Equivalent to :
* ATOMIC_BEGIN
* ret = *p;
* if (ret == old)
* rcu_assign_pointer(*p, new);
* ATOMIC_END
* return ret;
*
* cmpxpchg() contains full memory barriers, so can be used
* in rcu write side without additional smp_wmb() barrier
*/
#define rcu_cmpxchg(p, old, new) cmpxchg(p, old, new)
const struct net_protocol __rcu *
inet_protos[MAX_INET_PROTOS] __read_mostly;
...
return !rcu_cmpxchg(&inet_protos[hash],
NULL,
(const struct net_protocol __force __rcu *)prot) ?
0 : -1;
...
next prev parent reply other threads:[~2010-09-09 12:57 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-08 22:56 [PATCH net-next-2.6] net: inet_add_protocol() can use cmpxchg() Eric Dumazet
2010-09-08 23:49 ` Jesse Gross
2010-09-09 4:30 ` David Miller
2010-09-09 6:42 ` Jarek Poplawski
2010-09-09 6:55 ` Eric Dumazet
2010-09-09 7:09 ` Jarek Poplawski
2010-09-09 7:24 ` Jarek Poplawski
2010-09-09 9:08 ` Jarek Poplawski
2010-09-09 9:23 ` Eric Dumazet
2010-09-09 9:42 ` Jarek Poplawski
2010-09-09 9:59 ` Jarek Poplawski
2010-09-09 12:57 ` Eric Dumazet [this message]
2010-09-09 15:38 ` Jarek Poplawski
2010-09-09 5:23 ` Eric Dumazet
2010-09-09 4:31 ` 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=1284037058.2589.169.camel@edumazet-laptop \
--to=eric.dumazet@gmail.com \
--cc=davem@davemloft.net \
--cc=jarkao2@gmail.com \
--cc=jesse@nicira.com \
--cc=netdev@vger.kernel.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