> -----Original Message----- > From: David Miller [mailto:[email protected]] > Sent: Tuesday, January 14, 2014 5:32 PM > To: Haiyang Zhang > Cc: [email protected]; KY Srinivasan; [email protected]; > [email protected]; [email protected]; driverdev- > [email protected] > Subject: Re: [PATCH net-next] hyperv: Add support for physically discontinuous > receive buffer > > From: Haiyang Zhang <[email protected]> > Date: Thu, 9 Jan 2014 14:24:47 -0800 > > > This will allow us to use bigger receive buffer, and prevent > > allocation failure due to fragmented memory. > > > > Signed-off-by: Haiyang Zhang <[email protected]> > > Reviewed-by: K. Y. Srinivasan <[email protected]> > > Not until you start using paged SKBs in netvsc_recv_callback. > > Whatever fragmention you think you're avoiding in the hyperv layer, you're > still > going to get from the: > > skb = netdev_alloc_skb_ip_align(net, packet->total_data_buflen); > > call there. > > This change makes no sense in isolation, therefore I'm not applying it until > you > also include the appropriate changes to avoid the same exact fragmentation > issue in netvsc_drv.c as stated above.
The receive buffer currently requires multiple MB of physically continuous memory, and may fail to be allocated when memory is fragmented. The patch is created for this issue. The SKB buffer is usually less than 1500 bytes or up to several KB with jumbo frame, so it's much less sensitive to fragmented memory. I will work on another patch to use SKB buffer with discontinuous pages. Could you accept this patch separately? Thanks, - Haiyang _______________________________________________ devel mailing list [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
