On Tue, 2017-09-05 at 08:31 -0700, Jakub Kicinski wrote:
> The new TC IDR code uses GFP_KERNEL under spin lock. Which leads
> to:
>
> [ 582.621091] BUG: sleeping function called from invalid context at
> ../mm/slab.h:416
> [ 582.629721] in_atomic(): 1, irqs_disabled(): 0, pid: 3379, name: tc
> [ 582.636939] 2 locks held by tc/3379:
> [ 582.641049] #0: (rtnl_mutex){+.+.+.}, at: [<ffffffff910354ce>]
> rtnetlink_rcv_msg+0x92e/0x1400
> [ 582.650958] #1: (&(&tn->idrinfo->lock)->rlock){+.-.+.}, at:
> [<ffffffff9110a5e0>] tcf_idr_create+0x2f0/0x8e0
> [ 582.662217] Preemption disabled at:
> [ 582.662222] [<ffffffff9110a5e0>] tcf_idr_create+0x2f0/0x8e0
> [ 582.672592] CPU: 9 PID: 3379 Comm: tc Tainted: G W
> 4.13.0-rc7-debug-00648-g43503a79b9f0 #287
> [ 582.683432] Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.3.4
> 11/08/2016
> [ 582.691937] Call Trace:
> ...
> [ 582.742460] kmem_cache_alloc+0x286/0x540
> [ 582.747055] radix_tree_node_alloc.constprop.6+0x4a/0x450
> [ 582.753209] idr_get_free_cmn+0x627/0xf80
> ...
> [ 582.815525] idr_alloc_cmn+0x1a8/0x270
> ...
> [ 582.833804] tcf_idr_create+0x31b/0x8e0
> ...
>
> Try to preallocate the memory with idr_prealloc(GFP_KERNEL)
> (as suggested by Eric Dumazet), and change the allocation
> flags under spin lock.
>
> Fixes: 65a206c01e8e ("net/sched: Change act_api and act_xxx modules to use
> IDR")
> Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
> Reviewed-by: Simon Horman <simon.hor...@netronome.com>
> ---
Acked-by: Eric Dumazet <eduma...@google.com>
Not related to your patch, but it looks like idr_preload() has a bug
added in 4.11. I will send a fix to lkml.
