Re: [bisected] 5.12-rc1 hpsa regression: "scsi: hpsa: Correct dev cmds outstanding for retried cmds"

Geert Uytterhoeven
2021-03-05T09:22:20Z

Hi Don,

On Fri, Mar 5, 2021 at 12:26 AM <Don.Brace@microchip.com> wrote:
> -----Original Message-----
> From: Sergei Trofimovich [mailto:slyich@gmail.com]
> Sent: Wednesday, March 3, 2021 2:56 AM
> To: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>; Don Brace - C33706 <Don.Brace@microchip.com>; storagedev <storagedev@microchip.com>; linux-scsi@vger.kernel.org
> Cc: linux-ia64@vger.kernel.org; linux-kernel@vger.kernel.org; Joe Szczypek <jszczype@redhat.com>; Scott Benesh - C33703 <Scott.Benesh@microchip.com>; Scott Teel - C33730 <Scott.Teel@microchip.com>; Tomas Henzl <thenzl@redhat.com>; Martin K. Petersen <martin.petersen@oracle.com>
> Subject: Re: [bisected] 5.12-rc1 hpsa regression: "scsi: hpsa: Correct dev cmds outstanding for retried cmds" breaks hpsa P600
>
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> On Wed, 3 Mar 2021 00:22:36 +0000
> Sergei Trofimovich <slyich@gmail.com> wrote:
>
> > On Tue, 2 Mar 2021 23:31:32 +0100
> > John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> wrote:
> >
> > > Hi Sergei!
> > >
> > > On 3/2/21 11:26 PM, Sergei Trofimovich wrote:
> > > > Gave v5.12-rc1 a try today and got a similar boot failure around
> > > > hpsa queue initialization, but my failure is later:
> > > > https://dev.gentoo.org/~slyfox/configs/guppy-dmesg-5.12-rc1
> > > > Maybe I get different error because I flipped on most debugging
> > > > kernel options :)
> > > >
> > > > Looks like 'ERROR: Invalid distance value range' while being very
> > > > scary are harmless. It's just a new spammy way for kernel to
> > > > report lack of NUMA config on the machine (no SRAT and SLIT ACPI
> > > > tables).
> > > >
> > > > At least I get hpsa detected on PCI bus. But I guess it's
> > > > discovered configuration is very wrong as I get unaligned accesses:
> > > > [ 19.811570] kernel unaligned access to 0xe000000105dd8295, ip=0xa000000100b874d1
>
> Running pahole before the patch:
>
> struct CommandList {
> struct CommandListHeader Header; /* 0 20 */
> struct RequestBlock Request; /* 20 20 */
> struct ErrDescriptor ErrDesc; /* 40 12 */
> struct SGDescriptor SG[32]; /* 52 512 */
> /* --- cacheline 8 boundary (512 bytes) was 52 bytes ago --- */
> u32 busaddr; /* 564 4 */
> struct ErrorInfo * err_info; /* 568 8 */
> /* --- cacheline 9 boundary (576 bytes) --- */
> struct ctlr_info * h; /* 576 8 */
> int cmd_type; /* 584 4 */
> long int cmdindex; /* 588 8 */
> struct completion * waiting; /* 596 8 */
> struct scsi_cmnd * scsi_cmd; /* 604 8 */
> struct work_struct work; /* 612 32 */
> /* --- cacheline 10 boundary (640 bytes) was 4 bytes ago --- */
> struct hpsa_scsi_dev_t * phys_disk; /* 644 8 */
> int abort_pending; /* 652 4 */
> struct hpsa_scsi_dev_t * device; /* 656 8 */
> atomic_t refcount; /* 664 4 */
>
> /* size: 768, cachelines: 12, members: 16 */
> /* padding: 100 */
> } __attribute__((__aligned__(128)));
>
> Pahole after the patch:
>
> struct CommandList {
> struct CommandListHeader Header; /* 0 20 */
> struct RequestBlock Request; /* 20 20 */
> struct ErrDescriptor ErrDesc; /* 40 12 */
> struct SGDescriptor SG[32]; /* 52 512 */
> /* --- cacheline 8 boundary (512 bytes) was 52 bytes ago --- */
> u32 busaddr; /* 564 4 */
> struct ErrorInfo * err_info; /* 568 8 */
> /* --- cacheline 9 boundary (576 bytes) --- */
> struct ctlr_info * h; /* 576 8 */
> int cmd_type; /* 584 4 */
> long int cmdindex; /* 588 8 */
> struct completion * waiting; /* 596 8 */
> struct scsi_cmnd * scsi_cmd; /* 604 8 */
> struct work_struct work; /* 612 32 */
> /* --- cacheline 10 boundary (640 bytes) was 4 bytes ago --- */
> struct hpsa_scsi_dev_t * phys_disk; /* 644 8 */
> struct hpsa_scsi_dev_t * device; /* 652 8 */
> bool retry_pending; /* 660 1 */
> atomic_t refcount; /* 661 4 */

How come this atomic_t is no longer aligned to its natural alignment?

>
> /* size: 768, cachelines: 12, members: 16 */
> /* padding: 103 */
> } __attribute__((__aligned__(128)));

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds