Re: skb allocation from interrupt handler?

Il giorno mar, 08/08/2017 alle 18.17 -0400, Murali Karicheri ha
scritto:

Is there an skb_alloc function that can be used from interrupt
handler? Looks like netdev_alloc_skb()
can't be used since I see following trace with kernel hack debug
options enabled.

[  652.481713] [<c021007c>] (unwind_backtrace) from [<c020bdcc>]
(show_stack+0x10/0x14)
[  652.481725] [<c020bdcc>] (show_stack) from [<c0517780>]
(dump_stack+0x98/0xc4)
[  652.481736] [<c0517780>] (dump_stack) from [<c0256a70>]
(___might_sleep+0x1b8/0x2a4)
[  652.481746] [<c0256a70>] (___might_sleep) from [<c0939e80>]
(rt_spin_lock+0x24/0x5c)
[  652.481755] [<c0939e80>] (rt_spin_lock) from [<c07d827c>]
(__netdev_alloc_skb+0xd0/0x254)
[  652.481774] [<c07d827c>] (__netdev_alloc_skb) from [<bf23a544>]
(emac_rx_hardirq+0x374/0x554 [prueth])
[  652.481793] [<bf23a544>] (emac_rx_hardirq [prueth]) from
[<c02925dc>] (__handle_irq_event_percpu+0x9c/0x128)

This is running under RT kernel off 4.9.y

netdev_alloc_skb() passes GFP_ATOMIC to alloc_skb() so it should work
in an interrupt handler too.

-- 
Matteo Croce
per aspera ad upstream