On 01/13/2017 09:15 AM, Hannes Reinecke wrote: > On 01/11/2017 10:39 PM, Jens Axboe wrote: >> Another year, another posting of this patchset. The previous posting >> was here: >> >> https://www.spinics.net/lists/kernel/msg2406106.html >> >> (yes, I've skipped v5, it was fixes on top of v4, not the rework). >> >> I've reworked bits of this to get rid of the shadow requests, thanks >> to Bart for the inspiration. The missing piece, for me, was the fact >> that we have the tags->rqs[] indirection array already. I've done this >> somewhat differently, though, by having the internal scheduler tag >> map be allocated/torn down when an IO scheduler is attached or >> detached. This also means that when we run without a scheduler, we >> don't have to do double tag allocations, it'll work like before. >> >> The patchset applies on top of 4.10-rc3, or can be pulled here: >> >> git://git.kernel.dk/linux-block blk-mq-sched.6 >> > Well ... something's wrong here on my machine: > > [ 39.886886] ------------[ cut here ]------------ > [ 39.886895] WARNING: CPU: 9 PID: 62 at block/blk-mq.c:342 > __blk_mq_finish_request+0x124/0x140 > [ 39.886895] Modules linked in: sd_mod ahci uhci_hcd ehci_pci > mpt3sas(+) libahci ehci_hcd serio_raw crc32c_intel raid_class drm libata > usbcore hpsa usb_common scsi_transport_sas sg dm_multipath dm_mod > scsi_dh_rdac scsi_dh_emc scsi_dh_alua autofs4 > [ 39.886910] CPU: 9 PID: 62 Comm: kworker/u130:0 Not tainted > 4.10.0-rc3+ #528 > [ 39.886911] Hardware name: HP ProLiant ML350p Gen8, BIOS P72 09/08/2013 > [ 39.886917] Workqueue: events_unbound async_run_entry_fn > [ 39.886918] Call Trace: > [ 39.886923] dump_stack+0x85/0xc9 > [ 39.886927] __warn+0xd1/0xf0 > [ 39.886928] warn_slowpath_null+0x1d/0x20 > [ 39.886930] __blk_mq_finish_request+0x124/0x140 > [ 39.886932] blk_mq_finish_request+0x55/0x60 > [ 39.886934] blk_mq_sched_put_request+0x78/0x80 > [ 39.886936] blk_mq_free_request+0xe/0x10 > [ 39.886938] blk_put_request+0x25/0x60 > [ 39.886944] __scsi_execute.isra.24+0x104/0x160 > [ 39.886946] scsi_execute_req_flags+0x94/0x100 > [ 39.886948] scsi_report_opcode+0xab/0x100 > > checking ... > Ah. Seems like the elevator switch races with device setup: 1188.490326] ------------[ cut here ]------------ [ 1188.490334] WARNING: CPU: 9 PID: 30155 at block/blk-mq.c:342 __blk_mq_finish_request+0x172/0x180 [ 1188.490335] Modules linked in: mpt3sas(+) raid_class rpcsec_gss_krb5 auth_rpcgss nfsv4 nfs lockd grace fscache ebtable_filt er ebtables ip6table_filter ip6_tables iptable_filter ip_tables x_tables af_packet br_netfilter bridge stp llc iscsi_ibft iscs i_boot_sysfs sb_edac edac_core x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_p clmul tg3 ixgbe ghash_clmulni_intel pcbc ptp aesni_intel pps_core aes_x86_64 ipmi_ssif hpilo hpwdt mdio libphy pcc_cpufreq cry pto_simd glue_helper iTCO_wdt iTCO_vendor_support acpi_cpufreq tpm_tis ipmi_si ipmi_devintf cryptd lpc_ich pcspkr ioatdma tpm_ tis_core thermal wmi shpchp dca ipmi_msghandler tpm fjes button sunrpc btrfs xor sr_mod raid6_pq cdrom ehci_pci mgag200 i2c_al go_bit drm_kms_helper syscopyarea sysfillrect uhci_hcd [ 1188.490399] sysimgblt fb_sys_fops sd_mod ahci ehci_hcd ttm libahci crc32c_intel serio_raw drm libata usbcore usb_common hp sa scsi_transport_sas sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua autofs4 [ 1188.490411] CPU: 9 PID: 30155 Comm: kworker/u130:6 Not tainted 4.10.0-rc3+ #535 [ 1188.490411] Hardware name: HP ProLiant ML350p Gen8, BIOS P72 09/08/2013 [ 1188.490425] Workqueue: events_unbound async_run_entry_fn [ 1188.490427] Call Trace: [ 1188.490433] dump_stack+0x85/0xc9 [ 1188.490436] __warn+0xd1/0xf0 [ 1188.490438] warn_slowpath_null+0x1d/0x20 [ 1188.490440] __blk_mq_finish_request+0x172/0x180 [ 1188.490442] blk_mq_finish_request+0x55/0x60 [ 1188.490443] blk_mq_sched_put_request+0x78/0x80 [ 1188.490445] blk_mq_free_request+0xe/0x10 [ 1188.490448] blk_put_request+0x25/0x60 [ 1188.490453] __scsi_execute.isra.24+0x104/0x160 [ 1188.490455] scsi_execute_req_flags+0x94/0x100 [ 1188.490457] scsi_report_opcode+0xab/0x100 [ 1188.490461] sd_revalidate_disk+0xaef/0x1450 [sd_mod] [ 1188.490464] sd_probe_async+0xd1/0x1d0 [sd_mod] [ 1188.490466] async_run_entry_fn+0x37/0x150 [ 1188.490470] process_one_work+0x1d0/0x660 [ 1188.490472] ? process_one_work+0x151/0x660 [ 1188.490474] worker_thread+0x12b/0x4a0 [ 1188.490475] kthread+0x10c/0x140 [ 1188.490477] ? process_one_work+0x660/0x660 [ 1188.490478] ? kthread_create_on_node+0x40/0x40 [ 1188.490483] ret_from_fork+0x2a/0x40 [ 1188.490484] ---[ end trace d5e3a32ac269fc2a ]--- [ 1188.490485] rq (487/52) rqs (-1/-1) [ 1188.523518] sd 7:0:0:0: [sdb] Attached SCSI disk [ 1188.540954] elevator: switch to deadline failed (The 'rqs' line is a debug output from me: struct request *rqs_rq = hctx->tags->rqs[rq->tag]; printk(KERN_WARNING "rq (%d/%d) rqs (%d/%d)\n", rq->tag, sched_tag, rqs_rq ? rqs_rq->tag : -1, rqs_rq ? rqs_rq->internal_tag : -1); telling us that request with 'tag' 487 is _not_ at position 487 in the rqs array; rather that position is empty. Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@xxxxxxx +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
