netdev - Re: [v2 PATCH 2/10] rhashtable: Eliminate unnecessary branch in rht_key

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: <20150322110755.GC1185@casper.infradead.org>
Date:	Sun, 22 Mar 2015 11:07:55 +0000
From:	Thomas Graf <tgraf@...g.ch>
To:	Herbert Xu <herbert@...dor.apana.org.au>
Cc:	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <eric.dumazet@...il.com>,
	Patrick McHardy <kaber@...sh.net>,
	Josh Triplett <josh@...htriplett.org>,
	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	netdev@...r.kernel.org
Subject: Re: [v2 PATCH 2/10] rhashtable: Eliminate unnecessary branch in
 rht_key_hashfn

On 03/22/15 at 07:04pm, Herbert Xu wrote:
> When rht_key_hashfn is called from rhashtable itself and params
> is equal to ht->p, there is no point in checking params.key_len
> and falling back to ht->p.key_len.
> 
> For some reason gcc couldn't figure out that params is the same
> as ht->p.  So let's help it by only checking params.key_len when
> it's a constant.
> 
> Signed-off-by: Herbert Xu <herbert@...dor.apana.org.au>

A comment to document this gcc hack would be nice as it's not
obvious from just reading the code. Shouldn't hold up this series
though.

Acked-by: Thomas Graf <tgraf@...g.ch>
--
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