On 25/02/2019 21:03, Trond Myklebust wrote: > On Mon, 2019-02-25 at 20:25 +0000, Jon Hunter wrote: >> Hi Trond, >> >> Starting in next-20190222 I have observed a regression with NFS >> causing >> some of our boards to fail to boot. Bisect points to your commit ... >> >> commit 0ffe86f48026b7f34db22d1004bc9992f0db8b33 >> Author: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> >> Date: Wed Jan 30 14:51:26 2019 -0500 >> >> SUNRPC: Use poll() to fix up the socket requeue races >> >> >> After reverting this on top of -next I no longer see the problem. I >> have >> not had chance to look any closer, but wanted to see if you had any >> ideas what might be the problem. >> >> Cheers >> Jon > > What kind of boot is this? UDP or TCP? nfsroot? NFSv3 or NFSv4? This is nfsroot. I don't specify any particular NFS version from the kernel cmdline, but this is seen with ARM kernel configs tegra_defconfig and multi_v7_defconfig. Looking at the logs I am seeing the following crash which appears to point to UDP ... [ 8.032956] Unable to handle kernel NULL pointer dereference at virtual address 00000024 [ 8.041137] pgd = (ptrval) [ 8.043858] [00000024] *pgd=00000000 [ 8.047437] Internal error: Oops: 5 [#1] SMP ARM [ 8.052049] Modules linked in: [ 8.055104] CPU: 1 PID: 100 Comm: kworker/u9:2 Not tainted 5.0.0-rc7-next-20190222-g94a4752 #1 [ 8.063699] Hardware name: NVIDIA Tegra SoC (Flattened Device Tree) [ 8.069960] Workqueue: xprtiod xs_udp_data_receive_workfn [ 8.075353] PC is at udp_poll+0x30/0x64 [ 8.079178] LR is at udp_poll+0x10/0x64 [ 8.083006] pc : [<c0d3be08>] lr : [<c0d3bde8>] psr: 20000113 [ 8.089257] sp : e8963ea8 ip : 00000000 fp : 00001064 [ 8.094471] r10: 00000000 r9 : e8963ef4 r8 : e8963efc [ 8.099687] r7 : e940db34 r6 : 00000000 r5 : e9d1c540 r4 : 00000345 [ 8.106203] r3 : c0d3bdd8 r2 : e8908cc0 r1 : e8908cc0 r0 : e89089c0 [ 8.112718] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none [ 8.119843] Control: 10c5387d Table: 8020406a DAC: 00000051 [ 8.125579] Process kworker/u9:2 (pid: 100, stack limit = 0x(ptrval)) [ 8.132008] Stack: (0xe8963ea8 to 0xe8964000) [ 8.136352] 3ea0: e940d800 e940db04 e89089c0 c0dcac04 fffffff5 00000000 [ 8.144515] 3ec0: e88f4400 c0dcae80 e8963efc e8963ef4 e940da58 e940d800 c187c680 e8941b58 [ 8.152681] 3ee0: 000010f0 e940da50 e940db44 00000000 e8963f44 fffffff5 00000000 00000000 [ 8.160838] 3f00: e894247c ea203180 e940db34 ea3f5c00 e940db38 ea35e500 00000000 00000000 [ 8.169001] 3f20: c188ef50 c035f21c ea3f5c00 ea3f5c00 e8962018 ea203180 ea3f5c00 ea3f5c18 [ 8.177164] 3f40: e8962018 c188e91c ea203194 c1703d00 00000088 c035f548 e890d05c e8962000 [ 8.185327] 3f60: ea200480 c1703d00 e890d05c e890d040 ea200480 00000000 e890d05c ea203180 [ 8.193492] 3f80: c035f508 ea433ebc 00000000 c0364810 ea200480 c03646ec 00000000 00000000 [ 8.201657] 3fa0: 00000000 00000000 00000000 c03010e8 00000000 00000000 00000000 00000000 [ 8.209815] 3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 8.217979] 3fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000 [ 8.226154] [<c0d3be08>] (udp_poll) from [<c0dcac04>] (xs_poll_check_readable+0x30/0x70) [ 8.234241] [<c0dcac04>] (xs_poll_check_readable) from [<c0dcae80>] (xs_udp_data_receive_workfn+0x23c/0x2a0) [ 8.244062] [<c0dcae80>] (xs_udp_data_receive_workfn) from [<c035f21c>] (process_one_work+0x164/0x450) [ 8.253359] [<c035f21c>] (process_one_work) from [<c035f548>] (worker_thread+0x40/0x524) [ 8.261444] [<c035f548>] (worker_thread) from [<c0364810>] (kthread+0x124/0x154) [ 8.268834] [<c0364810>] (kthread) from [<c03010e8>] (ret_from_fork+0x14/0x2c) [ 8.276044] Exception stack(0xe8963fb0 to 0xe8963ff8) [ 8.281084] 3fa0: 00000000 00000000 00000000 00000000 [ 8.289248] 3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 8.297411] 3fe0: 00000000 00000000 00000000 00000000 00000013 00000000 [ 8.304017] Code: e1510002 13844041 e3140040 0a000005 (e5962024) [ 8.310129] ---[ end trace 52d5b8bca1dce72c ]--- [ 19.321470] nfs: server 192.168.99.1 not responding, still trying [ 55.001474] nfs: server 192.168.99.1 not responding, still trying Cheers Jon -- nvpublic