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  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]
Date:	Fri, 11 May 2012 19:30:58 +0300
From:	"Michael S. Tsirkin" <mst@...hat.com>
To:	Ian Campbell <Ian.Campbell@...rix.com>
Cc:	David Miller <davem@...emloft.net>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"eric.dumazet@...il.com" <eric.dumazet@...il.com>
Subject: Re: [PATCH RFC 1/6] skbuff: support per-page destructors in
 copy_ubufs

On Fri, May 11, 2012 at 03:08:36PM +0300, Michael S. Tsirkin wrote:
> On Fri, May 11, 2012 at 11:58:12AM +0100, Ian Campbell wrote:
> > On Fri, 2012-05-11 at 10:00 +0100, Ian Campbell wrote:
> > > I'm seeing copy_ubufs called in my remote NFS test, which I don't
> > > think I expected -- I'll investigate why this is happening today. 
> > 
> > It's tcp_transmit_skb which can (conditionally) call skb_clone
> > (backtrace below)
> 
> Interesting. I didn't realise we clone skbs on data path:
> tcp_write_xmit calls tcp_transmit_skb with clone_it flag.
> Could someone comment on why we need to clone on good path
> like this?

Hmm, it's in case we need to retransmit it later.

> -- 
> MST
--
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

Powered by blists - more mailing lists