Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754122AbYKSR2V (ORCPT ); Wed, 19 Nov 2008 12:28:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752391AbYKSR2J (ORCPT ); Wed, 19 Nov 2008 12:28:09 -0500 Received: from g5t0006.atlanta.hp.com ([15.192.0.43]:26305 "EHLO g5t0006.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751964AbYKSR2I convert rfc822-to-8bit (ORCPT ); Wed, 19 Nov 2008 12:28:08 -0500 From: "Miller, Mike (OS Dev)" To: Randy Dunlap CC: Jens Axboe , scsi , James Bottomley , lkml , akpm Date: Wed, 19 Nov 2008 17:27:18 +0000 Subject: RE: in 2.6.23-rc3-git7 in do_cciss_intr Thread-Topic: in 2.6.23-rc3-git7 in do_cciss_intr Thread-Index: AclKa3oDV7q3ch15Q+eHWOcqMStEfgAAFmIA Message-ID: <0F5B06BAB751E047AB5C87D1F77A77884EACB798C4@GVW0547EXC.americas.hpqcorp.net> References: <0F5B06BAB751E047AB5C87D1F77A77883511810894@GVW0547EXC.americas.hpqcorp.net> <48C013D9.7060309@oracle.com> <0F5B06BAB751E047AB5C87D1F77A7788413663D229@GVW0547EXC.americas.hpqcorp.net> <20080905092838.GS20055@kernel.dk> <48DBF583.3050307@oracle.com> <20080925134000.9b133f8c.randy.dunlap@oracle.com> <0F5B06BAB751E047AB5C87D1F77A77884BFF5D1F76@GVW0547EXC.americas.hpqcorp.net> <49232232.10604@oracle.com> <4923237B.9090707@xenotime.net> <4923347D.8000205@oracle.com> <20081119085227.GQ26308@kernel.dk> <0F5B06BAB751E047AB5C87D1F77A77884EACB7986A@GVW0547EXC.americas.hpqcorp.net> <49244B69.80903@oracle.com> In-Reply-To: <49244B69.80903@oracle.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7519 Lines: 211 > -----Original Message----- > From: Randy Dunlap [mailto:randy.dunlap@oracle.com] > Sent: Wednesday, November 19, 2008 11:23 AM > To: Miller, Mike (OS Dev) > Cc: Jens Axboe; scsi; James Bottomley; lkml; akpm > Subject: Re: in 2.6.23-rc3-git7 in do_cciss_intr > > Miller, Mike (OS Dev) wrote: > > > >> -----Original Message----- > >> From: Jens Axboe [mailto:jens.axboe@oracle.com] > >> Sent: Wednesday, November 19, 2008 2:52 AM > >> To: Randy Dunlap > >> Cc: scsi; Miller, Mike (OS Dev); James Bottomley; lkml; akpm > >> Subject: Re: in 2.6.23-rc3-git7 in do_cciss_intr > >> > >> On Tue, Nov 18 2008, Randy Dunlap wrote: > >>> Randy Dunlap wrote: > >>>> Randy Dunlap wrote: > >>>>> Miller, Mike (OS Dev) wrote: > >>>>>>> -----Original Message----- > >>>>>>> From: Randy Dunlap [mailto:randy.dunlap@oracle.com] > >>>>>>> Sent: Thursday, September 25, 2008 3:40 PM > >>>>>>> To: scsi > >>>>>>> Cc: Jens Axboe; Miller, Mike (OS Dev); James Bottomley; lkml; > >>>>>>> akpm > >>>>>>> Subject: Re: in 2.6.23-rc3-git7 in do_cciss_intr > >>>>>>> > >>>>>>> On Thu, 25 Sep 2008 13:33:07 -0700 Randy Dunlap wrote: > >>>>>>> > >>>>>>>> Jens Axboe wrote: > >>>>>>>>> On Thu, Sep 04 2008, Miller, Mike (OS Dev) wrote: > >>>>>>>>>>>>>> 0x3bb2 : mov 0x2(%r8),%dx > >>>>>>>>>>>>>> 0x3bb7 : test %dx,%dx > >>>>>>>>>>>>>> 0x3bba : je 0x3f0e > >>>>>>> > >>>>>>>>>>>>>> $ addr2line -e cciss.o -f do_cciss_intr+0x627 > >>>>>>>>>>>>>> SA5_fifo_full > >>>>>>>>>>>>>> > >> /home/rdunlap/linsrc/linux-2.6.27-rc3-git7/drivers/block/cciss.h: > >>>>>>> 2 > >>>>>>>>>>> 06 > >>>>>>>>>>>>> OK ...that's confusing. It seems to be saying that > >>>>>>> ctrlr_info_t > >>>>>>>>>>>>> * was NULL. However, I can't see a way of > >> getting into the > >>>>>>>>>>> fifo_full > >>>>>>>>>>>>> callback from do_cciss_intr .. > >>>>>>>>>>>>> especially not with an NULL host. > >>>>>>>>>>>>> > >>>>>>>>>>>>> James > >>>>>>>>>>>> That is weird. Even if we could get there > >> fifo_full doesn't > >>>>>>>>>>> do anything but wait for a bit. > >>>>>>>>>>> > >>>>>>>>>>> Hi, > >>>>>>>>>>> > >>>>>>>>>>> This just happened again. This time it's on > >> 2.6.27-rc5-git3. > >>>>>>>>>>> ~Randy > >>>>>>>>>> Thanks Randy. I think. :) > >>>>>>>>>> > >>>>>>>>>> I'll try to recreate in my lab. > >>>>>>>>> This looks somewhat strange, mostly like 'c' is NULL > >> and it's > >>>>>>>>> oopsing in in removeQ (I don't think Randy's analysis is > >>>>>>> correct in > >>>>>>>>> assuming it's 'h' and it's in fifo_full). Given that 'c' > >>>>>>> cannot be > >>>>>>>>> NULL, it's c->prev or c->next that are NULL. > >>>>> This BUG: has happened (now) 5 times today. Higher > >> frequency than > >>>>> usual for some reason. > >>>>> > >>>>> I enabled CCISS_DEBUG and added one printk in > removeQ(). On the > >>>>> first call > >>>> s/first/second/ > >>>> > >>>> > >>>>> to removeQ(), both c->next and c->prev are NULL. > >>>>> > >>>>> Here's the kernel log output from cciss: > >>> I added a printk() in addQ() as well. Here's the new output: > >>> > >>> HP CISS Driver (v 3.6.20) > >>> ACPI: PCI Interrupt Link [LNKA] enabled at IRQ 54 cciss > >> 0000:42:08.0: > >>> PCI INT A -> Link[LNKA] -> GSI 54 (level, high) -> IRQ 54 > command = > >>> 147 irq = 36 board_id = 3211103c cciss 0000:42:08.0: irq 87 for > >>> MSI/MSI-X address 0 = fdf80000 cfg base address = 10 cfg > >> base address > >>> index = 0 cfg offset = 400 Controller Configuration information > >>> ------------------------------------ > >>> Signature = CISS > >>> Spec Number = 1 > >>> Transport methods supported = 0x6 > >>> Transport methods active = 0x3 > >>> Requested transport Method = 0x0 > >>> Coalesce Interrupt Delay = 0x0 > >>> Coalesce Interrupt Count = 0x1 > >>> Max outstanding commands = 0x256 > >>> Bus Types = 0x200000 > >>> Server Name = > >>> Heartbeat Counter = 0x1672 > >>> > >>> > >>> Trying to put board into Simple mode I counter got to 1 0 > Controller > >>> Configuration information > >>> ------------------------------------ > >>> Signature = CISS > >>> Spec Number = 1 > >>> Transport methods supported = 0x6 > >>> Transport methods active = 0x3 > >>> Requested transport Method = 0x0 > >>> Coalesce Interrupt Delay = 0x0 > >>> Coalesce Interrupt Count = 0x1 > >>> Max outstanding commands = 0x256 > >>> Bus Types = 0x200000 > >>> Server Name = > >>> Heartbeat Counter = 0x1672 > >>> > >>> > >>> cciss0: <0x3238> at PCI 0000:42:08.0 IRQ 87 using DAC > >>> cciss: intr_pending 8 > >>> cciss: addQ: Qptr=ffff88027e0100b8, c=ffff88007f83e000 > >>> cciss: removeQ: Qptr=ffff88027e0100b8, c=ffff88007f83e000, > >>> next=ffff88007f83e000, prev=ffff88007f83e000 Sending > >> 7f83e000 - down > >>> to controller > >>> cciss: addQ: Qptr=ffff88027e0100c0, c=ffff88007f83e000 > >>> cciss: intr_pending 8 > >>> cciss: Read 4 back from board > >>> cciss: removeQ: Qptr=ffff88027e0100c0, c=ffff88007f840000, > >>> next=0000000000000000, prev=0000000000000000 > >>> BUG: unable to handle kernel NULL pointer dereference at > >>> 0000000000000248 > >> Randy, can you post the debug patch you used? The above goes boom > >> when it attempts to remove a command that isn't on the > list, the Qptr > >> in the last example should be empty, hence the oops. So I'd be > >> interested in seeing what removeQ() calls this is, I'm > assuming it's > >> this bit in > >> do_cciss_intr(): > >> > >> ... > >> while (c->busaddr != a) { > >> c = c->next; > >> if (c == h->cmpQ) > >> break; > >> } > >> } > >> /* > >> * If we've found the command, take it off the > >> * completion Q and free it > >> */ > >> if (c->busaddr == a) { > >> removeQ(&h->cmpQ, c); > >> if (c->cmd_type == CMD_RWREQ) { > >> complete_command(h, c, 0); > >> ... > >> > >> If so, what part of the c lookup are you hitting - the on > that does: > >> > >> c = h->cmd_pool + a2; > >> > >> or the c->busaddr check that his shown above? > >> > >> -- > > Randy, > > I still can't reproduce this bug. I have your config file > on a BL465c w/e200i. Just to confirm, you only see this at > init time, correct? > > Yes, only at init time. > > > Please post your debug patch as Jens requested. > > Done (separately). > > I need to back up a bit. Yesterday these BUGs happened > consistenly, so I wondered why. Then I recalled that for > debugging another bug/problem, I had changed the test > system's normal boot kernel from 2.6.25 to 2.6.18-8. The > test system is used to build and then boot the new kernel > *via kexec*, so it's quite possible (or certain) that > something in the kexec world has been fixed since 2.6.18. I > don't recall seeing this problem lately when using 2.6.25 to > kexec/boot the new test kernel, so I'm quite willing to drop > the bug for now and then re-open it if I see the problem again. OK?? Ahhhh, the kexec piece was missing. Now I don't feel quite so clueless. I'm OK with dropping the bug for now. Jens, James? -- mikem > > -- > ~Randy > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/