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From: Johannes Berg <johannes@sipsolutions.net>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Marc MERLIN <marc@merlins.org>,
	David Miller <davem@davemloft.net>,
	Larry.Finger@lwfinger.net, bhutchings@solarflare.com,
	linux-wireless@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: 3.7.8/amd64 full interrupt hangs due to iwlwifi under big nfs copies out
Date: Wed, 20 Feb 2013 18:01:26 +0100	[thread overview]
Message-ID: <1361379686.8629.41.camel@jlt4.sipsolutions.net> (raw)
In-Reply-To: <1361379331.19353.189.camel@edumazet-glaptop> (sfid-20130220_175537_373410_F2F98F44)

On Wed, 2013-02-20 at 08:55 -0800, Eric Dumazet wrote:

> > > Unless wifi speed reaches 10Gbps, following patch should do the trick
> > > 
> > > 
> > > diff --git a/drivers/net/wireless/iwlwifi/dvm/rx.c b/drivers/net/wireless/iwlwifi/dvm/rx.c
> > > index a4eed20..77a3ee3 100644
> > > --- a/drivers/net/wireless/iwlwifi/dvm/rx.c
> > > +++ b/drivers/net/wireless/iwlwifi/dvm/rx.c
> > > @@ -750,7 +750,12 @@ static void iwlagn_pass_packet_to_mac80211(struct iwl_priv *priv,
> > >  	/* Dont use dev_alloc_skb(), we'll have enough headroom once
> > >  	 * ieee80211_hdr pulled.
> > >  	 */
> > > -	skb = alloc_skb(128, GFP_ATOMIC);
> > > +	fraglen = 128;
> > > +	/* if we use order-1 pages, copy to get better TCP performance */
> > > +	if (rxb->truesize > PAGE_SIZE)
> > > +		fraglen = max_t(unsigned, fraglen, len);
> > > +
> > > +	skb = alloc_skb(fraglen, GFP_ATOMIC);
> > 
> > Hmm, I don't quite understand -- that's not doing any copy?
> > 
> > FWIW if you do the copy you should not "steal" the pages, then they'd be
> > recycled in the RX ring right away.
> 
> Code should just works, please read the following lines in the same
> function....

FWIW, I think just using order-0 pages and turning 8k A-MSDUs off by
default makes more sense, A-MSDU is rarely used to begin with ...

Also, if we copy larger frames here, we should also take into account
the (variable) 802.11 header length to avoid copying into a position
where the IP header ends up being unaligned.

johannes

  parent reply	other threads:[~2013-02-20 17:01 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-29 16:38 3.2.8/amd64 full interrupt hangs and deadlocks under big network copies (page allocation failure) Marc MERLIN
     [not found] ` <20120311183244.GA14001@merlins.org>
     [not found]   ` <20120329053111.GD24933@merlins.org>
     [not found]     ` <20120329163800.GH24933-xnduUnryOU1AfugRpC6u6w@public.gmane.org>
     [not found]       ` <20120329053111.GD24933-xnduUnryOU1AfugRpC6u6w@public.gmane.org>
2012-03-29 16:41         ` Marc MERLIN
2012-03-29 18:09 ` Ben Hutchings
     [not found]   ` <1333044575.2656.1.camel-/LGg1Z1CJKReKY3V0RtoKmatzQS1i7+A3tAM5lWOD0I@public.gmane.org>
2012-03-29 21:19     ` Marc MERLIN
2012-04-09 17:20   ` Marc MERLIN
2012-04-09 18:12     ` David Miller
     [not found]       ` <20120409.141241.1216091936509309354.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2012-04-09 18:36         ` Marc MERLIN
2012-04-09 18:37           ` David Miller
2012-04-09 18:58             ` Larry Finger
2012-04-09 19:11               ` Eric Dumazet
2012-04-09 19:34                 ` David Miller
     [not found]                   ` <20120409.153452.1284163346306246866.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2012-04-09 19:46                     ` Marc MERLIN
2012-04-10  3:56                   ` Eric Dumazet
2012-04-10  5:11                     ` Marc MERLIN
2012-04-10  6:11                       ` Eric Dumazet
2012-04-11  5:27                         ` Marc MERLIN
     [not found]                           ` <20120411052733.GA17352-xnduUnryOU1AfugRpC6u6w@public.gmane.org>
2012-04-11  5:43                             ` Eric Dumazet
2012-04-11  6:30                               ` [PATCH] tcp: avoid order-1 allocations on wifi and tx path Eric Dumazet
2012-04-11  7:38                                 ` Eric Dumazet
2012-04-11 14:12                                   ` David Miller
2012-04-11 14:11                                 ` David Miller
2012-04-11  6:08                           ` [PATCH] net: allow pskb_expand_head() to get maximum tailroom Eric Dumazet
2012-04-11 14:11                             ` David Miller
2012-07-15 21:59                           ` 3.4.4/amd64 full interrupt hangs under big nfs copies Marc MERLIN
2012-07-16  6:18                             ` Eric Dumazet
2012-07-16 15:18                               ` Marc MERLIN
2012-07-16 16:21                                 ` Eric Dumazet
2012-07-16 17:17                                   ` Marc MERLIN
2013-02-19  4:05                                   ` 3.7.8/amd64 full interrupt hangs due to iwlwifi under big nfs copies out Marc MERLIN
2013-02-19  5:17                                     ` Eric Dumazet
2013-02-19  5:26                                       ` Marc MERLIN
2013-02-19 10:03                                       ` Johannes Berg
2013-02-19 16:18                                         ` Marc MERLIN
2013-02-19 16:36                                           ` Eric Dumazet
2013-02-19 16:21                                         ` Eric Dumazet
2013-02-20  9:12                                           ` Johannes Berg
2013-02-20  9:15                                             ` Johannes Berg
2013-02-20 15:11                                               ` Eric Dumazet
2013-02-20 16:20                                                 ` Johannes Berg
     [not found]                                                   ` <1361377243.8629.34.camel-8Nb76shvtaUJvtFkdXX2HixXY32XiHfO@public.gmane.org>
2013-02-20 16:55                                                     ` Eric Dumazet
2013-02-20 16:59                                                       ` Johannes Berg
2013-02-20 17:39                                                         ` Eric Dumazet
2013-02-20 17:01                                                       ` Johannes Berg [this message]
2013-02-20 17:24                                                         ` Eric Dumazet
2013-02-20 18:16                                                           ` Johannes Berg
2013-02-20 19:17                                                             ` Eric Dumazet
2013-02-20 19:58                                                               ` Johannes Berg
2013-02-20 20:14                                                                 ` Eric Dumazet
2013-02-20 20:27                                                                   ` Johannes Berg
2013-02-20 20:09                                                 ` Johannes Berg
2013-02-23  6:14                                               ` Marc MERLIN
2013-02-26 20:54                                                 ` Johannes Berg
     [not found]                                                   ` <1361912099.8440.21.camel-8Nb76shvtaUJvtFkdXX2HixXY32XiHfO@public.gmane.org>
2013-06-18 16:52                                                     ` Eric Dumazet
2013-06-18 17:04                                                       ` Johannes Berg
2013-06-19 13:09                                                         ` Stanislaw Gruszka

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