On Fri, 2017-05-19 at 14:47 -0400, Akshay Narayan wrote: > > I don't want to defend the use of yield() but it looks like there is other > > problem. > > I believe this use of yield() should be replaced with cond_resched() > even if it turns out there is an unrelated problem. > > > Does this module call netlink_broadcast() with __GFP_DIRECT_RECLAIM > > in IRQ context? If so you should adjust the gfp flags. > > The module only calls netlink_broadcast() from a pluggable TCP > function; from my understanding this is not in the IRQ context. Full > trace, perhaps more clear, attached below. > > May 19 14:30:44 ccp kernel: [ 178.885546] BUG: scheduling while > atomic: mm-link/3105/0x00000200 > May 19 14:30:44 ccp kernel: [ 178.885552] Modules linked in: > ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack_ipv4 > nf_defrag_ipv4 nf_nat_ipv4 nf_nat libcrc32c xt_connmark nf_conntrack > ccp(OE) crct10dif_pclmul crc32_pclmul > ghash_clmulni_intel snd_intel8x0 pcbc snd_ac97_codec joydev ac97_bus > snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi aesni_intel > snd_seq aes_x86_64 crypto_simd snd_seq_device snd_timer snd input_leds > i2c_piix4 glue_helper cryptd so > undcore mac_hid serio_raw vboxvideo ttm drm_kms_helper drm fb_sys_fops > syscopyarea sysfillrect sysimgblt vboxguest intel_rapl_perf parport_pc > ppdev lp parport ip_tables x_tables autofs4 hid_generic usbhid hid > e1000 ahci libahci psmouse > fjes pata_acpi video > May 19 14:30:44 ccp kernel: [ 178.885665] CPU: 0 PID: 3105 Comm: > mm-link Tainted: G W OE 4.10.0-21-generic #23-Ubuntu > May 19 14:30:44 ccp kernel: [ 178.885666] Hardware name: innotek GmbH > VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 > May 19 14:30:44 ccp kernel: [ 178.885667] Call Trace: > May 19 14:30:44 ccp kernel: [ 178.885674] dump_stack+0x63/0x81 > May 19 14:30:44 ccp kernel: [ 178.885678] __schedule_bug+0x54/0x70 > May 19 14:30:44 ccp kernel: [ 178.885682] __schedule+0x536/0x6f0 > May 19 14:30:44 ccp kernel: [ 178.885685] schedule+0x36/0x80 > May 19 14:30:44 ccp kernel: [ 178.885687] sys_sched_yield+0x4f/0x60 > May 19 14:30:44 ccp kernel: [ 178.885688] yield+0x33/0x40 > May 19 14:30:44 ccp kernel: [ 178.885691] > netlink_broadcast_filtered+0x29b/0x3c0 > May 19 14:30:44 ccp kernel: [ 178.885692] netlink_broadcast+0x1d/0x20 > May 19 14:30:44 ccp kernel: [ 178.885697] nl_sendmsg+0xb8/0x664 [ccp] > May 19 14:30:44 ccp kernel: [ 178.885699] nl_send_ack_notif+0x7d/0x90 [ccp] > May 19 14:30:44 ccp kernel: [ 178.885702] tcp_ccp_cong_avoid+0x69/0x70 [ccp] > May 19 14:30:44 ccp kernel: [ 178.885704] tcp_ack+0x980/0xa60 > May 19 14:30:44 ccp kernel: [ 178.885708] tcp_rcv_state_process+0x2be/0xda0 > May 19 14:30:44 ccp kernel: [ 178.885712] ? security_sock_rcv_skb+0x3b/0x50 > May 19 14:30:44 ccp kernel: [ 178.885715] ? sk_filter_trim_cap+0x3b/0x270
No idea what ccp is, it is not in upstream kernel, and it looks buggy. Please do not send patches that are not needed in upstream kernel.
