From: "Shimoda, Yoshihiro" <yoshihiro.shimoda.uh@renesas.com>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org, linux-sh@vger.kernel.org
Subject: Re: [PATCH v3 6/6] net: sh_eth: use NAPI
Date: Tue, 15 May 2012 09:46:25 +0000 [thread overview]
Message-ID: <4FB225F1.20407@renesas.com> (raw)
In-Reply-To: <20120515.010753.2012331320750491448.davem@davemloft.net>
2012/05/15 14:07, David Miller wrote:
> From: "Shimoda, Yoshihiro" <yoshihiro.shimoda.uh@renesas.com>
> Date: Tue, 15 May 2012 13:47:44 +0900
>
>> 2012/05/15 7:50, David Miller wrote:
>>> You need strict synchronization between your TX queueing and TX
>>> liberation flows. So that queue stop and wake are only performed
>>> at the correct moment.
>>
>> I will add netif_queue_stopped() in the sh_eth_poll().
>
> That doesn't fix the bug. What if someone transmits a packet and
> fills the TX queue between the netif_queue_stopped() test and the
> call to netif_wake_queue()?
>
> Adding another test doesn't create the necessary synchronization.
>
Thank you for the reply again.
I will modify the code as the following. Is it correct?
if (txfree_num) {
netif_tx_lock(ndev);
if (netif_queue_stopped(ndev))
netif_wake_queue(ndev);
netif_tx_unlock(ndev);
}
Best regards,
Yoshihiro Shimoda
WARNING: multiple messages have this Message-ID (diff)
From: "Shimoda, Yoshihiro" <yoshihiro.shimoda.uh@renesas.com>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org, linux-sh@vger.kernel.org
Subject: Re: [PATCH v3 6/6] net: sh_eth: use NAPI
Date: Tue, 15 May 2012 18:46:25 +0900 [thread overview]
Message-ID: <4FB225F1.20407@renesas.com> (raw)
In-Reply-To: <20120515.010753.2012331320750491448.davem@davemloft.net>
2012/05/15 14:07, David Miller wrote:
> From: "Shimoda, Yoshihiro" <yoshihiro.shimoda.uh@renesas.com>
> Date: Tue, 15 May 2012 13:47:44 +0900
>
>> 2012/05/15 7:50, David Miller wrote:
>>> You need strict synchronization between your TX queueing and TX
>>> liberation flows. So that queue stop and wake are only performed
>>> at the correct moment.
>>
>> I will add netif_queue_stopped() in the sh_eth_poll().
>
> That doesn't fix the bug. What if someone transmits a packet and
> fills the TX queue between the netif_queue_stopped() test and the
> call to netif_wake_queue()?
>
> Adding another test doesn't create the necessary synchronization.
>
Thank you for the reply again.
I will modify the code as the following. Is it correct?
if (txfree_num) {
netif_tx_lock(ndev);
if (netif_queue_stopped(ndev))
netif_wake_queue(ndev);
netif_tx_unlock(ndev);
}
Best regards,
Yoshihiro Shimoda
next prev parent reply other threads:[~2012-05-15 9:46 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-14 6:47 [PATCH v3 6/6] net: sh_eth: use NAPI Shimoda, Yoshihiro
2012-05-14 6:47 ` Shimoda, Yoshihiro
2012-05-14 22:50 ` David Miller
2012-05-14 22:50 ` David Miller
2012-05-15 4:47 ` Shimoda, Yoshihiro
2012-05-15 4:47 ` Shimoda, Yoshihiro
2012-05-15 5:07 ` David Miller
2012-05-15 5:07 ` David Miller
2012-05-15 9:46 ` Shimoda, Yoshihiro [this message]
2012-05-15 9:46 ` Shimoda, Yoshihiro
2012-05-15 13:43 ` Francois Romieu
2012-05-15 13:43 ` Francois Romieu
2012-05-15 17:05 ` David Miller
2012-05-15 17:05 ` David Miller
2012-05-15 18:29 ` Francois Romieu
2012-05-15 18:29 ` Francois Romieu
2012-05-16 2:24 ` Shimoda, Yoshihiro
2012-05-16 2:24 ` Shimoda, Yoshihiro
2012-05-16 2:14 ` Shimoda, Yoshihiro
2012-05-16 2:14 ` Shimoda, Yoshihiro
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