Re: [PATCH] NETLINK_UESTABLISHED notifier event

[Mike Christie <michaelc@xxxxxxxxxxx>]

Herbert Xu wrote:
> Dmitry Yusupov <dmitry_yus@xxxxxxxxx> wrote:
> > * netlink alloc_skb() now uses sk_allocation instead of hard-coded
> > GFP_KERNEL
>
> Why? We never set it to anything else for netlink.
It is due to where it is being used. open-iscsi uses netlink
sockets for communication in a block (scsi specificically)
driver that has pushed much of its code to usersapce. Forcing
open-iscsi to use GFP_KERNEL causes a couple of problems. The
worst would be where a GFP_KERNEL allocation causes a write,
and that write is to an iscsi disk that open-iscsi is managing.
The write could then hit the same code path and cause another
GFP_KERNEL allocation and we could loop like that until the
system locks up.