Re: [PATCH] blk-mq: only run mapped hw queues in blk_mq_run_hw_queues()
From: Christian Borntraeger <hidden>
Date: 2018-03-28 15:36:53
On 03/28/2018 05:26 PM, Ming Lei wrote:
Hi Christian, On Wed, Mar 28, 2018 at 09:45:10AM +0200, Christian Borntraeger wrote:quoted
FWIW, this patch does not fix the issue for me: ostname=? addr=? terminal=? res=success' [ 21.454961] WARNING: CPU: 3 PID: 1882 at block/blk-mq.c:1410 __blk_mq_delay_run_hw_queue+0xbe/0xd8 [ 21.454968] Modules linked in: scsi_dh_rdac scsi_dh_emc scsi_dh_alua dm_mirror dm_region_hash dm_log dm_multipath dm_mod autofs4 [ 21.454984] CPU: 3 PID: 1882 Comm: dasdconf.sh Not tainted 4.16.0-rc7+ #26 [ 21.454987] Hardware name: IBM 2964 NC9 704 (LPAR) [ 21.454990] Krnl PSW : 00000000c0131ea3 000000003ea2f7bf (__blk_mq_delay_run_hw_queue+0xbe/0xd8) [ 21.454996] R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 [ 21.455005] Krnl GPRS: 0000013abb69a000 0000013a00000000 0000013ac6c0dc00 0000000000000001 [ 21.455008] 0000000000000000 0000013abb69a710 0000013a00000000 00000001b691fd98 [ 21.455011] 00000001b691fd98 0000013ace4775c8 0000000000000001 0000000000000000 [ 21.455014] 0000013ac6c0dc00 0000000000b47238 00000001b691fc08 00000001b691fbd0 [ 21.455032] Krnl Code: 000000000069c596: ebaff0a00004 lmg %r10,%r15,160(%r15) 000000000069c59c: c0f4ffff7a5e brcl 15,68ba58 #000000000069c5a2: a7f40001 brc 15,69c5a4 >000000000069c5a6: e340f0c00004 lg %r4,192(%r15) 000000000069c5ac: ebaff0a00004 lmg %r10,%r15,160(%r15) 000000000069c5b2: 07f4 bcr 15,%r4 000000000069c5b4: c0e5fffffeea brasl %r14,69c388 000000000069c5ba: a7f4fff6 brc 15,69c5a6 [ 21.455067] Call Trace: [ 21.455072] ([<00000001b691fd98>] 0x1b691fd98) [ 21.455079] [<000000000069c692>] blk_mq_run_hw_queue+0xba/0x100 [ 21.455083] [<000000000069c740>] blk_mq_run_hw_queues+0x68/0x88 [ 21.455089] [<000000000069b956>] __blk_mq_complete_request+0x11e/0x1d8 [ 21.455091] [<000000000069ba9c>] blk_mq_complete_request+0x8c/0xc8 [ 21.455103] [<00000000008aa250>] dasd_block_tasklet+0x158/0x490 [ 21.455110] [<000000000014c742>] tasklet_hi_action+0x92/0x120 [ 21.455118] [<0000000000a7cfc0>] __do_softirq+0x120/0x348 [ 21.455122] [<000000000014c212>] irq_exit+0xba/0xd0 [ 21.455130] [<000000000010bf92>] do_IRQ+0x8a/0xb8 [ 21.455133] [<0000000000a7c298>] io_int_handler+0x130/0x298 [ 21.455136] Last Breaking-Event-Address: [ 21.455138] [<000000000069c5a2>] __blk_mq_delay_run_hw_queue+0xba/0xd8 [ 21.455140] ---[ end trace be43f99a5d1e553e ]--- [ 21.510046] dasdconf.sh Warning: 0.0.241e is already online, not configuringThinking about this issue further, I can't understand the root cause for this issue. After commit 20e4d813931961fe ("blk-mq: simplify queue mapping & schedule with each possisble CPU"), each hw queue should be mapped to at least one CPU, that means this issue shouldn't happen. Maybe blk_mq_map_queues() works wrong? Could you dump 'lscpu' and provide blk-mq debugfs for your DASD via the following command?
# lscpu Architecture: s390x CPU op-mode(s): 32-bit, 64-bit Byte Order: Big Endian CPU(s): 16 On-line CPU(s) list: 0-15 Thread(s) per core: 2 Core(s) per socket: 8 Socket(s) per book: 3 Book(s) per drawer: 2 Drawer(s): 4 NUMA node(s): 1 Vendor ID: IBM/S390 Machine type: 2964 CPU dynamic MHz: 5000 CPU static MHz: 5000 BogoMIPS: 20325.00 Hypervisor: PR/SM Hypervisor vendor: IBM Virtualization type: full Dispatching mode: horizontal L1d cache: 128K L1i cache: 96K L2d cache: 2048K L2i cache: 2048K L3 cache: 65536K L4 cache: 491520K NUMA node0 CPU(s): 0-15 Flags: esan3 zarch stfle msa ldisp eimm dfp edat etf3eh highgprs te vx sie # lsdasd Bus-ID Status Name Device Type BlkSz Size Blocks ============================================================================== 0.0.3f75 active dasda 94:0 ECKD 4096 21129MB 5409180 0.0.3f76 active dasdb 94:4 ECKD 4096 21129MB 5409180 0.0.3f77 active dasdc 94:8 ECKD 4096 21129MB 5409180 0.0.3f74 active dasdd 94:12 ECKD 4096 21129MB 5409180
(cd /sys/kernel/debug/block/$DASD && find . -type f -exec grep -aH . {} \;)see attachement: