On Thu, Jun 4, 2009 at 2:02 AM, FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> wrote: > On Wed, 3 Jun 2009 21:30:32 +0200 > Torsten Kaiser <just.for.lkml@xxxxxxxxxxxxxx> wrote: >> Still happens with 2.6.30-rc8 (see trace at the end of the email) >> >> As orig_n_elem is only used two times in libata-core.c I suspected a >> corruption of the qc->sg, but adding checks for this did not trigger. >> So I looked into lib/dma-debug.c. >> It seems add_dma_entry() does not protect against adding the same >> entry twice. > > Do you mean that add_dma_entry() doesn't protect against adding a new > entry identical to the existing entry, right? Yes, as I read the hash bucket code in lib/dma-debug.c a second entry from the same device and the same address will just be added to the list and on unmap it will always return the first entry. > Then it's not a > dma-debug bug (it might be better for dma-debug to check it though), > that is, such situation should not happen. At least the warning about the wrong unmap count is a bug in the dma-debug, as that is not what happens on my system. > Probably, it's an IOMMU bug > or a driver bug. Could it be just a forgotten unmap? That would leave the old entry in the dma-debug list, but from the driver side it would be valid to map the same place again without corrupting any data transfer to the harddisk. What also would point in this direction, sometime I have seen this in my log: [ 1004.061989] DMA-API: debugging out of memory - disabling >> That could explain these warnings, if the hash_bucket >> returns a different entry that then has the wrong map/unmap count. >> >> So I added WARN_ON(hash_bucket_find(bucket, entry)); before the >> hash_bucket_add(bucket, entry); in add_dma_entry(); >> >> That WARN_ON() triggered more then 1500 times until the KDE desktop >> was loaded... > > > btw, does 'iommu=nomerge' kernel boot option fix the problem? No, this WARN_ON() still triggers and I just had another report from the debugging code: [ 1205.876238] sata_sil24 0000:04:00.0: DMA-API: device driver frees DMA sg list with different entry count [map count=13] [unmap count=1] Does it matter that the system in question is a 2 NUMA node system (using 2 Opteron CPUs)? Torsten >> This is the first full stackdump, I dont have the real first one, >> because the dmesg buffer overflowed. >> Jun 3 21:14:07 treogen [ 30.094954] ------------[ cut here ]------------ >> Jun 3 21:14:07 treogen [ 30.094960] WARNING: at lib/dma-debug.c:256 >> add_dma_entry+0x7b/0xb0() >> Jun 3 21:14:07 treogen [ 30.094964] Hardware name: KFN5-D SLI >> Jun 3 21:14:07 treogen [ 30.094966] Modules linked in: msp3400 >> tuner tea5767 tda8290 tuner_xc2028 xc >> 5000 tda9887 tuner_simple tuner_types mt20xx tea5761 bttv ir_common >> v4l2_common videodev v4l1_compat v4 >> l2_compat_ioctl32 videobuf_dma_sg videobuf_core sg btcx_risc pata_amd tveeprom >> Jun 3 21:14:07 treogen [ 30.094996] Pid: 1156, comm: md3_raid1 >> Tainted: G W 2.6.30-rc8 #3 >> Jun 3 21:14:07 treogen [ 30.094999] Call Trace: >> Jun 3 21:14:07 treogen [ 30.095005] [<ffffffff8041667b>] ? >> add_dma_entry+0x7b/0xb0 >> Jun 3 21:14:07 treogen [ 30.095012] [<ffffffff802432e8>] >> warn_slowpath_common+0x78/0xd0 >> Jun 3 21:14:07 treogen [ 30.095018] [<ffffffff8024334f>] >> warn_slowpath_null+0xf/0x20 >> Jun 3 21:14:07 treogen [ 30.095025] [<ffffffff8041667b>] >> add_dma_entry+0x7b/0xb0 >> Jun 3 21:14:07 treogen [ 30.095031] [<ffffffff80416db4>] >> debug_dma_map_sg+0x144/0x180 >> Jun 3 21:14:07 treogen [ 30.095038] [<ffffffff804d367c>] >> ata_qc_issue+0x19c/0x310 >> Jun 3 21:14:07 treogen [ 30.095044] [<ffffffff804bfca0>] ? >> scsi_done+0x0/0x20 >> Jun 3 21:14:07 treogen [ 30.095051] [<ffffffff804d92a0>] ? >> ata_scsi_rw_xlat+0x0/0x210 >> Jun 3 21:14:07 treogen [ 30.095058] [<ffffffff804d9558>] >> ata_scsi_translate+0xa8/0x180 >> Jun 3 21:14:07 treogen [ 30.095065] [<ffffffff804bfca0>] ? >> scsi_done+0x0/0x20 >> Jun 3 21:14:07 treogen [ 30.095070] [<ffffffff804dc0f1>] >> ata_scsi_queuecmd+0xb1/0x2d0 >> Jun 3 21:14:07 treogen [ 30.095077] [<ffffffff804bfda3>] >> scsi_dispatch_cmd+0xe3/0x220 >> Jun 3 21:14:07 treogen [ 30.095084] [<ffffffff804c5a0e>] >> scsi_request_fn+0x38e/0x480 >> Jun 3 21:14:07 treogen [ 30.095091] [<ffffffff803f0ae3>] >> __generic_unplug_device+0x33/0x40 >> Jun 3 21:14:07 treogen [ 30.095098] [<ffffffff803f0c09>] >> generic_unplug_device+0x29/0x40 >> Jun 3 21:14:07 treogen [ 30.095105] [<ffffffff803ef92e>] >> blk_unplug+0x4e/0x60 >> Jun 3 21:14:07 treogen [ 30.095111] [<ffffffff80566c7b>] >> unplug_slaves+0x9b/0xe0 >> Jun 3 21:14:07 treogen [ 30.095118] [<ffffffff80569418>] raid1d+0xd68/0x1070 >> Jun 3 21:14:07 treogen [ 30.095124] [<ffffffff8024dcea>] ? >> try_to_del_timer_sync+0x5a/0x70 >> Jun 3 21:14:07 treogen [ 30.095130] [<ffffffff8024dd1a>] ? >> del_timer_sync+0x1a/0x30 >> Jun 3 21:14:07 treogen [ 30.095138] [<ffffffff805708d4>] >> md_thread+0x54/0x140 >> Jun 3 21:14:07 treogen [ 30.095144] [<ffffffff80259cf0>] ? >> autoremove_wake_function+0x0/0x40 >> Jun 3 21:14:07 treogen [ 30.095151] [<ffffffff80570880>] ? >> md_thread+0x0/0x140 >> Jun 3 21:14:07 treogen [ 30.095158] [<ffffffff80570880>] ? >> md_thread+0x0/0x140 >> Jun 3 21:14:07 treogen [ 30.095164] [<ffffffff80259856>] kthread+0x56/0x90 >> Jun 3 21:14:07 treogen [ 30.095171] [<ffffffff8020c4aa>] child_rip+0xa/0x20 >> Jun 3 21:14:07 treogen [ 30.095178] [<ffffffff8020bea9>] ? >> restore_args+0x0/0x30 >> Jun 3 21:14:07 treogen [ 30.095184] [<ffffffff80259800>] ? kthread+0x0/0x90 >> Jun 3 21:14:07 treogen [ 30.095190] [<ffffffff8020c4a0>] ? >> child_rip+0x0/0x20 >> Jun 3 21:14:07 treogen [ 30.095194] ---[ end trace f87165562db78e9a ]--- >> >> Is this a bug in the DMA-API debuging or in libata / sata_sil24? >> >> Torsten >> >> >> DMA-API-Warning from vanilla 2.6.30-rc8: >> Jun 3 18:52:31 treogen [ 486.447661] ------------[ cut here ]------------ >> Jun 3 18:52:31 treogen [ 486.447684] WARNING: at lib/dma-debug.c:530 >> check_unmap+0x65e/0x6a0() >> Jun 3 18:52:31 treogen [ 486.447689] Hardware name: KFN5-D SLI >> Jun 3 18:52:31 treogen [ 486.447694] sata_sil24 0000:04:00.0: >> DMA-API: device driver frees DMA sg lis >> t with different entry count [map count=1] [unmap count=2] >> Jun 3 18:52:31 treogen [ 486.447699] Modules linked in: msp3400 >> tuner tea5767 tda8290 tuner_xc2028 xc >> 5000 tda9887 tuner_simple tuner_types mt20xx tea5761 bttv ir_common >> v4l2_common videodev v4l1_compat v4 >> l2_compat_ioctl32 videobuf_dma_sg videobuf_core pata_amd sg btcx_risc tveeprom >> Jun 3 18:52:31 treogen [ 486.447740] Pid: 3328, comm: nxproxy Not >> tainted 2.6.30-rc8 #1 >> Jun 3 18:52:31 treogen [ 486.447744] Call Trace: >> Jun 3 18:52:31 treogen [ 486.447748] <IRQ> [<ffffffff8041758e>] ? >> check_unmap+0x65e/0x6a0 >> Jun 3 18:52:31 treogen [ 486.447766] [<ffffffff802432e8>] >> warn_slowpath_common+0x78/0xd0 >> Jun 3 18:52:31 treogen [ 486.447773] [<ffffffff802433c4>] >> warn_slowpath_fmt+0x64/0x70 >> Jun 3 18:52:31 treogen [ 486.447783] [<ffffffff804d3665>] ? >> ata_qc_issue+0x1e5/0x300 >> Jun 3 18:52:31 treogen [ 486.447791] [<ffffffff804bfc70>] ? >> scsi_done+0x0/0x20 >> Jun 3 18:52:31 treogen [ 486.447799] [<ffffffff804d9260>] ? >> ata_scsi_rw_xlat+0x0/0x210 >> Jun 3 18:52:31 treogen [ 486.447807] [<ffffffff804d9518>] ? >> ata_scsi_translate+0xa8/0x180 >> Jun 3 18:52:31 treogen [ 486.447817] [<ffffffff8068d33d>] ? >> _spin_lock_irqsave+0x1d/0x40 >> Jun 3 18:52:31 treogen [ 486.447824] [<ffffffff8041758e>] >> check_unmap+0x65e/0x6a0 >> Jun 3 18:52:31 treogen [ 486.447831] [<ffffffff804176de>] >> debug_dma_unmap_sg+0x10e/0x1b0 >> Jun 3 18:52:31 treogen [ 486.447838] [<ffffffff804bff71>] ? >> __scsi_put_command+0x61/0xa0 >> Jun 3 18:52:31 treogen [ 486.447845] [<ffffffff804d30a8>] >> ata_sg_clean+0x78/0xf0 >> Jun 3 18:52:31 treogen [ 486.447852] [<ffffffff804d3155>] >> __ata_qc_complete+0x35/0x110 >> Jun 3 18:52:31 treogen [ 486.447862] [<ffffffff804c69d8>] ? >> scsi_io_completion+0x398/0x530 >> Jun 3 18:52:31 treogen [ 486.447869] [<ffffffff804d32ed>] >> ata_qc_complete+0xbd/0x250 >> Jun 3 18:52:31 treogen [ 486.447876] [<ffffffff804d382b>] >> ata_qc_complete_multiple+0xab/0xf0 >> Jun 3 18:52:31 treogen [ 486.447885] [<ffffffff804e90d9>] >> sil24_interrupt+0xb9/0x5b0 >> Jun 3 18:52:31 treogen [ 486.447894] [<ffffffff80273060>] >> handle_IRQ_event+0x70/0x180 >> Jun 3 18:52:31 treogen [ 486.447902] [<ffffffff8027536d>] >> handle_fasteoi_irq+0x6d/0xe0 >> Jun 3 18:52:31 treogen [ 486.447909] [<ffffffff8020e42f>] >> handle_irq+0x1f/0x30 >> Jun 3 18:52:31 treogen [ 486.447915] [<ffffffff8020db7a>] do_IRQ+0x6a/0xf0 >> Jun 3 18:52:31 treogen [ 486.447924] [<ffffffff8020be53>] >> ret_from_intr+0x0/0xf >> Jun 3 18:52:31 treogen [ 486.447927] <EOI> [<ffffffff802c967a>] ? >> file_move+0x3a/0x60 >> Jun 3 18:52:31 treogen [ 486.447939] [<ffffffff802c9668>] ? >> file_move+0x28/0x60 >> Jun 3 18:52:31 treogen [ 486.447949] [<ffffffff802c682f>] ? >> __dentry_open+0xbf/0x2e0 >> Jun 3 18:52:31 treogen [ 486.447957] [<ffffffff802c6b57>] ? >> nameidata_to_filp+0x57/0x70 >> Jun 3 18:52:31 treogen [ 486.447963] [<ffffffff802d51f2>] ? >> do_filp_open+0x292/0x990 >> Jun 3 18:52:31 treogen [ 486.447972] [<ffffffff8064915d>] ? >> unix_ioctl+0xad/0xf0 >> Jun 3 18:52:31 treogen [ 486.447979] [<ffffffff802bde9c>] ? >> get_partial_node+0x2c/0xa0 >> Jun 3 18:52:31 treogen [ 486.447986] [<ffffffff802c1705>] ? >> __slab_alloc+0x95/0x480 >> Jun 3 18:52:31 treogen [ 486.447992] [<ffffffff802d6b91>] ? >> vfs_ioctl+0x31/0xa0 >> Jun 3 18:52:31 treogen [ 486.447999] [<ffffffff8068a817>] ? >> thread_return+0x3e/0x6f7 >> Jun 3 18:52:31 treogen [ 486.448007] [<ffffffff802d25d6>] ? >> getname+0x36/0x200 >> Jun 3 18:52:31 treogen [ 486.448015] [<ffffffff802df56a>] ? >> alloc_fd+0x4a/0x140 >> Jun 3 18:52:31 treogen [ 486.448023] [<ffffffff802c668b>] ? >> do_sys_open+0x7b/0x110 >> Jun 3 18:52:31 treogen [ 486.448030] [<ffffffff802c674b>] ? >> sys_open+0x1b/0x20 >> Jun 3 18:52:31 treogen [ 486.448037] [<ffffffff8020b4eb>] ? >> system_call_fastpath+0x16/0x1b >> Jun 3 18:52:31 treogen [ 486.448042] ---[ end trace 9e90cc92d8410ab6 ]--- >> Jun 3 18:52:31 treogen [ 486.448045] Mapped at: >> Jun 3 18:52:31 treogen [ 486.448048] [<ffffffffffffffff>] 0xffffffffffffffff >> -- >> To unsubscribe from this list: 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 > -- To unsubscribe from this list: 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
