On Fri, Jan 13 2017, Hannes Reinecke wrote: > 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: Huh, funky, haven't seen that. I'll see if I can reproduce it here. I don't have SCAN_ASYNC turned on, on my test box. -- Jens Axboe -- 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
