linux-kernel - Re: Regression associated with commit c8628155ece3

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: <1345694593.5904.87.camel@edumazet-glaptop>
Date:	Thu, 23 Aug 2012 06:03:13 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Larry Finger <Larry.Finger@...inger.net>
Cc:	Neal Cardwell <ncardwell@...gle.com>,
	"David S. Miller" <davem@...emloft.net>,
	John W Linville <linville@...driver.com>,
	linux-wireless <linux-wireless@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: Regression associated with commit c8628155ece3 - "tcp: reduce
 out_of_order memory use"

On Wed, 2012-08-22 at 16:33 -0500, Larry Finger wrote:
> On 08/22/2012 12:15 AM, Eric Dumazet wrote:
> >
> > This particular commit is the start of a patches batch that ended in the
> > generic TCP coalescing mechanism.
> >
> > It is known to have problem on drivers doing skb_clone() in their rx
> > path.
> >
> > Current kernels should be ok, because coalescing doesnt happen if the
> > destination skb is cloned (skb_cloned(to) in skb_try_coalesce())
> 
> The skb_clone() call is not the source of the problem for r8712u, as it is only 
> used when a memory allocation fails, which is not happening. The suggestion did 
> lead to another patch that I had been preparing. The initial allocation of RX 
> buffers used a size of 30720 bytes, while 9100 is sufficient to allow 
> aggregation. Upon reducing the buffer size, the driver now works for me. I am 
> now awaiting tests by the OP on the Red Hat bugzilla before sending the patch 
> upstream.
> 
> So far, no ideas for the problem in connecting to WPA1 networks.
> 

Changing the allocation size removes the problem ? thats really strange.

If you try different sizes in the 9100-30720 range, can you pinpoint the
failure threshold ?



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/