On 5/14/19 7:54 AM, Pankaj Gupta wrote:> + if (!list_empty(&vpmem->req_list)) { > + req_buf = list_first_entry(&vpmem->req_list, > + struct virtio_pmem_request, list); > + req_buf->wq_buf_avail = true; > + wake_up(&req_buf->wq_buf); > + list_del(&req_buf->list);Yes, this change is the right one, thank you!> + /* > + * If virtqueue_add_sgs returns -ENOSPC then req_vq virtual > + * queue does not have free descriptor. We add the request > + * to req_list and wait for host_ack to wake us up when free > + * slots are available. > + */ > + while ((err = virtqueue_add_sgs(vpmem->req_vq, sgs, 1, 1, req, > + GFP_ATOMIC)) == -ENOSPC) { > + > + dev_err(&vdev->dev, "failed to send command to virtio pmem" \ > + "device, no free slots in the virtqueue\n"); > + req->wq_buf_avail = false; > + list_add_tail(&req->list, &vpmem->req_list); > + spin_unlock_irqrestore(&vpmem->pmem_lock, flags); > + > + /* A host response results in "host_ack" getting called */ > + wait_event(req->wq_buf, req->wq_buf_avail); > + spin_lock_irqsave(&vpmem->pmem_lock, flags); > + } > + err1 = virtqueue_kick(vpmem->req_vq); > + spin_unlock_irqrestore(&vpmem->pmem_lock, flags); > + > + /* > + * virtqueue_add_sgs failed with error different than -ENOSPC, we can't > + * do anything about that. > + */ > + if (err || !err1) { > + dev_info(&vdev->dev, "failed to send command to virtio pmem device\n"); > + err = -EIO; > + } else { > + /* A host repsonse results in "host_ack" getting called */ > + wait_event(req->host_acked, req->done); > + err = req->ret; > +I confirm that the failures I was facing with the `-ENOSPC` error path are not present in v9.Best, Jakub Staron
Pankaj Gupta
2019-May-17 05:35 UTC
[Qemu-devel] [PATCH v9 2/7] virtio-pmem: Add virtio pmem driver
Hi Jakub,> > On 5/14/19 7:54 AM, Pankaj Gupta wrote: > > + if (!list_empty(&vpmem->req_list)) { > > + req_buf = list_first_entry(&vpmem->req_list, > > + struct virtio_pmem_request, list); > > + req_buf->wq_buf_avail = true; > > + wake_up(&req_buf->wq_buf); > > + list_del(&req_buf->list); > Yes, this change is the right one, thank you!Thank you for the confirmation.> > > + /* > > + * If virtqueue_add_sgs returns -ENOSPC then req_vq virtual > > + * queue does not have free descriptor. We add the request > > + * to req_list and wait for host_ack to wake us up when free > > + * slots are available. > > + */ > > + while ((err = virtqueue_add_sgs(vpmem->req_vq, sgs, 1, 1, req, > > + GFP_ATOMIC)) == -ENOSPC) { > > + > > + dev_err(&vdev->dev, "failed to send command to virtio pmem" \ > > + "device, no free slots in the virtqueue\n"); > > + req->wq_buf_avail = false; > > + list_add_tail(&req->list, &vpmem->req_list); > > + spin_unlock_irqrestore(&vpmem->pmem_lock, flags); > > + > > + /* A host response results in "host_ack" getting called */ > > + wait_event(req->wq_buf, req->wq_buf_avail); > > + spin_lock_irqsave(&vpmem->pmem_lock, flags); > > + } > > + err1 = virtqueue_kick(vpmem->req_vq); > > + spin_unlock_irqrestore(&vpmem->pmem_lock, flags); > > + > > + /* > > + * virtqueue_add_sgs failed with error different than -ENOSPC, we can't > > + * do anything about that. > > + */ > > + if (err || !err1) { > > + dev_info(&vdev->dev, "failed to send command to virtio pmem device\n"); > > + err = -EIO; > > + } else { > > + /* A host repsonse results in "host_ack" getting called */ > > + wait_event(req->host_acked, req->done); > > + err = req->ret; > > +I confirm that the failures I was facing with the `-ENOSPC` error path are > > not present in v9.Can I take it your reviewed/acked-by? or tested-by tag? for the virtio patch :) Thank you, Pankaj> > Best, > Jakub Staron > >
Jakub Staroń
2019-May-18 01:10 UTC
[Qemu-devel] [PATCH v9 2/7] virtio-pmem: Add virtio pmem driver
On 5/16/19 10:35 PM, Pankaj Gupta wrote:> Can I take it your reviewed/acked-by? or tested-by tag? for the virtio patch :)I don't feel that I have enough expertise to give the reviewed-by tag, but you cantake my acked-by + tested-by. Acked-by: Jakub Staron <jstaron at google.com> Tested-by: Jakub Staron <jstaron at google.com> No kernel panics/stalls encountered during testing this patches (v9) with QEMU + xfstests. Some CPU stalls encountered while testing with crosvm instead of QEMU with xfstests (test generic/464) but no repro for QEMU, so the fault may be on the side of crosvm. The dump for the crosvm/xfstests stall: [ 2504.175276] rcu: INFO: rcu_sched detected stalls on CPUs/tasks: [ 2504.176681] rcu: 0-...!: (1 GPs behind) idle=9b2/1/0x4000000000000000 softirq=1089198/1089202 fqs=0 [ 2504.178270] rcu: 2-...!: (1 ticks this GP) idle=cfe/1/0x4000000000000002 softirq=1055108/1055110 fqs=0 [ 2504.179802] rcu: 3-...!: (1 GPs behind) idle=1d6/1/0x4000000000000002 softirq=1046798/1046802 fqs=0 [ 2504.181215] rcu: 4-...!: (2 ticks this GP) idle=522/1/0x4000000000000002 softirq=1249063/1249064 fqs=0 [ 2504.182625] rcu: 5-...!: (1 GPs behind) idle=6da/1/0x4000000000000000 softirq=1131036/1131047 fqs=0 [ 2504.183955] (detected by 3, t=0 jiffies, g=1232529, q=1370) [ 2504.184762] Sending NMI from CPU 3 to CPUs 0: [ 2504.186400] NMI backtrace for cpu 0 [ 2504.186401] CPU: 0 PID: 6670 Comm: 464 Not tainted 5.1.0+ #1 [ 2504.186401] Hardware name: ChromiumOS crosvm, BIOS 0 [ 2504.186402] RIP: 0010:queued_spin_lock_slowpath+0x1c/0x1e0 [ 2504.186402] Code: e7 89 c8 f0 44 0f b1 07 39 c1 75 dc f3 c3 0f 1f 44 00 00 ba 01 00 00 00 8b 07 85 c0 75 0a f0 0f b1 17 85 c0 75 f2 f3 c3 f3 90 <eb> ec 81 fe 00 01 00 00 0f 84 ab 00 00 00 81 e6 00 ff ff ff 75 44 [ 2504.186403] RSP: 0018:ffffc90000003ee8 EFLAGS: 00000002 [ 2504.186404] RAX: 0000000000000001 RBX: 0000000000000246 RCX: 0000000000404044 [ 2504.186404] RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffffffff8244a280 [ 2504.186405] RBP: ffffffff8244a280 R08: 00000000000f4200 R09: 0000024709ed6c32 [ 2504.186405] R10: 0000000000000000 R11: 0000000000000001 R12: ffffffff8244a280 [ 2504.186405] R13: 0000000000000009 R14: 0000000000000009 R15: 0000000000000000 [ 2504.186406] FS: 0000000000000000(0000) GS:ffff8880cc600000(0000) knlGS:0000000000000000 [ 2504.186406] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2504.186406] CR2: 00007efd6b0f15d8 CR3: 000000000260a006 CR4: 0000000000360ef0 [ 2504.186407] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 2504.186407] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 2504.186407] Call Trace: [ 2504.186408] <IRQ> [ 2504.186408] _raw_spin_lock_irqsave+0x1d/0x30 [ 2504.186408] rcu_core+0x3b6/0x740 [ 2504.186408] ? __hrtimer_run_queues+0x133/0x280 [ 2504.186409] ? recalibrate_cpu_khz+0x10/0x10 [ 2504.186409] __do_softirq+0xd8/0x2e4 [ 2504.186409] irq_exit+0xa3/0xb0 [ 2504.186410] smp_apic_timer_interrupt+0x67/0x120 [ 2504.186410] apic_timer_interrupt+0xf/0x20 [ 2504.186410] </IRQ> [ 2504.186410] RIP: 0010:unmap_page_range+0x47a/0x9b0 [ 2504.186411] Code: 0f 46 46 10 49 39 6e 18 49 89 46 10 48 89 e8 49 0f 43 46 18 41 80 4e 20 08 4d 85 c9 49 89 46 18 0f 84 68 ff ff ff 49 8b 51 08 <48> 8d 42 ff 83 e2 01 49 0f 44 c1 f6 40 18 01 75 38 48 ba ff 0f 00 [ 2504.186411] RSP: 0018:ffffc900036cbcc8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 [ 2504.186412] RAX: ffffffffffffffff RBX: 800000003751d045 RCX: 0000000000000001 [ 2504.186413] RDX: ffffea0002e09288 RSI: 000000000269b000 RDI: ffff8880b6525e40 [ 2504.186413] RBP: 000000000269c000 R08: 0000000000000000 R09: ffffea0000dd4740 [ 2504.186413] R10: ffffea0001755700 R11: ffff8880cc62d120 R12: 0000000002794000 [ 2504.186414] R13: 000000000269b000 R14: ffffc900036cbdf0 R15: ffff8880572434d8 [ 2504.186414] ? unmap_page_range+0x420/0x9b0 [ 2504.186414] ? release_pages+0x175/0x390 [ 2504.186414] unmap_vmas+0x7c/0xe0 [ 2504.186415] exit_mmap+0xa4/0x190 [ 2504.186415] mmput+0x3b/0x100 [ 2504.186415] do_exit+0x276/0xc10 [ 2504.186415] do_group_exit+0x35/0xa0 [ 2504.186415] __x64_sys_exit_group+0xf/0x10 [ 2504.186416] do_syscall_64+0x43/0x120 [ 2504.186416] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 2504.186416] RIP: 0033:0x7efd6ae10618 [ 2504.186416] Code: Bad RIP value. [ 2504.186417] RSP: 002b:00007ffcac9bde38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 2504.186417] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007efd6ae10618 [ 2504.186418] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 2504.186418] RBP: 00007efd6b0ed8e0 R08: 00000000000000e7 R09: ffffffffffffff98 [ 2504.186418] R10: 00007ffcac9bddb8 R11: 0000000000000246 R12: 00007efd6b0ed8e0 [ 2504.186419] R13: 00007efd6b0f2c20 R14: 0000000000000060 R15: 000000000070e705 [ 2504.186421] NMI backtrace for cpu 3 [ 2504.226980] CPU: 3 PID: 6596 Comm: xfs_io Not tainted 5.1.0+ #1 [ 2504.227661] Hardware name: ChromiumOS crosvm, BIOS 0 [ 2504.228261] Call Trace: [ 2504.228552] <IRQ> [ 2504.228795] dump_stack+0x46/0x5b [ 2504.229180] nmi_cpu_backtrace+0x89/0x90 [ 2504.229649] ? lapic_can_unplug_cpu+0x90/0x90 [ 2504.230157] nmi_trigger_cpumask_backtrace+0x82/0xc0 [ 2504.230751] rcu_dump_cpu_stacks+0x8b/0xb7 [ 2504.231222] rcu_sched_clock_irq+0x6f6/0x720 [ 2504.231726] ? tick_sched_do_timer+0x50/0x50 [ 2504.232214] update_process_times+0x23/0x50 [ 2504.232693] tick_sched_handle+0x2f/0x40 [ 2504.233144] tick_sched_timer+0x32/0x70 [ 2504.233594] __hrtimer_run_queues+0x103/0x280 [ 2504.234092] hrtimer_interrupt+0xe0/0x240 [ 2504.234580] smp_apic_timer_interrupt+0x5d/0x120 [ 2504.235152] apic_timer_interrupt+0xf/0x20 [ 2504.235627] </IRQ> [ 2504.235879] RIP: 0010:__memcpy_flushcache+0x4b/0x180 [ 2504.236452] Code: 8d 5d e0 4c 8d 62 20 48 89 f7 48 29 d7 48 89 d9 48 83 e1 e0 4c 01 e1 48 8d 04 17 4c 8b 02 4c 8b 4a 08 4c 8b 52 10 4c 8b 5a 18 <4c> 0f c3 00 4c 0f c3 48 08 4c 0f c3 50 10 4c 0f c3 58 18 48 83 c2 [ 2504.238592] RSP: 0018:ffffc90003ae38e8 EFLAGS: 00010286 ORIG_RAX: ffffffffffffff13 [ 2504.239467] RAX: ffff888341800000 RBX: 0000000000000fe0 RCX: ffff88801bd22000 [ 2504.240277] RDX: ffff88801bd21000 RSI: ffff888341800000 RDI: 0000000325adf000 [ 2504.241092] RBP: 0000000000001000 R08: cdcdcdcdcdcdcdcd R09: cdcdcdcdcdcdcdcd [ 2504.241908] R10: cdcdcdcdcdcdcdcd R11: cdcdcdcdcdcdcdcd R12: ffff88801bd21020 [ 2504.242751] R13: ffff8880b916b600 R14: ffff888341800000 R15: ffffea00006f4840 [ 2504.243602] write_pmem+0x61/0x90 [ 2504.244002] pmem_do_bvec+0x178/0x2c0 [ 2504.244469] ? chksum_update+0xe/0x20 [ 2504.244908] pmem_make_request+0xf7/0x270 [ 2504.245509] generic_make_request+0x199/0x3f0 [ 2504.246179] ? submit_bio+0x67/0x130 [ 2504.246710] submit_bio+0x67/0x130 [ 2504.247117] ext4_io_submit+0x44/0x50 [ 2504.247556] ext4_writepages+0x621/0xe80 [ 2504.248028] ? 0xffffffff81000000 [ 2504.248418] ? do_writepages+0x46/0xd0 [ 2504.248880] ? ext4_mark_inode_dirty+0x1d0/0x1d0 [ 2504.249417] do_writepages+0x46/0xd0 [ 2504.249833] ? release_pages+0x175/0x390 [ 2504.250290] ? __filemap_fdatawrite_range+0x7c/0xb0 [ 2504.250879] __filemap_fdatawrite_range+0x7c/0xb0 [ 2504.251427] ext4_release_file+0x67/0xa0 [ 2504.251897] __fput+0xb1/0x220 [ 2504.252260] task_work_run+0x79/0xa0 [ 2504.252676] do_exit+0x2ca/0xc10 [ 2504.253063] ? __switch_to_asm+0x40/0x70 [ 2504.253530] ? __switch_to_asm+0x34/0x70 [ 2504.253995] ? __switch_to_asm+0x40/0x70 [ 2504.254446] do_group_exit+0x35/0xa0 [ 2504.254865] get_signal+0x14e/0x7a0 [ 2504.255281] ? __switch_to_asm+0x34/0x70 [ 2504.255749] ? __switch_to_asm+0x40/0x70 [ 2504.256224] do_signal+0x2b/0x5e0 [ 2504.256619] ? __switch_to_asm+0x40/0x70 [ 2504.257086] ? __switch_to_asm+0x34/0x70 [ 2504.257552] ? __switch_to_asm+0x40/0x70 [ 2504.258022] ? __switch_to_asm+0x34/0x70 [ 2504.258488] ? __schedule+0x253/0x530 [ 2504.258943] ? __switch_to_asm+0x34/0x70 [ 2504.259398] exit_to_usermode_loop+0x87/0xa0 [ 2504.259900] do_syscall_64+0xf7/0x120 [ 2504.260326] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 2504.260923] RIP: 0033:0x7faf347e28bd [ 2504.261348] Code: Bad RIP value. [ 2504.261727] RSP: 002b:00007faf33fc5f40 EFLAGS: 00000293 ORIG_RAX: 0000000000000022 [ 2504.262594] RAX: fffffffffffffdfe RBX: 0000000000000000 RCX: 00007faf347e28bd [ 2504.263416] RDX: 8b9da1f4246cdb38 RSI: 0000000000000000 RDI: 0000000000000000 [ 2504.264215] RBP: 0000000000000000 R08: 00007faf33fc6700 R09: 00007faf33fc6700 [ 2504.265061] R10: 000000000000012d R11: 0000000000000293 R12: 00007ffdf142327e [ 2504.266082] R13: 00007ffdf142327f R14: 00007faf337c6000 R15: 0000000000000003 Arch: x86_64 Kernel: stable top with virtio-pmem v9 patches applied Distro: Debian Stretch But as I said, it may be just a problem with crosvm. Thank you, Jakub Staron
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