may somebody of VMware Inc. please take a look at https://bugzilla.redhat.com/show_bug.cgi?id=926917 these messages appear in dmesg in case of debug-kernels for a long time and given that we speak about the main storage driver that leaves a bad taste [ 15.641689] scsi2 : VMware PVSCSI storage adapter rev 2, req/cmp/msg rings: 8/8/1 pages, cmd_per_lun=64 [ 15.650348] vmw_pvscsi 0000:13:00.0: VMware PVSCSI rev 2 host #2 [ 15.656531] ------------[ cut here ]------------ [ 15.657055] WARNING: CPU: 0 PID: 6 at lib/dma-debug.c:937 check_unmap+0x47b/0x920() [ 15.657577] vmw_pvscsi 0000:13:00.0: DMA-API: device driver failed to check map error[device address=0x0000000028cbcc40] [size=96 bytes] [mapped as single] [ 15.658483] Modules linked in: [ 15.659064] vmw_pvscsi(+) [ 15.659460] CPU: 0 PID: 6 Comm: kworker/u2:0 Not tainted 3.14.0-0.rc0.git3.1.fc21.x86_64 #1 [ 15.660174] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013 [ 15.661267] Workqueue: events_unbound async_run_entry_fn [ 15.661944] 0000000000000009 ffff88002fc03ad8 ffffffff817685b8 ffff88002fc03b20 [ 15.662548] ffff88002fc03b10 ffffffff8107ad3d ffff88002d24f2d0 ffff88002c51ee38 [ 15.663353] ffffffff82d6b950 0000000000000086 ffffffff81a23e5b ffff88002fc03b70 [ 15.664135] Call Trace: [ 15.664481] <IRQ> [<ffffffff817685b8>] dump_stack+0x4d/0x66 [ 15.665162] [<ffffffff8107ad3d>] warn_slowpath_common+0x7d/0xa0 [ 15.665626] [<ffffffff8107adac>] warn_slowpath_fmt+0x4c/0x50 [ 15.666272] [<ffffffff813b523b>] check_unmap+0x47b/0x920 [ 15.666941] [<ffffffff813b582d>] ? debug_dma_unmap_sg+0x6d/0x130 [ 15.667574] [<ffffffff813b573f>] debug_dma_unmap_page+0x5f/0x70 [ 15.668141] [<ffffffffa00006ba>] pvscsi_unmap_buffers.isra.12+0x11a/0x1f0 [vmw_pvscsi] [ 15.668912] [<ffffffffa0000896>] pvscsi_process_completion_ring+0x106/0x2d0 [vmw_pvscsi] [ 15.669496] [<ffffffffa0000b14>] pvscsi_isr+0x34/0xa0 [vmw_pvscsi] [ 15.670171] [<ffffffff810ed3fe>] handle_irq_event_percpu+0x3e/0x370 [ 15.670661] [<ffffffff810ed76d>] handle_irq_event+0x3d/0x60 [ 15.671305] [<ffffffff810f0257>] handle_edge_irq+0x77/0x130 [ 15.671935] [<ffffffff8101bbaf>] handle_irq+0xbf/0x150 [ 15.672385] [<ffffffff81081aa2>] ? irq_enter+0x42/0x90 [ 15.673000] [<ffffffff8177d34f>] do_IRQ+0x4f/0xf0 [ 15.673521] [<ffffffff81771eb2>] common_interrupt+0x72/0x72 [ 15.674089] [<ffffffff810814e8>] ? __do_softirq+0xc8/0x460 [ 15.674557] [<ffffffff810814e1>] ? __do_softirq+0xc1/0x460 [ 15.675196] [<ffffffff810bd8d1>] ? sched_clock_cpu+0x11/0xd0 [ 15.675670] [<ffffffff81081bb5>] irq_exit+0xc5/0xd0 [ 15.676285] [<ffffffff8177d435>] smp_apic_timer_interrupt+0x45/0x60 [ 15.676927] [<ffffffff8177bd72>] apic_timer_interrupt+0x72/0x80 [ 15.677410] <EOI> [<ffffffff8177119b>] ? _raw_spin_unlock_irqrestore+0x3b/0x70 [ 15.678148] [<ffffffffa0001750>] pvscsi_queue+0x130/0x830 [vmw_pvscsi] [ 15.678661] [<ffffffff814ce2f0>] ? perf_trace_scsi_dispatch_cmd_error+0x1a0/0x1a0 [ 15.679367] [<ffffffff814ce8f1>] scsi_dispatch_cmd+0xb1/0x4e0 [ 15.679999] [<ffffffff814d627c>] scsi_request_fn+0x33c/0x540 [ 15.680469] [<ffffffff8135a603>] __blk_run_queue+0x33/0x40 [ 15.681095] [<ffffffff81363241>] blk_execute_rq_nowait+0xa1/0x120 [ 15.681579] [<ffffffff81363366>] blk_execute_rq+0x76/0x100 [ 15.682213] [<ffffffff8135911f>] ? blk_rq_init+0xff/0x170 [ 15.682707] [<ffffffff81363650>] ? blk_recount_segments+0x20/0x40 [ 15.683359] [<ffffffff81241209>] ? bio_phys_segments+0x19/0x20 [ 15.684013] [<ffffffff8135e890>] ? blk_rq_bio_prep+0x70/0xd0 [ 15.684469] [<ffffffff813630f0>] ? blk_rq_map_kern+0xc0/0x170 [ 15.685107] [<ffffffff814d4d87>] scsi_execute+0xd7/0x160 [ 15.685556] [<ffffffff814d656c>] scsi_execute_req_flags+0x8c/0x100 [ 15.686201] [<ffffffff814d898c>] scsi_probe_and_add_lun+0x20c/0xc00 [ 15.686687] [<ffffffff814d97f8>] __scsi_scan_target+0xf8/0x6a0 [ 15.687330] [<ffffffff810d8339>] ? mark_held_locks+0xb9/0x140 [ 15.687986] [<ffffffff81771196>] ? _raw_spin_unlock_irqrestore+0x36/0x70 [ 15.692147] [<ffffffff810d84c5>] ? trace_hardirqs_on_caller+0x105/0x1d0 [ 15.692661] [<ffffffff810d859d>] ? trace_hardirqs_on+0xd/0x10 [ 15.693345] [<ffffffff814d9f16>] scsi_scan_channel.part.6+0x66/0x90 [ 15.694016] [<ffffffff814da0d9>] scsi_scan_host_selected+0xf9/0x1c0 [ 15.694497] [<ffffffff814da231>] do_scsi_scan_host+0x91/0xa0 [ 15.695125] [<ffffffff814da40c>] do_scan_async+0x1c/0x160 [ 15.695574] [<ffffffff810ae389>] async_run_entry_fn+0x39/0x120 [ 15.696229] [<ffffffff8109d4c1>] process_one_work+0x211/0x6b0 [ 15.696689] [<ffffffff8109d455>] ? process_one_work+0x1a5/0x6b0 [ 15.697332] [<ffffffff8109da7b>] worker_thread+0x11b/0x3a0 [ 15.697958] [<ffffffff8109d960>] ? process_one_work+0x6b0/0x6b0 [ 15.698423] [<ffffffff810a6550>] kthread+0xf0/0x110 [ 15.699031] [<ffffffff81021f59>] ? sched_clock+0x9/0x10 [ 15.699472] [<ffffffff810a6460>] ? insert_kthread_work+0x80/0x80 [ 15.700112] [<ffffffff8177afbc>] ret_from_fork+0x7c/0xb0 [ 15.700587] [<ffffffff810a6460>] ? insert_kthread_work+0x80/0x80 [ 15.701261] ---[ end trace 9e665d6a1a3e2037 ]--- [ 15.701676] Mapped at: [ 15.702234] [<ffffffff813b4081>] debug_dma_map_page+0x91/0x140 [ 15.702722] [<ffffffffa00018a1>] pvscsi_queue+0x281/0x830 [vmw_pvscsi] [ 15.703360] [<ffffffff814ce8f1>] scsi_dispatch_cmd+0xb1/0x4e0 [ 15.704018] [<ffffffff814d627c>] scsi_request_fn+0x33c/0x540 [ 15.704530] [<ffffffff8135a603>] __blk_run_queue+0x33/0x40 [ 15.706915] scsi 2:0:0:0: Direct-Access VMware, VMware Virtual S 1.0 PQ: 0 ANSI: 2 [ 15.708230] scsi 2:0:1:0: Direct-Access VMware, VMware Virtual S 1.0 PQ: 0 ANSI: 2