netdev - Re: [PATCH] inetpeer: optimizations

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4B1AD0CD.4040407@gmail.com>
Date:	Sat, 05 Dec 2009 22:29:49 +0100
From:	Jarek Poplawski <jarkao2@...il.com>
To:	Eric Dumazet <eric.dumazet@...il.com>
CC:	"David S. Miller" <davem@...emloft.net>,
	Linux Netdev List <netdev@...r.kernel.org>
Subject: Re: [PATCH] inetpeer: optimizations

Eric Dumazet wrote, On 12/05/2009 01:11 PM:

> - Use atomic_dec_and_test() in inet_putpeer()

atomic_dec_and_lock()?

>   This takes/dirties the lock only if necessary.
...

>  void inet_putpeer(struct inet_peer *p)
>  {
> -	spin_lock_bh(&inet_peer_unused_lock);
> -	if (atomic_dec_and_test(&p->refcnt)) {
> -		list_add_tail(&p->unused, &unused_peers);
> +	local_bh_disable();
> +	if (atomic_dec_and_lock(&p->refcnt, &unused_peers.lock)) {

Why not:
	if (atomic_dec_and_test(&p->refcnt)) {
		spin_lock_bh(&inet_peer_unused_lock);
		...
Jarek P.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html