netdev - Re: [PATCH] net: bcmgenet: fix throughtput regression with TSO autosizing

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: <54EF580A.4060000@gmail.com>
Date:	Thu, 26 Feb 2015 09:29:46 -0800
From:	Florian Fainelli <f.fainelli@...il.com>
To:	Eric Dumazet <eric.dumazet@...il.com>,
	Jaedon Shin <jaedon.shin@...il.com>
CC:	netdev@...r.kernel.org
Subject: Re: [PATCH] net: bcmgenet: fix throughtput regression with TSO autosizing

On 26/02/15 09:27, Eric Dumazet wrote:
> On Thu, 2015-02-26 at 20:05 +0900, Jaedon Shin wrote:
>> This patch prevents the performance degradation of xmit after
>> 605ad7f ("tcp: refine TSO autosizing").
>>
>> Signed-off-by: Jaedon Shin <jaedon.shin@...il.com>
>> ---
>>  drivers/net/ethernet/broadcom/genet/bcmgenet.c | 3 +++
>>  1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
>> index ff83c46b..87eeff0 100644
>> --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
>> +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
>> @@ -1310,6 +1310,9 @@ static netdev_tx_t bcmgenet_xmit(struct sk_buff *skb, struct net_device *dev)
>>  out:
>>  	spin_unlock_irqrestore(&ring->lock, flags);
>>  
>> +	if (index != DESC_INDEX)
>> +		skb_orphan(skb);
>> +
> 
> Hmpff...
> 
> Can you elaborate on the regression ?
> 
> Is it because NIC delays TX completion irq or something ?
> 
> bcmgenet_poll() only drains TX packets on ring16 (DESC_INDEC)
> 
> Other tx completions seem to run from hard irq context (bcmgenet_isr1())
> 
> Your patch seems to imply a bug in hard irq signaling/handling.

Yes, there is a bug in how packets transmitted are reclaimed, I will
submit a fix for this shortly.
--
Florian
--
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