Messages in this thread | | | Date | Sat, 13 Oct 2007 08:19:17 -0400 | From | Jeff Garzik <> | Subject | Re: 2.6.23-mm1 |
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Torsten Kaiser wrote: > On 10/13/07, Jeff Garzik <jeff@garzik.org> wrote: >> Torsten Kaiser wrote: >>> On 10/12/07, Andrew Morton <akpm@linux-foundation.org> wrote: >>>> On Fri, 12 Oct 2007 10:31:42 +0200 "Torsten Kaiser" <just.for.lkml@googlemail.com> wrote: >>>>> Oct 12 10:23:03 treogen smartd[6091]: Device: /dev/sdc, not found in >>>>> smartd database. >>>> hm. >>>> >>>>> Oct 12 10:23:03 treogen [ 105.990000] WARNING: at >>>>> drivers/ata/libata-core.c:5752 ata_qc_issue() >>>> Let's cc linux-ide. >>>> >>>>> Oct 12 10:23:03 treogen [ 105.990000] >>>>> Oct 12 10:23:03 treogen [ 105.990000] Call Trace: >>>>> Oct 12 10:23:03 treogen [ 105.990000] [<ffffffff804442ef>] >>>>> ata_qc_issue+0x47f/0x540 >>>>> Oct 12 10:23:03 treogen [ 105.990000] [<ffffffff80432e60>] scsi_done+0x0/0x20 >>>>> Oct 12 10:23:03 treogen [ 105.990000] [<ffffffff80449c80>] >>>>> ata_scsi_flush_xlat+0x0/0x30 >>> Oct 13 07:46:48 treogen [ 99.850000] >>> Oct 13 07:46:48 treogen [ 99.850000] ata3: EH in SWNCQ >>> mode,QC:qc_active 0x3 sactive 0x1 >>> Oct 13 07:46:48 treogen [ 99.850000] ata3: SWNCQ:qc_active 0x1 >>> defer_bits 0x0 last_issue_tag 0x0 >> The WARNING indicates that there is a SWNCQ bug in sata_nv. Given that >> the problem appears when SYNCHRONIZE CACHE is being issued, I would > > I can't follow you on SYNCHRONIZE CACHE. > The only command written to the syslog in the errors where > 0x60==ATA_CMD_FPDMA_READ and 0xB0 (which is not in > include/linux/ata.h, but ATA-6 says that this is SMART related. That > makes sense, as smartd is failing).
In the traceback you have "ata_scsi_flush_xlat", which is the function that translates a SCSI sync-cache command into an ATA flush-cache command.
The "WARNING: at drivers/ata/libata-core.c:5752 ata_qc_issue()" also guides us to the code comment
/* Make sure only one non-NCQ command is outstanding. The * check is skipped for old EH because it reuses active qc to * request ATAPI sense. */
which is a check related to NCQ->off and off->NCQ edge cases.
So those are the two bits of information I found interesting.
>> guess that sata_nv is not properly handling non-queued commands. > > But that still seems correct, as I would not expect that SMART > commands get queued. (Thats just a guess, as I did not try to find the > code that does this distinction) > >> This is a patch from libata-dev.git#nv-swncq (via #ALL). > > Comparing sata_nv.c from 2.6.23-rc8-mm1 and 2.6.23-mm1 I see two > changes, that look suspicious: > > http://git.kernel.org/?p=linux/kernel/git/jgarzik/libata-dev.git;a=commitdiff;h=31cc23b34913bc173680bdc87af79e551bf8cc0d > > The comment says: "ahci and sata_sil24 are converted to use ata_std_qc_defer()." > But the patch also adds ".qc_defer = ata_std_qc_defer," to sata_nv.c > > The second change is the removal of the 'lock' spinlock from sata_nv.c > that was used in nv_swncq_qc_issue and nv_swncq_host_interrupt. > > Should I try to revert one or both of these changes?
If you are git-capable, IMO the next steps in problem elimination should be
* download latest linux-2.6.git (currently 752097cec53eea111d087c545179b421e2bde98a) * build and test linux-2.6.git, to establish a new baseline * download latest libata-dev.git#nv-swncq (currently 3cb664c2d319a4fde5028c3c5dab6221fe70bd2d) * build and test, with sata_nv module option swncq=0 * build and test, with sata_nv module option swncq=1
That will get -mm out of the picture, use the same baseline kernel for all three tests (nv-swncq is based off of 752097cec53eea111d087c545179b421e2bde98a) and narrow things down to the precise changes that went upstream (or are on the 'nv-swncq' branch, waiting to go upstream).
My gut feeling is that there is a lingering bug in sata_nv SWNCQ somewhere.
Jeff
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