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From: David Miller <davem@davemloft.net>
To: rdreier@cisco.com
Cc: netdev@vger.kernel.org, shemminger@linux-foundation.org,
	rusty@rustcorp.com.au, jgarzik@pobox.com
Subject: Re: [PATCH RFX]: napi_struct V3
Date: Sat, 28 Jul 2007 22:30:49 -0700 (PDT)	[thread overview]
Message-ID: <20070728.223049.78711264.davem@davemloft.net> (raw)
In-Reply-To: <ada6444y2nd.fsf@cisco.com>

From: Roland Dreier <rdreier@cisco.com>
Date: Sat, 28 Jul 2007 08:21:58 -0700

>  > Another area of consternation are drivers that were using
>  > netif_rx_reschedule(), as that interface was removed because it
>  > doesn't fit well with the caller managing the dev->quota et al.  I
>  > left race conditions in the drivers that were using that interface,
>  > but they should still basically work nonetheless.
> 
> ...but this is a problem for IPoIB.  The underlying IB stuff only
> allows us to register what is essentially a one-shot edge-triggered
> interrupt.  So there is a race between calling netif_rx_complete() and
> calling ib_req_notify_cq() (which enables the interrupt), since the
> interrupt might never happen if a packet arrives between the two calls.

You will see further along in the thread that we have found
a locking sequence by which this issue can be resolved.

Please read the full thread and the most recent patch before
coming to conclusions :-)

      reply	other threads:[~2007-07-29  5:30 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-07-24  4:07 [PATCH RFX]: napi_struct V3 David Miller
2007-07-24  4:47 ` Rusty Russell
2007-07-24  5:47   ` David Miller
2007-07-24  6:21     ` Rusty Russell
2007-07-25  0:45       ` David Miller
2007-07-25  1:15         ` Rusty Russell
2007-07-25  1:47           ` David Miller
2007-07-25  2:33             ` Rusty Russell
2007-07-25  4:29               ` David Miller
2007-07-25  5:09                 ` Rusty Russell
2007-07-25  5:12                   ` David Miller
2007-07-25  5:10             ` David Miller
2007-07-24  7:12 ` Francois Romieu
2007-07-24  7:33   ` Jeff Garzik
2007-07-24  7:35   ` David Miller
2007-07-28 15:21 ` Roland Dreier
2007-07-29  5:30   ` David Miller [this message]

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