Re: 2.5.55/.56 instant reboot problem on 486

From: Bill Davidsen (davidsen@tmr.com)
Date: Sun Jan 12 2003 - 23:20:04 EST


On Sun, 12 Jan 2003, Brian Gerst wrote:

> The problem is that one_page_table_init() pulls the rug out from under
> the kernel by installing a new page table before setting it up. A 486
> has a small TLB so any miss will cause a triple fault and reset. Try
> this patch and see if it fixes it.

As someone who uses 486's for routers on occasion, thank you!

-- 
bill davidsen <davidsen@tmr.com>
  CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.

diff -urN linux-2.5.56/arch/i386/mm/init.c linux/arch/i386/mm/init.c --- linux-2.5.56/arch/i386/mm/init.c Sun Jan 12 00:16:22 2003 +++ linux/arch/i386/mm/init.c Sun Jan 12 01:48:28 2003 @@ -71,12 +71,16 @@ */ static pte_t * __init one_page_table_init(pmd_t *pmd) { - pte_t *page_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); - set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); - if (page_table != pte_offset_kernel(pmd, 0)) - BUG(); + if (pmd_none(*pmd)) { + pte_t *page_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); + set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); + if (page_table != pte_offset_kernel(pmd, 0)) + BUG(); - return page_table; + return page_table; + } + + return pte_offset_kernel(pmd, 0); } /*

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Wed Jan 15 2003 - 22:00:43 EST