On Thu, Aug 04 2005, Andrew Vasquez wrote: > All, > > While adding support for the new change_queue_depth/type() callbacks, > > static int > qla2x00_change_queue_depth(struct scsi_device *sdev, int qdepth) > { > scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth); > return sdev->queue_depth; > } > > and updating the queue-depth: > > # echo 16 > /sys/class/scsi_device/3:0:0:0/device/queue_depth > > while I/O is running, I'm hitting a reproducible WARN_ON() triggering > within as_completed_request(): > > static void as_completed_request(request_queue_t *q, struct request *rq) > { > struct as_data *ad = q->elevator->elevator_data; > struct as_rq *arq = RQ_DATA(rq); > > WARN_ON(!list_empty(&rq->queuelist)); Tejun, can you take a look at this please? > ... > > and a subsequent panic: > > Badness in as_completed_request at drivers/block/as-iosched.c:951 > > Call Trace: <IRQ> ffff8024883a>{as_completed_request+63} <ffffffff8024098d>{elv_completed_request+44} > <ffffffff8024272a>{__blk_put_request+73} <ffffffff80280781>{scsi_end_request+164} > <ffffffff802809eb>{scsi_io_completion+584} <ffffffff80297059>{sd_rw_intr+709} > <ffffffff8027aa08>{scsi_finish_command+182} <ffffffff8027b2dc>{scsi_softirq+255} > <ffffffff801291ea>{__do_softirq+110} <ffffffff8010eb13>{call_softirq+31} > <ffffffff801101be>{do_softirq+54} <ffffffff80110211>{do_IRQ+74} > <ffffffff8010deba>{ret_from_intr+0} <EOI> <ffffffff8010c2fd>{mwait_idle+86} > <ffffffff8021aef0>{acpi_processor_idle+310} <ffffffff8010cacb>{cpu_idle+79} > <ffffffff804cecbf>{start_secondary+1017} > ----------- [cut here ] --------- [please bite here ] --------- > Kernel BUG at "drivers/block/ll_rw_blk.c":2361 > invalid operand: 0000 [1] SMP > CPU 2 > Modules linked in: qla2xxx > Pid: 0, comm: swapper Not tainted 2.6.13-rc5 > RIP: 0010:[<ffffffff80242734>] <ffffffff80242734>{__blk_put_request+83} > RSP: 0018:ffff8100021bbde8 EFLAGS: 00010087 > RAX: 0000000000000000 RBX: ffff81002dc738b0 RCX: 0000000000008000 > RDX: 0000000000004e6b RSI: 0000000000000004 RDI: ffff81003e091778 > RBP: ffff81003f8fa600 R08: 0000000000000000 R09: 0000000000000003 > R10: 00000000ffffffff R11: 0000000000000000 R12: 0000000000000000 > R13: 0000000000000001 R14: ffff81003f8fa600 R15: ffff81003f8fa600 > FS: 0000000000000000(0000) GS:ffffffff804b6900(0000) knlGS:0000000000000000 > CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b > CR2: 00002aaaaaac1000 CR3: 0000000037f05000 CR4: 00000000000006e0 > Process swapper (pid: 0, threadinfo ffff8100021b6000, task ffff8100021b54f0) > Stack: ffff81002dc738b0 ffff81002c1cd7c0 0000000000000286 ffffffff80280781 > 0000000000000001 ffff81002c1cd7c0 ffff81002dc738b0 0000000000000000 > 0000000000080000 ffffffff802809eb > Call Trace: <IRQ> <ffffffff80280781>{scsi_end_request+164} <ffffffff802809eb>{scsi_io_completion+584} > <ffffffff80297059>{sd_rw_intr+709} <ffffffff8027aa08>{scsi_finish_command+182} > <ffffffff8027b2dc>{scsi_softirq+255} <ffffffff801291ea>{__do_softirq+110} > <ffffffff8010eb13>{call_softirq+31} <ffffffff801101be>{do_softirq+54} > <ffffffff80110211>{do_IRQ+74} <ffffffff8010deba>{ret_from_intr+0} > <EOI> <ffffffff8010c2fd>{mwait_idle+86} <ffffffff8021aef0>{acpi_processor_idle+310} > <ffffffff8010cacb>{cpu_idle+79} <ffffffff804cecbf>{start_secondary+1017} > > Code: 0f 0b a3 0b f2 32 80 ff ff ff ff c2 39 09 48 89 de 48 89 ef > RIP <ffffffff80242734>{__blk_put_request+83} RSP <ffff8100021bbde8> > <3>Debug: sleeping function called from invalid context at include/linux/rwsem.h:43 > in_atomic():1, irqs_disabled():1 > > Call Trace: <IRQ> <ffffffff8011e2d7>{__might_sleep+199} <ffffffff80125316>{profile_task_exit+34} > <ffffffff80126fe2>{do_exit+34} <ffffffff801fc7d0>{vgacon_cursor+231} > <ffffffff8010f653>{kernel_math_error+0} <ffffffff8010fa09>{do_trap+264} > <ffffffff8010feb9>{do_invalid_op+145} <ffffffff80242734>{__blk_put_request+83} > <ffffffff801245d7>{printk+141} <ffffffff8010e415>{error_exit+0} > <ffffffff80242734>{__blk_put_request+83} <ffffffff8024272a>{__blk_put_request+73} > <ffffffff80280781>{scsi_end_request+164} <ffffffff802809eb>{scsi_io_completion+584} > <ffffffff80297059>{sd_rw_intr+709} <ffffffff8027aa08>{scsi_finish_command+182} > <ffffffff8027b2dc>{scsi_softirq+255} <ffffffff801291ea>{__do_softirq+110} > <ffffffff8010eb13>{call_softirq+31} <ffffffff801101be>{do_softirq+54} > <ffffffff80110211>{do_IRQ+74} <ffffffff8010deba>{ret_from_intr+0} > <EOI> <ffffffff8010c2fd>{mwait_idle+86} <ffffffff8021aef0>{acpi_processor_idle+310} > <ffffffff8010cacb>{cpu_idle+79} <ffffffff804cecbf>{start_secondary+1017} > > Kernel panic - not syncing: Aiee, killing interrupt handler! > > Adding scsi_target_quiesce() and scsi_target_resume() barriers around > the scsi_adjust_target_queue_depth() call appears to help (i.e. > dropping from 32 -> 24): > > # echo 24 > /sys/class/scsi_device/3\:0\:0\:0/device/queue_depth > > and dropping down again to 16: > > # echo 16 > /sys/class/scsi_device/3\:0\:0\:0/device/queue_depth > > but occasionally, while trying another depth drop: > > # echo 10 > /sys/class/scsi_device/3\:0\:0\:0/device/queue_depth > > I'll either get a panic (haven't captured a good one yet (only a > couple of line within the trace): > > eip: ffffffff80248a62 > ----------- [cut here ] --------- [please bite here ] --------- > Kernel BUG at "include/asm/spinlock.h":121 > > or I get the following slab-error: > > slab error in cache_free_debugcheck(): cache `size-128': double free, or memory outside object was overwritten > > Call Trace:<ffffffff8014930c>{cache_free_debugcheck+290} <ffffffff8014975c>{kfree+136} > <ffffffff80244e65>{blk_queue_resize_tags+119} <ffffffff8027a826>{scsi_adjust_queue_depth+68} > <ffffffff88000133>{:qla2xxx:qla2x00_change_queue_depth+71} > <ffffffff80283666>{sdev_store_queue_depth_rw+82} <ffffffff8023a9a2>{dev_attr_store+31} > <ffffffff80191e95>{sysfs_write_file+200} <ffffffff80160dba>{vfs_write+172} > <ffffffff80160ed8>{sys_write+69} <ffffffff8010d8f6>{system_call+126} > > ffff8100389baba8: redzone 1: 0x170fc2a5, redzone 2: 0x0. > > I'm using a fairly recent snapshot of Linus' GIT tree (sync done > earlier today). > > Two questions: > > - must the target be quiesced before adjusting the queue-depth? > > - any ideas on where why successive lowering of the depth borks the > machine? > > Thanks, > Andrew Vasquez > - > : send the line "unsubscribe linux-scsi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Jens Axboe - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html