> -----Original Message----- > From: linux-mips-bounce@xxxxxxxxxxxxxx > [mailto:linux-mips-bounce@xxxxxxxxxxxxxx] On Behalf Of Atsushi Nemoto > Sent: Wednesday, November 15, 2006 8:07 AM > To: Trevor Hamm > Cc: linux-mips@xxxxxxxxxxxxxx > Subject: Re: Problems booting Linux 2.6.18.1 on MIPS34K core > > Then, I can imagine three (hardly possible) case: > > A. PG_dcache_dirty bit was cleared accidently. > > B. The page is accessed by user process without page_mapping() > > C. kernel forgot to call update_mmu_cache() at somewhere. > > If case A, removing "&& Page_dcache_dirty(page)" condition from > __update_cache() will hide your problem. If case B, calling > flush_dcache_page() unconditionally in __update_cache() will hide your > problem. > > Anyway for now I can not see why this can happen... > Okay, so after writing up that long explanation, reading through some more kernel code, and re-reading what you wrote above, I realize that all I've done was to verify what you've already suspected all along -- that a flush_dcache_page on this page somehow doesn't flush the page. This is my first time studying the cache/memory management code in Linux 2.6; thanks for being so patient with me :-) I tried the remedies you suggested for Case A and B, but neither one produces a kernel which can boot from power-up. So far, the only work-around that works is calling flush_data_cache_page unconditionally from __flush_dcache_page. This would imply that Case C is the culprit. I'll see what I can do to verify this. Thanks, Trevor
