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]
Date:	Wed, 27 Aug 2014 13:43:23 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	brouer@...hat.com
Cc:	netdev@...r.kernel.org, therbert@...gle.com, jhs@...atatu.com,
	hannes@...essinduktion.org, edumazet@...gle.com,
	jeffrey.t.kirsher@...el.com, rusty@...tcorp.com.au,
	dborkman@...hat.com
Subject: Re: [PATCH 0/2] Get rid of ndo_xmit_flush

From: Jesper Dangaard Brouer <brouer@...hat.com>
Date: Wed, 27 Aug 2014 14:19:18 +0200

> On Mon, 25 Aug 2014 16:34:58 -0700 (PDT)
> David Miller <davem@...emloft.net> wrote:
> 
>> Given Jesper's performance numbers, it's not the way to go.
>> 
>> Instead, go with a signalling scheme via new boolean skb->xmit_more.
>> 
>> This has several advantages:
>> 
>> 1) Nearly trivial driver support, just protect the tail pointer
>>    update with the skb->xmit_more check.
>> 
>> 2) No extra indirect calls in the non-deferral cases.
> 
> Even-though it is obvious that this new API skb->xmit_more will not
> hurt performance, especially given skb->xmit_more is always 0 in this
> kernel, I've still run my pktgen performance tests.
> 
> Compared to baseline[1]: (averaged 5609929 pps) (details below signature)
>  * (1/5609929*10^9)-(1/5603728*10^9) = -0.197ns
> 
> As expected, this API does not hurt performance (as -0.197ns is below
> our accuracy levels).
> 
> [1] http://thread.gmane.org/gmane.linux.network/327254/focus=327838

Thanks for validating Jesper :-)
--
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

Powered by blists - more mailing lists