Re: [patch] Real-Time Preemption, -RT-2.6.11-rc3-V0.7.38-01

Stephen Smalley
2005-02-09T12:56:48Z

On Tue, 2005-02-08 at 16:58, William Weston wrote:
> Hi Ingo,
>
> Great work on the -RT kernel! Here's a status report from my Athlon box
> w/ kernel -RT-2.6.11-rc3-V0.7.38-03, realtime-lsm-0.8.5, jack-0.99.48,
> alsa-1.0.8, and latencytest-0.5.5:
<snip>
> A couple BUGs are being logged (see below), but without any ill effect
> other than taking up space on my /var.
<snip>
> Network interface (via rhine) startup triggers these two BUGs:
>
> BUG: sleeping function called from invalid context ksoftirqd/0(2) at
> kernel/rt.c:1448
> in_atomic():1 [00000001], irqs_disabled():0
> [<c0103e77>] dump_stack+0x17/0x20 (12)
> [<c0119f89>] __might_sleep+0xd9/0xf0 (40)
> [<c0134816>] __spin_lock+0x36/0x50 (24)
> [<c0147914>] kmem_cache_alloc+0x34/0x120 (44)
> [<c01d3143>] sel_netif_lookup+0x63/0x150 (28)
> [<c01d32cd>] sel_netif_sids+0x2d/0xb0 (28)
> [<c01d01bc>] selinux_socket_sock_rcv_skb+0xac/0x230 (144)

I'm not sure I understand, as sel_netif_lookup passes GFP_ATOMIC to
kmalloc.

> [<c02fd248>] udp_queue_rcv_skb+0xb8/0x280 (28)
> [<c02fd8e2>] udp_rcv+0x192/0x3e0 (100)
> [<c02dc224>] ip_local_deliver+0x64/0x1c0 (32)
> [<c02dc595>] ip_rcv+0x215/0x3f0 (56)
> [<c02c201c>] netif_receive_skb+0x12c/0x160 (40)
> [<c02c20ce>] process_backlog+0x7e/0x110 (32)
> [<c02c21d2>] net_rx_action+0x72/0x130 (24)
> [<c0122428>] ___do_softirq+0x48/0xd0 (40)
> [<c012254b>] _do_softirq+0x1b/0x30 (8)
> [<c0122920>] ksoftirqd+0xa0/0xf0 (28)
> [<c01312fb>] kthread+0x8b/0xc0 (36)
> [<c01012f5>] kernel_thread_helper+0x5/0x10 (537116692)
> ---------------------------
> | preempt count: 00000002 ]
> | 2-level deep critical section nesting:
> ----------------------------------------
> .. [<c013dd3f>] .... __do_IRQ+0xef/0x180
> .....[<c0105306>] .. ( <= do_IRQ+0x56/0xa0)
> .. [<c0135240>] .... print_traces+0x10/0x40
> .....[<c0103e77>] .. ( <= dump_stack+0x17/0x20)

--
Stephen Smalley <sds@epoch.ncsc.mil>
National Security Agency