Hi,
I tried the patch that you pointed to and UP kernel boots fine. Looks
like that was a icache and dcache coherency problem now that there is no
flush_icache_page implementation.
The SMP kernel still has trouble.Turning on the first printk in fault.c
makes it work..which is interesting.
I added a __sb1_flush_icache_range call with dcache invalidation..still
no help. I don't see a SIGSEGV message now.The kernel hangs with no
response to keystrokes and the soft lockup detect error shows up after
sometime.
Oh, inserting flush_icache_page caused the kernel to panic. I also see
that __flush_icache_page is not used anywhere. Any future use?
Thx.
>-----Original Message-----
>From: Atsushi Nemoto [mailto:anemo@mba.ocn.ne.jp]
>Sent: Tuesday, September 26, 2006 2:40 AM
>To: Manoj Ekbote
>Cc: Mark E Mason; linux-mips@linux-mips.org;
>ralf@linux-mips.org; ths@networkno.de
>Subject: Re: [MIPS] SB1: Build fix: delete initialization of
>flush_icache_page pointer.
>
>On Mon, 25 Sep 2006 20:05:59 -0700, "Manoj Ekbote"
><manoje@broadcom.com> wrote:
>> The latest tip still has problems with booting on Broadcom boards.
>> I turned on a couple of printk's in the page fault handler and I see
>> the following messages:
>...
>> It looks like a cache corruption issue. Did the removal of
>> flush_icache_page cause this?
>
>Yes perhaps. But flush_icache_page() itself is obsolete API
>and should be gone (see Documentation/cachetlb.txt). So there
>should be fault in somewhere else.
>
>I think
>
>http://www.linux-mips.org/archives/linux-mips/2006-08/msg00184.html
>
>is still needed, but it seems not enough.
>
>If reverting flush_icache_page() worked, then you can debug more.
>
>1. kill part of local_sb1_flush_icache_page().
>
>If killing __sb1_writeback_inv_dcache_phys_range() part was
>OK, then it would be dcache issue, if killing
>drop_mmu_context() part was OK, then it would be icache issue.
>
>2. kill calls of flush_icache_page().
>
>If is used in only 3 places.
>
>mm/fremap.c: flush_icache_page(vma, page);
>mm/memory.c: flush_icache_page(vma, page);
>mm/memory.c: flush_icache_page(vma, new_page);
>
>Finding which lines are required might help further investigation.
>
>
>Another possible approach might be trying c-r4k.c instead of c-sb1.c.
>
>If you wanted to debug with latest git tree, note that
>include/asm-mips/hazard.h in current lmo git tree seems
>broken. The fix was already posted to this ML so hopefully we
>can see in git tree soon...
>
>---
>Atsushi Nemoto
>
>
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