On 10.02.2019 14:05, Sander Eikelenboom wrote: > On 10/02/2019 12:44, Heiner Kallweit wrote: >> On 10.02.2019 10:16, Sander Eikelenboom wrote: >>> On 09/02/2019 12:50, Heiner Kallweit wrote: >>>> On 09.02.2019 11:07, Sander Eikelenboom wrote: >>>>> On 09/02/2019 10:59, Heiner Kallweit wrote: >>>>>> On 09.02.2019 10:34, Sander Eikelenboom wrote: >>>>>>> On 09/02/2019 10:02, Heiner Kallweit wrote: >>>>>>>> On 09.02.2019 00:09, Eric Dumazet wrote: >>>>>>>>> >>>>>>>>> >>>>>>>>> On 02/08/2019 01:50 PM, Heiner Kallweit wrote: >>>>>>>>>> On 08.02.2019 22:45, Sander Eikelenboom wrote: >>>>>>>>>>> On 08/02/2019 22:22, Heiner Kallweit wrote: >>>>>>>>>>>> On 08.02.2019 21:55, Sander Eikelenboom wrote: >>>>>>>>>>>>> On 08/02/2019 19:52, Heiner Kallweit wrote: >>>>>>>>>>>>>> On 08.02.2019 19:29, Sander Eikelenboom wrote: >>>>>>>>>>>>>>> L.S., >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> While testing a linux 5.0-rc5 kernel (with some patches on top >>>>>>>>>>>>>>> but they don't seem related) under Xen i the nasty splat below, >>>>>>>>>>>>>>> that I haven encountered with Linux 4.20.x. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Unfortunately I haven't got a clear reproducer for this and >>>>>>>>>>>>>>> bisecting could be nasty due to another (networking related) >>>>>>>>>>>>>>> kernel bug. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> If you need more info, want me to run a debug patch etc., >>>>>>>>>>>>>>> please feel free to ask. >>>>>>>>>>>>>>> >>>>>>>>>>>>>> Thanks for the report. However I see no change in the r8169 >>>>>>>>>>>>>> driver between >>>>>>>>>>>>>> 4.20 and 5.0 with regard to BQL code. Having said that the root >>>>>>>>>>>>>> cause could >>>>>>>>>>>>>> be somewhere else. Therefore I'm afraid a bisect will be needed. >>>>>>>>>>>>> >>>>>>>>>>>>> Hmm i did some diging and i think: >>>>>>>>>>>>> bd7153bd83b806bfcc2e79b7a6f43aa653d06ef3 r8169: remove unneeded >>>>>>>>>>>>> mmiowb barriers >>>>>>>>>>>>> 2e6eedb4813e34d8d84ac0eb3afb668966f3f356 r8169: make use of >>>>>>>>>>>>> xmit_more and __netdev_sent_queue >>>>>>>>>>>>> 620344c43edfa020bbadfd81a144ebe5181fc94f net: core: add >>>>>>>>>>>>> __netdev_sent_queue as variant of __netdev_tx_sent_queue >>>>>>>>>>>>> >>>>>>>>>>>> You're right. Thought this was added in 4.20 already. >>>>>>>>>>>> The BQL code pattern I copied from the mlx4 driver and so far I >>>>>>>>>>>> haven't heard about >>>>>>>>>>>> this issue from any user of physical hw. And due to the fact that >>>>>>>>>>>> a lot of mainboards >>>>>>>>>>>> have onboard Realtek network I have quite a few testers out there. >>>>>>>>>>>> Does the issue occur under specific circumstances like very high >>>>>>>>>>>> load? >>>>>>>>>>> >>>>>>>>>>> Yep, the box is already quite contented with the Xen VM's and if I >>>>>>>>>>> remember correctly it occurred while kernel compiling >>>>>>>>>>> on the host. >>>>>>>>>>> >>>>>>>>>>>> If indeed the xmit_more patch causes the issue, I think we have to >>>>>>>>>>>> involve Eric Dumazet >>>>>>>>>>>> as author of the underlying changes. >>>>>>>>>>> >>>>>>>>>>> It could also be the barriers weren't that unneeded as assumed. >>>>>>>>>> >>>>>>>>>> The barriers were removed after adding xmit_more handling. Therefore >>>>>>>>>> it would be good to >>>>>>>>>> test also with only >>>>>>>>>> bd7153bd83b806bfcc2e79b7a6f43aa653d06ef3 r8169: remove unneeded >>>>>>>>>> mmiowb barriers >>>>>>>>>> removed. >>>>>>>>>> >>>>>>>>>>> Since we are almost at RC6 i took the liberty to CC Eric now. >>>>>>>>>>> >>>>>>>>>> Sure, thanks. >>>>>>>>>> >>>>>>>>>>> BTW am i correct these patches are merely optimizations ? >>>>>>>>>> >>>>>>>>>> Yes >>>>>>>>>> >>>>>>>>>>> If so and concluding they revert cleanly, perhaps it should be >>>>>>>>>>> considered at this point in the RC's >>>>>>>>>>> to revert them for 5.0 and try again for 5.1 ? >>>>>>>>>>> >>>>>>>>>> Before removing both it would be good to test with only the >>>>>>>>>> barrier-removal removed. >>>>>>>>>> >>>>>>>>> >>>>>>>>> Commit 2e6eedb4813e34d8d84ac0eb3afb668966f3f356 r8169: make use of >>>>>>>>> xmit_more and __netdev_sent_queue >>>>>>>>> looks buggy to me, since the skb might have been freed already on >>>>>>>>> another cpu when you call >>>>>>>>> >>>>>>>>> You could try : >>>>>>>>> >>>>>>>>> diff --git a/drivers/net/ethernet/realtek/r8169.c >>>>>>>>> b/drivers/net/ethernet/realtek/r8169.c >>>>>>>>> index >>>>>>>>> 3624e67aef72c92ed6e908e2c99ac2d381210126..f907d484165d9fd775e81bf2bfb9aa4ddedb1c93 >>>>>>>>> 100644 >>>>>>>>> --- a/drivers/net/ethernet/realtek/r8169.c >>>>>>>>> +++ b/drivers/net/ethernet/realtek/r8169.c >>>>>>>>> @@ -6070,6 +6070,7 @@ static netdev_tx_t rtl8169_start_xmit(struct >>>>>>>>> sk_buff *skb, >>>>>>>>> dma_addr_t mapping; >>>>>>>>> u32 opts[2], len; >>>>>>>>> bool stop_queue; >>>>>>>>> + bool door_bell; >>>>>>>>> int frags; >>>>>>>>> >>>>>>>>> if (unlikely(!rtl_tx_slots_avail(tp, >>>>>>>>> skb_shinfo(skb)->nr_frags))) { >>>>>>>>> @@ -6116,6 +6117,8 @@ static netdev_tx_t rtl8169_start_xmit(struct >>>>>>>>> sk_buff *skb, >>>>>>>>> /* Force memory writes to complete before releasing >>>>>>>>> descriptor */ >>>>>>>>> dma_wmb(); >>>>>>>>> >>>>>>>>> + door_bell = __netdev_sent_queue(dev, skb->len, >>>>>>>>> skb->xmit_more); >>>>>>>>> + >>>>>>>>> txd->opts1 = rtl8169_get_txd_opts1(opts[0], len, entry); >>>>>>>>> >>>>>>>>> /* Force all memory writes to complete before notifying >>>>>>>>> device */ >>>>>>>>> @@ -6127,7 +6130,7 @@ static netdev_tx_t rtl8169_start_xmit(struct >>>>>>>>> sk_buff *skb, >>>>>>>>> if (unlikely(stop_queue)) >>>>>>>>> netif_stop_queue(dev); >>>>>>>>> >>>>>>>>> - if (__netdev_sent_queue(dev, skb->len, skb->xmit_more)) { >>>>>>>>> + if (door_bell) { >>>>>>>>> RTL_W8(tp, TxPoll, NPQ); >>>>>>>>> mmiowb(); >>>>>>>>> } >>>>>>>>> >>>>>>>> Thanks a lot for checking and for the proposed fix. >>>>>>>> Sander, can you try with this patch on top of 5.0-rc5 w/o removing two >>>>>>>> two commits? >>>>>>> >>>>>>> I have done that already during the night .. the results: >>>>>>> - I can confirm 2e6eedb4813e34d8d84ac0eb3afb668966f3f356 is the first >>>>>>> commit which causes hitting the BUG_ON in lib/dynamic_queue_limits.c. >>>>>>> (in other word, with only reverting >>>>>>> bd7153bd83b806bfcc2e79b7a6f43aa653d06ef3 it still blows up). >>>>>>> >>>>>>> - The Eric's patch only applies cleanly with >>>>>>> bd7153bd83b806bfcc2e79b7a6f43aa653d06ef3 reverted, so that's what I >>>>>>> tested. >>>>>>> The patch seems to prevent hitting the BUG_ON in >>>>>>> lib/dynamic_queue_limits.c, it has run this night and I gave done a few >>>>>>> kernel compiles >>>>>>> this morning. How ever during these kernel compiles i'm getting a >>>>>>> transmit queue timeout which i haven't seen with 4.20.x, although i >>>>>>> regularly >>>>>>> compile kernels in the same way as I do now. The only thing I can't >>>>>>> say if that is due to this change, or if it's again something else. >>>>>>> Which makes me somewhat inclined to go testing the complete revert >>>>>>> some more and see if I can trigger the queue timeout on that or not. >>>>>>> >>>>>>> If I can, it is a separate issue. >>>>>>> If I can't it seems even with a patch it still seems as a regression >>>>>>> in comparison with 4.20.x, for which >>>>>>> a revert would be the right thing to do (since as you indicated these >>>>>>> are merely optimizations), >>>>>>> which would give us more time for 5.1 to try to solve things on top >>>>>>> of the 5.0-release-to-be. >>>>>>> (especially since I seem to still have other issues which need to be >>>>>>> sorted out and time is limited) >>>>>>> >>>>>>> The timeout in question: >>>>>>> [28336.869479] NETDEV WATCHDOG: eth1 (r8169): transmit queue 0 >>>>>>> timed out >>>>>>> [28336.881498] WARNING: CPU: 0 PID: 6925 at >>>>>>> net/sched/sch_generic.c:461 dev_watchdog+0x20b/0x210 >>>>>>> [28336.893358] Modules linked in: >>>>>>> [28336.904106] CPU: 0 PID: 6925 Comm: cc1 Tainted: G D >>>>>>> 5.0.0-rc5-20190208-thp-net-florian-rtl8169-eric-doflr+ #1 >>>>>>> [28336.917385] Hardware name: MSI MS-7640/890FXA-GD70 (MS-7640) >>>>>>> , BIOS V1.8B1 09/13/2010 >>>>>>> [28336.928988] RIP: e030:dev_watchdog+0x20b/0x210 >>>>>>> [28336.940623] Code: 00 49 63 4e e0 eb 90 4c 89 e7 c6 05 ad d8 >>>>>>> f1 00 01 e8 a9 32 fd ff 89 d9 48 89 c2 4c 89 e6 48 c7 c7 50 59 89 82 e8 >>>>>>> e5 92 4d ff <0f> 0b eb c0 90 48 c7 47 08 00 00 00 00 48 c7 07 00 00 00 >>>>>>> 00 0f b7 >>>>>>> [28336.965265] RSP: e02b:ffff88807d403ea0 EFLAGS: 00010286 >>>>>>> [28336.977465] RAX: 0000000000000000 RBX: 0000000000000000 RCX: >>>>>>> ffffffff82a69db8 >>>>>>> [28336.991265] RDX: 0000000000000001 RSI: 0000000000000001 RDI: >>>>>>> 0000000000000200 >>>>>>> [28337.008865] RBP: ffff88807936e41c R08: 0000000000000000 R09: >>>>>>> 0000000000000819 >>>>>>> [28337.022250] R10: 0000000000000202 R11: ffffffff8247ca80 R12: >>>>>>> ffff88807936e000 >>>>>>> [28337.035204] R13: 0000000000000000 R14: ffff88807936e440 R15: >>>>>>> 0000000000000001 >>>>>>> [28337.049832] FS: 00007f53e9bf3840(0000) >>>>>>> GS:ffff88807d400000(0000) knlGS:0000000000000000 >>>>>>> [28337.062524] CS: e030 DS: 0000 ES: 0000 CR0: 0000000080050033 >>>>>>> [28337.075086] CR2: 00007f53e60c4000 CR3: 000000001a0be000 CR4: >>>>>>> 0000000000000660 >>>>>>> [28337.090052] Call Trace: >>>>>>> [28337.103615] <IRQ> >>>>>>> [28337.116587] ? qdisc_destroy+0x120/0x120 >>>>>>> [28337.128905] call_timer_fn+0x19/0x90 >>>>>>> [28337.141892] expire_timers+0x8b/0xa0 >>>>>>> [28337.153354] run_timer_softirq+0x7e/0x160 >>>>>>> [28337.165931] ? handle_irq_event_percpu+0x4c/0x70 >>>>>>> [28337.176548] ? handle_percpu_irq+0x32/0x50 >>>>>>> [28337.186734] __do_softirq+0xed/0x229 >>>>>>> [28337.196404] ? hypervisor_callback+0xa/0x20 >>>>>>> [28337.207822] irq_exit+0xb7/0xc0 >>>>>>> [28337.218978] xen_evtchn_do_upcall+0x27/0x40 >>>>>>> [28337.230763] xen_do_hypervisor_callback+0x29/0x40 >>>>>>> [28337.241261] </IRQ> >>>>>>> [28337.253283] RIP: e033:0xff7e62 >>>>>>> [28337.264899] Code: 35 43 0f c7 00 4c 89 ef e8 8b 6d 67 ff 0f >>>>>>> 1f 00 44 89 e0 44 89 e2 c1 e8 06 83 e2 3f 48 8b 0c c5 40 8d c6 01 48 0f >>>>>>> a3 d1 72 0e <48> 8b 04 c5 50 8d c6 01 48 0f a3 d0 73 0b 44 89 e6 4c 89 >>>>>>> ef e8 b5 >>>>>>> [28337.288677] RSP: e02b:00007fff0fc6a340 EFLAGS: 00000202 >>>>>>> [28337.299234] RAX: 0000000000000000 RBX: 00007f53e60c3580 RCX: >>>>>>> 0000000000000000 >>>>>>> [28337.309577] RDX: 0000000000000034 RSI: 0000000001e71a98 RDI: >>>>>>> 00007fff0fc6a538 >>>>>>> [28337.320724] RBP: 00007fff0fc6a4b0 R08: 0000000000000000 R09: >>>>>>> 0000000000000000 >>>>>>> [28337.331829] R10: 0000000000000001 R11: 00000000020cb3d0 R12: >>>>>>> 0000000000000034 >>>>>>> [28337.343900] R13: 00007fff0fc6a538 R14: 0000000000000000 R15: >>>>>>> 0000000000000001 >>>>>>> [28337.353977] ---[ end trace 6ff49f09286816b7 ]--- >>>>>>> >>>>>> Thanks for your efforts. As usual this tx timeout trace says basically >>>>>> nothing except >>>>>> "timeout" and root cause could be anything. Earlier you reported a >>>>>> memory allocation error, >>>>>> did that occur again? >>>>>> If we decide to revert, I'd leave removal of the memory barriers in (as >>>>>> it doesn't seem to >>>>>> contribute to the issue) and just submit a patch to effectively revert >>>>>> 2e6eedb4813e34d8d84ac0eb3afb668966f3f356. >>>>> >>>>> I can't say if that is correct, because i haven't tested that. >>>>> >>>>> Another thing I could test is: >>>>> - putting all the r8169 patches (and prerequisites) that went into 5.0 >>>>> up to bd7153bd83b806bfcc2e79b7a6f43aa653d06ef3, onto 4.20.7 and see >>>>> what that does. >>>>> If that would be feasible (not too many needed prerequisites out of >>>>> r8169) and if >>>>> you could spare me some time and prep such a branch somewhere so i can >>>>> pull and compile that, >>>>> that would be great. >>>>> >>>> >>>> Unfortunately there's quite a number of changes. Regarding >>>> __netdev_tx_sent_queue() >>>> and watchdog timeout I found the following comment in >>>> drivers/net/ethernet/sfc/tx.c, >>>> efx_enqueue_skb(): >>>> >>>> if (__netdev_tx_sent_queue(tx_queue->core_txq, skb_len, xmit_more)) { >>>> struct efx_tx_queue *txq2 = efx_tx_queue_partner(tx_queue); >>>> >>>> /* There could be packets left on the partner queue if those >>>> * SKBs had skb->xmit_more set. If we do not push those they >>>> * could be left for a long time and cause a netdev watchdog. >>>> */ >>>> if (txq2->xmit_more_available) >>>> efx_nic_push_buffers(txq2); >>>> >>>> But I'm not sure whether the situation in r8169 is comparable. The >>>> following patch >>>> implements what I mentioned earlier: It leaves all other 5.0 changes in >>>> place and >>>> effectively reverts 2e6eedb4813e34d8d84ac0eb3afb668966f3f356. Would be >>>> great if >>>> you could give it a try. >>> >>> Hi Heiner, >>> >>> It took some time to respond, because I had another issue with 5.0 which >>> intervened with proper testing, >>> but fortunately I could pinpoint without doing a full bisect and revert >>> that commit for further testing. >>> >>> So there is still time left and I could do a more proper run with your >>> patch below. >>> Unfortunately i still get a splat (see below) with this, although i'm not >>> sure it is related, >>> just that I can't tell. >>> >> I checked further and there's a handful of network drivers using >> __napi_alloc_skb() with __GFP_NOWARN, >> maybe to avoid such splats. Did the splat impact functionality? When >> checking the code in r8169 the >> affected packet would just be dropped. > > It doesn't permanently or noticeably impact functionality, and indeed seems > to drop packets: > > eth1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 > inet 172.16.1.1 netmask 255.255.0.0 broadcast 172.16.255.255 > ether 40:61:86:f4:67:d8 txqueuelen 1000 (Ethernet) > RX packets 11563913 bytes 16724445852 (15.5 GiB) > RX errors 0 dropped 6 overruns 0 frame 0 > TX packets 4301515 bytes 1210966808 (1.1 GiB) > TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 > > Reverting 5317d5c6d47e ("r8169: use napi_consume_skb where possible") doesn't > suffice still gives the page allocation failure. > > I think at this point in time we should at least get the > reverts into 5.0 (probably to late for rc-6 since DaveM's pull request is > already in) for: > bd7153bd83b806bfcc2e79b7a6f43aa653d06ef3 r8169: remove unneeded mmiowb > barriers > 2e6eedb4813e34d8d84ac0eb3afb668966f3f356 r8169: make use of xmit_more and > __netdev_sent_queue > OK, I just sent the reverts for both patches.
Heiner > Commit 2e6eedb4813e34d8d84ac0eb3afb668966f3f356 is the one which caused the > BUG_ON() to be hit. > > While we could use your patch to revert only > 2e6eedb4813e34d8d84ac0eb3afb668966f3f356 and leave > bd7153bd83b806bfcc2e79b7a6f43aa653d06ef3 in: > - I haven't been able to test it properly. > - It's dealing with barriers, which can be tedious and give subtle > breakage. > - I don't see any compelling argument to keep it in (it's no fix). > - It's RC-6 time ... > > So we then we can focus on the page allocation issue and hopefully find some > stable > baseline before 5.0-final is cut. While I appreciate having a forward looking > approach, > I think we are at the point in time, were we should revert when in doubt > (and it doesn't clearly fix an other issue). > > After establishing a stable baseline again, we can start incrementally > re-applying and test stuff. > > -- > Sander > > > >>> Perhaps Linus as Oops-decoding-guru has an idea ? >>> >>> -- >>> Sander >>> >>> [39041.689007] dpkg-deb: page allocation failure: order:0, >>> mode:0x480020(GFP_ATOMIC), nodemask=(null),cpuset=/,mems_allowed=0 >>> [39041.689016] CPU: 4 PID: 14078 Comm: dpkg-deb Not tainted >>> 5.0.0-rc5-20190209-kallweit+ #1 >>> [39041.689017] Hardware name: MSI MS-7640/890FXA-GD70 (MS-7640) , BIOS >>> V1.8B1 09/13/2010 >>> [39041.689018] Call Trace: >>> [39041.689022] <IRQ> >>> [39041.689030] dump_stack+0x5c/0x7b >>> [39041.689033] warn_alloc+0x103/0x190 >>> [39041.689036] __alloc_pages_nodemask+0xe3d/0xe80 >>> [39041.689039] ? ip_rcv+0x48/0xc0 >>> [39041.689040] ? ip_rcv_finish_core.isra.0+0x360/0x360 >>> [39041.689042] page_frag_alloc+0x117/0x150 >>> [39041.689044] __napi_alloc_skb+0x83/0xd0 >>> [39041.689048] rtl8169_poll+0x210/0x640 >>> [39041.689051] net_rx_action+0x23d/0x370 >>> [39041.689054] __do_softirq+0xed/0x229 >>> [39041.689058] irq_exit+0xb7/0xc0 >>> [39041.689061] xen_evtchn_do_upcall+0x27/0x40 >>> [39041.689063] xen_do_hypervisor_callback+0x29/0x40 >>> [39041.689064] </IRQ> >>> [39041.689066] RIP: e030:_atomic_dec_and_lock+0x2/0x40 >>> [39041.689068] Code: ff 39 05 c5 c1 c9 00 89 c7 89 c6 76 0f 83 eb 01 83 fb >>> ff 75 d9 5b 89 f8 5d 41 5c c3 0f 0b 90 90 90 90 90 90 90 90 90 90 8b 07 >>> <83> f8 01 74 0c 8d 50 ff f0 0f b1 17 75 f2 31 c0 c3 55 53 48 89 fb >>> [39041.689069] RSP: e02b:ffffc9000705b990 EFLAGS: 00000246 >>> [39041.689071] RAX: 0000000000000001 RBX: ffff888017082640 RCX: >>> 0000000000000000 >>> [39041.689071] RDX: 0000000000000000 RSI: ffff8880170826c0 RDI: >>> ffff888017082788 >>> [39041.689072] RBP: ffff8880170826c0 R08: ffffc9000705bb00 R09: >>> ffffc9000705bb00 >>> [39041.689073] R10: ffffc9000705bb58 R11: ffff88807fc17000 R12: >>> ffff888017082788 >>> [39041.689073] R13: ffff88806cc8cf58 R14: ffff888017082640 R15: >>> ffff888009990240 >>> [39041.689077] iput+0x63/0x1a0 >>> [39041.689079] __dentry_kill+0xc5/0x170 >>> [39041.689080] shrink_dentry_list+0x93/0x1c0 >>> [39041.689082] prune_dcache_sb+0x4d/0x70 >>> [39041.689084] super_cache_scan+0x104/0x190 >>> [39041.689087] do_shrink_slab+0x12c/0x1e0 >>> [39041.689089] shrink_slab+0xdf/0x2b0 >>> [39041.689091] shrink_node+0x158/0x470 >>> [39041.689093] do_try_to_free_pages+0xd1/0x380 >>> [39041.689095] try_to_free_pages+0xb2/0xe0 >>> [39041.689097] __alloc_pages_nodemask+0x603/0xe80 >>> [39041.689099] ? __pagevec_lru_add_fn+0x1b1/0x290 >>> [39041.689102] alloc_pages_vma+0x7b/0x1c0 >>> [39041.689106] __handle_mm_fault+0xdb3/0x1060 >>> [39041.689109] ? xen_mc_flush+0xc0/0x190 >>> [39041.689110] handle_mm_fault+0xf8/0x200 >>> [39041.689113] __do_page_fault+0x231/0x4a0 >>> [39041.689115] ? page_fault+0x8/0x30 >>> [39041.689116] page_fault+0x1e/0x30 >>> [39041.689118] RIP: e033:0x7fb9851d012e >>> [39041.689119] Code: 29 c2 48 3b 15 7b a3 31 00 0f 87 af 00 00 00 0f 10 01 >>> 0f 10 49 f0 0f 10 51 e0 0f 10 59 d0 48 83 e9 40 48 83 ea 40 41 0f 29 01 >>> <41> 0f 29 49 f0 41 0f 29 51 e0 41 0f 29 59 d0 49 83 e9 40 48 83 fa >>> [39041.689119] RSP: e02b:00007fb958b36d38 EFLAGS: 00010202 >>> [39041.689120] RAX: 00007fb97a617f0e RBX: 000000000000f004 RCX: >>> 00007fb948008be3 >>> [39041.689121] RDX: 00000000000080c2 RSI: 00007fb948000b31 RDI: >>> 00007fb97a617f0e >>> [39041.689122] RBP: 00000000000ff062 R08: 0000000000000002 R09: >>> 00007fb97a620000 >>> [39041.689123] R10: 0000000000000004 R11: 00007fb97a626f02 R12: >>> 000000000000f005 >>> [39041.689123] R13: 00007fb948000b28 R14: 0000562d76b63710 R15: >>> 0000000000000003 >>> [39041.689125] Mem-Info: >>> [39041.689130] active_anon:78775 inactive_anon:49211 isolated_anon:0 >>> active_file:106409 inactive_file:107531 isolated_file:0 >>> unevictable:552 dirty:175 writeback:0 unstable:0 >>> slab_reclaimable:13739 slab_unreclaimable:16454 >>> mapped:1605 shmem:23 pagetables:2900 bounce:0 >>> free:3681 free_pcp:935 free_cma:0 >>> [39041.689132] Node 0 active_anon:315100kB inactive_anon:196844kB >>> active_file:425636kB inactive_file:430124kB unevictable:2208kB >>> isolated(anon):0kB isolated(file):0kB mapped:6420kB dirty:700kB >>> writeback:0kB shmem:92kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 0kB >>> writeback_tmp:0kB unstable:0kB all_unreclaimable? no >>> [39041.689133] Node 0 DMA free:7480kB min:44kB low:56kB high:68kB >>> active_anon:0kB inactive_anon:7832kB active_file:472kB inactive_file:4kB >>> unevictable:0kB writepending:0kB present:15956kB managed:15872kB >>> mlocked:0kB kernel_stack:0kB pagetables:12kB bounce:0kB free_pcp:0kB >>> local_pcp:0kB free_cma:0kB >>> [39041.689136] lowmem_reserve[]: 0 1865 1865 1865 >>> [39041.689138] Node 0 DMA32 free:7244kB min:19472kB low:21380kB >>> high:23288kB active_anon:315360kB inactive_anon:188144kB >>> active_file:425164kB inactive_file:430120kB unevictable:2208kB >>> writepending:700kB present:2080768kB managed:1674968kB mlocked:2208kB >>> kernel_stack:9632kB pagetables:11588kB bounce:0kB free_pcp:3740kB >>> local_pcp:528kB free_cma:0kB >>> [39041.689140] lowmem_reserve[]: 0 0 0 0 >>> [39041.689142] Node 0 DMA: 6*4kB (UME) 6*8kB (UE) 7*16kB (UME) 6*32kB (ME) >>> 5*64kB (UME) 3*128kB (UE) 5*256kB (UME) 2*512kB (ME) 2*1024kB (UE) 1*2048kB >>> (M) 0*4096kB = 7480kB >>> [39041.689148] Node 0 DMA32: 69*4kB (U) 315*8kB (UE) 138*16kB (UE) 70*32kB >>> (UE) 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 7244kB >>> [39041.689153] 214701 total pagecache pages >>> [39041.689155] 273 pages in swap cache >>> [39041.689156] Swap cache stats: add 100978, delete 100706, find 1158/1257 >>> [39041.689156] Free swap = 3790588kB >>> [39041.689157] Total swap = 4194300kB >>> [39041.689157] 524181 pages RAM >>> [39041.689158] 0 pages HighMem/MovableOnly >>> [39041.689158] 101471 pages reserved >>> [39041.689159] 0 pages cma reserved >>> >>> >>> >>> >>> >>>> diff --git a/drivers/net/ethernet/realtek/r8169.c >>>> b/drivers/net/ethernet/realtek/r8169.c >>>> index e8a112149..3cca2ffb2 100644 >>>> --- a/drivers/net/ethernet/realtek/r8169.c >>>> +++ b/drivers/net/ethernet/realtek/r8169.c >>>> @@ -6192,7 +6192,6 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff >>>> *skb, >>>> struct device *d = tp_to_dev(tp); >>>> dma_addr_t mapping; >>>> u32 opts[2], len; >>>> - bool stop_queue; >>>> int frags; >>>> >>>> if (unlikely(!rtl_tx_slots_avail(tp, skb_shinfo(skb)->nr_frags))) { >>>> @@ -6234,6 +6233,8 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff >>>> *skb, >>>> >>>> txd->opts2 = cpu_to_le32(opts[1]); >>>> >>>> + netdev_sent_queue(dev, skb->len); >>>> + >>>> skb_tx_timestamp(skb); >>>> >>>> /* Force memory writes to complete before releasing descriptor */ >>>> @@ -6246,14 +6247,14 @@ static netdev_tx_t rtl8169_start_xmit(struct >>>> sk_buff *skb, >>>> >>>> tp->cur_tx += frags + 1; >>>> >>>> - stop_queue = !rtl_tx_slots_avail(tp, MAX_SKB_FRAGS); >>>> - if (unlikely(stop_queue)) >>>> - netif_stop_queue(dev); >>>> - >>>> - if (__netdev_sent_queue(dev, skb->len, skb->xmit_more)) >>>> - RTL_W8(tp, TxPoll, NPQ); >>>> + RTL_W8(tp, TxPoll, NPQ); >>>> >>>> - if (unlikely(stop_queue)) { >>>> + if (!rtl_tx_slots_avail(tp, MAX_SKB_FRAGS)) { >>>> + /* Avoid wrongly optimistic queue wake-up: rtl_tx thread must >>>> + * not miss a ring update when it notices a stopped queue. >>>> + */ >>>> + smp_wmb(); >>>> + netif_stop_queue(dev); >>>> /* Sync with rtl_tx: >>>> * - publish queue status and cur_tx ring index (write barrier) >>>> * - refresh dirty_tx ring index (read barrier). >>>> >>> >>> >> > >