Re: 2.6.17-rc5-mm1

[Roland Dreier <rdreier@cisco.com>]

I'm seeing problems with MSI-X interrupts on 2.6.17-rc5-mm1.  I'll try
to debug the MSI patches in -mm further in the next day or so, but for
now I'll post the symptoms.

When I load the ib_mthca driver with MSI-X interrupts enabled, I get
the following crash as soon as the first interrupt is generated.

[  329.979089] Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP:
[  329.995487]  [<0000000000000000>]
<8>[  330.012818] PGD 119477067 PUD 119b48067 PMD 0
[  330.027009] Oops: 0010 [1] SMP
[  330.036503] last sysfs file: /class/net/ib2/address
<8>[  330.051084] CPU 0
<8>[  330.057932] Modules linked in: ib_mthca ib_srp ib_cm ib_ipoib ib_sa ib_mad ib_core nfs lockd nfs_acl sunrpc ipv6 thermal fan button processor ac battery dm_mod ide_generic ide_disk evdev usbhid ide_cd cdrom amd74xx psmouse serio_raw e1000 pcspkr generic ohci_hcd ehci_hcd ide_core
<8>[  330.134158] Pid: 0, comm: idle Not tainted 2.6.17-rc5-mm1 #7
<8>[  330.151851] RIP: 0010:[<0000000000000000>]  [<0000000000000000>]
<8>[  330.170116] RSP: 0000:ffffffff805d4f98  EFLAGS: 00010016
<8>[  330.187344] RAX: 0000000000005200 RBX: ffffffff80873eb8 RCX: 0000000000000000
<8>[  330.209448] RDX: ffffffff80873eb8 RSI: ffffffff80863e80 RDI: 0000000000000052
<8>[  330.231552] RBP: ffffffff805d4fb0 R08: 0000000000000001 R09: ffffffff804380f7
<8>[  330.253656] R10: ffff81007adc6000 R11: 0000000000000000 R12: 0000000000000052
<8>[  330.275762] R13: 0000000000090000 R14: 0000000000000000 R15: 0000000000000000
<8>[  330.297867] FS:  00002b9e555966d0(0000) GS:ffffffff8085c000(0000) knlGS:0000000000000000
<8>[  330.322823] CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
<8>[  330.340777] CR2: 0000000000000000 CR3: 0000000119bd7000 CR4: 00000000000006e0
<8>[  330.362882] Process idle (pid: 0, threadinfo ffffffff80872000, task ffffffff804baa00)
<8>[  330.387061] Stack: ffffffff8020c693 ffffffff80207c93 0000000000000100 ffffffff80873ee0
<8>[  330.411423]        ffffffff80209b89  <EOI> ff6500230f54e8fa 65c900000020250c 00000010250c8b48
<8>[  330.438222]        f700001fd8e98148 7400000003582444
<8>[  330.454231] Call Trace:
<8>[  330.462870]  <IRQ> [<ffffffff8020c693>] do_IRQ+0x5e/0x6f
<8>[  330.479631]  [<ffffffff80207c93>] default_idle+0x0/0x9b
<8>[  330.496080]  [<ffffffff80209b89>] ret_from_intr+0x0/0xf
<8>[  330.512526]  <EOI>Unable to handle kernel paging request at ffffffff82800000 RIP:
[  332.136320]  [<ffffffff8020ad6e>] show_trace+0x145/0x195
<8>[  332.159591] PGD 203027 PUD 205027 PMD 0
[  332.172226] Oops: 0000 [2] SMP
[  332.181720] last sysfs file: /class/net/ib2/address
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