Re: [PATCH v11] NVMe: Convert to blk-mq
From: Keith Busch
Date: Wed Aug 13 2014 - 18:27:42 EST
On Sun, 10 Aug 2014, Matias BjÃrling wrote:
On Sat, Jul 26, 2014 at 11:07 AM, Matias BjÃrling <m@xxxxxxxxxxx> wrote:
This converts the NVMe driver to a blk-mq request-based driver.
Willy, do you need me to make any changes to the conversion? Can you
pick it up for 3.17?
Hi Matias,
I'm starting to get a little more spare time to look at this again. I
think there are still some bugs here, or perhaps something better we
can do. I'll just start with one snippet of the code:
@@ -765,33 +619,49 @@ static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
submit_iod:
spin_lock_irq(&nvmeq->q_lock);
if (nvmeq->q_suspended) {
spin_unlock_irq(&nvmeq->q_lock);
goto finish_cmd;
}
<snip>
finish_cmd:
nvme_finish_cmd(nvmeq, req->tag, NULL);
nvme_free_iod(nvmeq->dev, iod);
return result;
}
If the nvme queue is marked "suspended", this code just goto's the finish
without setting "result", so I don't think that's right.
But do we even need the "q_suspended" flag anymore? It was there because
we couldn't prevent incoming requests as a bio based driver and we needed
some way to mark that the h/w's IO queue was temporarily inactive, but
blk-mq has ways to start/stop a queue at a higher level, right? If so,
I think that's probably a better way than using this driver specific way.
I haven't event tried debugging this next one: doing an insmod+rmmod
caused this warning followed by a panic:
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207525] ------------[ cut here ]------------
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207538] WARNING: CPU: 8 PID: 5768 at mm/slab_common.c:491 kmalloc_slab+0x33/0x8b()
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207541] Modules linked in: nvme(-) parport_pc ppdev lp parport dlm sctp libcrc32c configfs nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc md4 hmac cifs bridge stp llc jfs joydev hid_generic usbhid hid loop md_mod x86_pkg_temp_thermal coretemp kvm_intel kvm iTCO_wdt iTCO_vendor_support microcode pcspkr ehci_pci ehci_hcd usbcore acpi_cpufreq lpc_ich usb_common ioatdma mfd_core i2c_i801 evdev wmi tpm_tis ipmi_si tpm ipmi_msghandler processor thermal_sys button ext4 crc16 jbd2 mbcache sg sr_mod cdrom sd_mod crct10dif_generic crc_t10dif crct10dif_common nbd dm_mod crc32c_intel ghash_clmulni_intel aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd isci libsas igb ahci libahci scsi_transport_sas ptp pps_core libata i2c_algo_bit i2c_core scsi_mod dca
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207653] CPU: 8 PID: 5768 Comm: nvme1 Not tainted 3.16.0-rc6+ #24
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207656] Hardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207659] 0000000000000000 0000000000000009 ffffffff8139f9ba 0000000000000000
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207664] ffffffff8103db86 ffffe8ffff601d80 ffffffff810f0d59 0000000000000246
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207669] 0000000000000000 ffff880827bf28c0 0000000000008020 ffff88082b8d9d00
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207674] Call Trace:
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207685] [<ffffffff8139f9ba>] ? dump_stack+0x41/0x51
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207694] [<ffffffff8103db86>] ? warn_slowpath_common+0x7d/0x95
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207699] [<ffffffff810f0d59>] ? kmalloc_slab+0x33/0x8b
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207704] [<ffffffff810f0d59>] ? kmalloc_slab+0x33/0x8b
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207710] [<ffffffff81115329>] ? __kmalloc+0x28/0xf1
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207719] [<ffffffff811d0daf>] ? blk_mq_tag_busy_iter+0x30/0x7c
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207728] [<ffffffffa052c426>] ? nvme_init_hctx+0x49/0x49 [nvme]
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207733] [<ffffffff811d0daf>] ? blk_mq_tag_busy_iter+0x30/0x7c
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207738] [<ffffffffa052c98b>] ? nvme_clear_queue+0x72/0x7d [nvme]
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207744] [<ffffffffa052c9a8>] ? nvme_del_queue_end+0x12/0x26 [nvme]
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207750] [<ffffffff810576e3>] ? kthread_worker_fn+0xb1/0x111
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207754] [<ffffffff81057632>] ? kthread_create_on_node+0x171/0x171
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207758] [<ffffffff81057632>] ? kthread_create_on_node+0x171/0x171
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207762] [<ffffffff810574b9>] ? kthread+0x9e/0xa6
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207766] [<ffffffff8105741b>] ? __kthread_parkme+0x5c/0x5c
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207773] [<ffffffff813a3a2c>] ? ret_from_fork+0x7c/0xb0
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207777] [<ffffffff8105741b>] ? __kthread_parkme+0x5c/0x5c
Aug 13 15:41:41 kbgrz1 kernel: [ 89.207780] ---[ end trace 8dc4a4c97c467d4c ]---
Aug 13 15:41:41 kbgrz1 kernel: [ 89.223627] PGD 0
Aug 13 15:41:41 kbgrz1 kernel: [ 89.226038] Oops: 0000 [#1] SMP
Aug 13 15:41:41 kbgrz1 kernel: [ 89.229917] Modules linked in: nvme(-) parport_pc ppdev lp parport dlm sctp libcrc32c configfs nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc md4 hmac cifs bridge stp llc jfs joydev hid_generic usbhid hid loop md_mod x86_pkg_temp_thermal coretemp kvm_intel kvm iTCO_wdt iTCO_vendor_support microcode pcspkr ehci_pci ehci_hcd usbcore acpi_cpufreq lpc_ich usb_common ioatdma mfd_core i2c_i801 evdev wmi tpm_tis ipmi_si tpm ipmi_msghandler processor thermal_sys button ext4 crc16 jbd2 mbcache sg sr_mod cdrom sd_mod crct10dif_generic crc_t10dif crct10dif_common nbd dm_mod crc32c_intel ghash_clmulni_intel aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd isci libsas igb ahci libahci scsi_transport_sas ptp pps_core libata i2c_algo_bit i2c_core scsi_mod dca
Aug 13 15:41:41 kbgrz1 kernel: [ 89.315211] CPU: 8 PID: 5768 Comm: nvme1 Tainted: G W 3.16.0-rc6+ #24
Aug 13 15:41:41 kbgrz1 kernel: [ 89.323563] Hardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013
Aug 13 15:41:41 kbgrz1 kernel: [ 89.335121] task: ffff88042ad92d70 ti: ffff880425ff0000 task.ti: ffff880425ff0000
Aug 13 15:41:41 kbgrz1 kernel: [ 89.343574] RIP: 0010:[<ffffffff811d0d38>] [<ffffffff811d0d38>] bt_for_each_free+0x31/0x78
Aug 13 15:41:41 kbgrz1 kernel: [ 89.353144] RSP: 0018:ffff880425ff3de8 EFLAGS: 00010086
Aug 13 15:41:41 kbgrz1 kernel: [ 89.359189] RAX: 0000000000000010 RBX: ffffffffffffffff RCX: 0000000000000007
Aug 13 15:41:41 kbgrz1 kernel: [ 89.367276] RDX: 0000000000000000 RSI: 0000000000000010 RDI: ffff880827bf2850
Aug 13 15:41:41 kbgrz1 kernel: [ 89.375362] RBP: 0000000000000000 R08: 000000000000000f R09: 00000000fffffffe
Aug 13 15:41:41 kbgrz1 kernel: [ 89.383448] R10: 0000000000000000 R11: 0000000000000046 R12: ffff880827bf2850
Aug 13 15:41:41 kbgrz1 kernel: [ 89.391534] R13: 00000000ffffffff R14: 0000000000000010 R15: 0000000000000001
Aug 13 15:41:41 kbgrz1 kernel: [ 89.399622] FS: 0000000000000000(0000) GS:ffff88083f200000(0000) knlGS:0000000000000000
Aug 13 15:41:41 kbgrz1 kernel: [ 89.408805] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Aug 13 15:41:41 kbgrz1 kernel: [ 89.415340] CR2: 0000000000000007 CR3: 0000000001610000 CR4: 00000000000407e0
Aug 13 15:41:41 kbgrz1 kernel: [ 89.423426] Stack:
Aug 13 15:41:41 kbgrz1 kernel: [ 89.425775] 0000000000000007 0000000000000010 ffff880827bf2840 ffffffffa052c426
Aug 13 15:41:41 kbgrz1 kernel: [ 89.434515] ffff88082b8d9f00 ffff88042ad92d70 0000000000000000 ffffffff811d0dc6
Aug 13 15:41:41 kbgrz1 kernel: [ 89.443254] 00000000fffffffe ffff88082b8d9f00 ffff88082b8d9f28 ffff88042ad92d70
Aug 13 15:41:41 kbgrz1 kernel: [ 89.452012] Call Trace:
Aug 13 15:41:41 kbgrz1 kernel: [ 89.454852] [<ffffffffa052c426>] ? nvme_init_hctx+0x49/0x49 [nvme]
Aug 13 15:41:41 kbgrz1 kernel: [ 89.461968] [<ffffffff811d0dc6>] ? blk_mq_tag_busy_iter+0x47/0x7c
Aug 13 15:41:41 kbgrz1 kernel: [ 89.468987] [<ffffffffa052c98b>] ? nvme_clear_queue+0x72/0x7d [nvme]
Aug 13 15:41:41 kbgrz1 kernel: [ 89.476298] [<ffffffffa052c9a8>] ? nvme_del_queue_end+0x12/0x26 [nvme]
Aug 13 15:41:41 kbgrz1 kernel: [ 89.483801] [<ffffffff810576e3>] ? kthread_worker_fn+0xb1/0x111
Aug 13 15:41:41 kbgrz1 kernel: [ 89.490625] [<ffffffff81057632>] ? kthread_create_on_node+0x171/0x171
Aug 13 15:41:41 kbgrz1 kernel: [ 89.498038] [<ffffffff81057632>] ? kthread_create_on_node+0x171/0x171
Aug 13 15:41:41 kbgrz1 kernel: [ 89.505446] [<ffffffff810574b9>] ? kthread+0x9e/0xa6
Aug 13 15:41:41 kbgrz1 kernel: [ 89.511200] [<ffffffff8105741b>] ? __kthread_parkme+0x5c/0x5c
Aug 13 15:41:41 kbgrz1 kernel: [ 89.517833] [<ffffffff813a3a2c>] ? ret_from_fork+0x7c/0xb0
Aug 13 15:41:41 kbgrz1 kernel: [ 89.524170] [<ffffffff8105741b>] ? __kthread_parkme+0x5c/0x5c
Aug 13 15:41:41 kbgrz1 kernel: [ 89.530799] Code: 57 41 bf 01 00 00 00 41 56 49 89 f6 41 55 41 89 d5 41 54 49 89 fc 55 31 ed 53 51 eb 42 48 63 dd 31 d2 48 c1 e3 06 49 03 5c 24 10 <48> 8b 73 08 48 63 d2 48 89 df e8 e2 28 02 00 48 63 c8 48 3b 4b
Aug 13 15:41:41 kbgrz1 kernel: [ 89.564696] RSP <ffff880425ff3de8>
Aug 13 15:41:41 kbgrz1 kernel: [ 89.568699] CR2: 0000000000000007
Aug 13 15:41:41 kbgrz1 kernel: [ 89.572518] ---[ end trace 8dc4a4c97c467d4d ]---