[Linux-ia64] Patch to fix latest kernels issue with FW83

[Linux-ia64] Patch to fix latest kernels issue with FW83

[Mallick, Asit K]

[-- Attachment #1: Type: text/plain, Size: 750 bytes --]

We have root caused the stability problem with latest kernels and FW83 (LION
platform). The following patch (based on 2.4.17) fixes the problem. Please
let me know if you still see a problem after applying this patch.

Thanks,
Asit
 <<patch.FW83>> 
--- /home1/src/linux/include/asm-ia64/spinlock.h    Wed Jan  9 19:25:05 2002
+++ linux/include/asm-ia64/spinlock.h   Wed Jan 23 15:52:45 2002
@@ -84,7 +84,7 @@
    "mov r29 = 1\n"                     \
    ";;\n"                          \
    "1:\n"                          \
-   "ld4.bias r2 = [%0]\n"                  \
+   "ld4 r2 = [%0]\n"                   \
    ";;\n"                          \
    "cmp4.eq p0,p7 = r0,r2\n"               \
    "(p7) br.cond.spnt.few 1b \n"               \


[-- Attachment #2: patch.FW83 --]
[-- Type: application/octet-stream, Size: 358 bytes --]

--- /home1/src/linux/include/asm-ia64/spinlock.h	Wed Jan  9 19:25:05 2002
+++ linux/include/asm-ia64/spinlock.h	Wed Jan 23 15:52:45 2002
@@ -84,7 +84,7 @@
 	"mov r29 = 1\n"						\
 	";;\n"							\
 	"1:\n"							\
-	"ld4.bias r2 = [%0]\n"					\
+	"ld4 r2 = [%0]\n"					\
 	";;\n"							\
 	"cmp4.eq p0,p7 = r0,r2\n"				\
 	"(p7) br.cond.spnt.few 1b \n"				\

Re: [Linux-ia64] Patch to fix latest kernels issue with FW83

[Andreas Schwab]

"Mallick, Asit K" <asit.k.mallick@intel.com> writes:

|> We have root caused the stability problem with latest kernels and FW83 (LION
|> platform). The following patch (based on 2.4.17) fixes the problem. Please
|> let me know if you still see a problem after applying this patch.

I'm getting an infinite stream of "ia64_log_get: Failed to retrieve
SAL error record type 3", rendering the machine useless.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE GmbH, Deutschherrnstr. 15-19, D-90429 Nürnberg
Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: [Linux-ia64] Patch to fix latest kernels issue with FW83

[Bjorn Helgaas]

On Thursday 24 January 2002 12:46 pm, Mallick, Asit K wrote:
> We have root caused the stability problem with latest kernels and FW83
> (LION platform). The following patch (based on 2.4.17) fixes the
> problem.
...
> -   "ld4.bias r2 = [%0]\n"                  \
> +   "ld4 r2 = [%0]\n"                   \

Can you elaborate on this a bit?  All I know about ld.bias is the statement
in section 4.4.6.1 of Vol 1 that

    [ld.bias] is a hint to the implementation to acquire exclusive
    ownership of the line containing the addressed data.  The bias
    hint does not affect program functionality and may be ignored
    by the implementation.

I can believe the patch is a performance optimization (my intuition is that
when the holder writes the lock to release it, the waiter will merely
invalidate its shared line, where it previously had to invalidate and
copyout its exclusive line), but I don't see how this should improve
stability.  What am I missing?
-- 
Bjorn Helgaas - bjorn_helgaas@hp.com
Linux Systems Operation R&D
Hewlett-Packard

RE: [Linux-ia64] Patch to fix latest kernels issue with FW83

[Hall, Jenna S]

This is yet another symptom of running old firmware.  To avoid this, turn of
"Enable IA-64 Machine Check Abort" under General Setup in your config.

In short, the older firmware releases contain MCA support that is either
broken or nonexistent.  In this case the firmware is falsely reporting
corrected platform errors to the OS, in an endless stream that debilitates
the OS if OS MCA reporting is enabled.

Jenna

-----Original Message-----
From: Andreas Schwab [mailto:schwab@suse.de]
Sent: Friday, January 25, 2002 7:12 AM
To: Mallick, Asit K
Cc: linux-ia64@linuxia64.org
Subject: Re: [Linux-ia64] Patch to fix latest kernels issue with FW83

"Mallick, Asit K" <asit.k.mallick@intel.com> writes:

|> We have root caused the stability problem with latest kernels and FW83
(LION
|> platform). The following patch (based on 2.4.17) fixes the problem.
Please
|> let me know if you still see a problem after applying this patch.

I'm getting an infinite stream of "ia64_log_get: Failed to retrieve
SAL error record type 3", rendering the machine useless.

Andreas.

--
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE GmbH, Deutschherrnstr. 15-19, D-90429 Nürnberg
Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

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RE: [Linux-ia64] Patch to fix latest kernels issue with FW83

[Mallick, Asit K]

> -----Original Message-----
> From: Bjorn Helgaas [mailto:bjorn_helgaas@hp.com]
> Sent: Friday, January 25, 2002 8:08 AM
> To: Mallick, Asit K; linux-ia64@linuxia64.org
> Subject: Re: [Linux-ia64] Patch to fix latest kernels issue with FW83
> 
> 
> On Thursday 24 January 2002 12:46 pm, Mallick, Asit K wrote:
> > We have root caused the stability problem with latest 
> kernels and FW83
> > (LION platform). The following patch (based on 2.4.17) fixes the
> > problem.
> ...
> > -   "ld4.bias r2 = [%0]\n"                  \
> > +   "ld4 r2 = [%0]\n"                   \
> 
> Can you elaborate on this a bit?  All I know about ld.bias is 
> the statement
> in section 4.4.6.1 of Vol 1 that
> 
>     [ld.bias] is a hint to the implementation to acquire exclusive
>     ownership of the line containing the addressed data.  The bias
>     hint does not affect program functionality and may be ignored
>     by the implementation.

This is correcnt.

> 
> I can believe the patch is a performance optimization (my 
> intuition is that
> when the holder writes the lock to release it, the waiter will merely
> invalidate its shared line, where it previously had to invalidate and
> copyout its exclusive line), but I don't see how this should improve
> stability.  What am I missing?

FW83 does not have a workaround for a chipset issue (chipset SAC errata#2 in
460GX specification update) that could cause a livelock with ld.bias loops
and no modification. The later version of the FWs have the workaround and
will not see this problem.


Thanks,
Asit