Re: 2.6.24-rc8-mm1: powerpc oopses
From: Mariusz Kozlowski <hidden>
Date: 2008-01-18 17:23:22
Also in:
lkml
Hello,
quoted
Do we need `offset' at all?Looks like no. I wonder if there's a good argument for adding a pte_offset_val() which would let us do: pteval = pte_offset_val(pmd, addr); and shrink the map/unmap window and overhead here and possibly elsewhere? Anyway, updated but still untested patch now with revealing comment:
I patched the ppc32 kernel with this and run tests on /proc. This patch helps. No more BUGs and oopses :) Thanks, Mariusz
quoted hunk ↗ jump to hunk
diff -r 5595adaea70f fs/proc/task_mmu.c--- a/fs/proc/task_mmu.c Thu Jan 17 13:26:54 2008 -0600 +++ b/fs/proc/task_mmu.c Thu Jan 17 18:45:57 2008 -0600@@ -584,18 +585,19 @@ pte_t *pte; int err = 0; - pte = pte_offset_map(pmd, addr); - for (; addr != end; pte++, addr += PAGE_SIZE) { + for (; addr != end; addr += PAGE_SIZE) { u64 pfn = PM_NOT_PRESENT; + pte = pte_offset_map(pmd, addr); if (is_swap_pte(*pte)) pfn = swap_pte_to_pagemap_entry(*pte); else if (pte_present(*pte)) pfn = pte_pfn(*pte); + /* unmap so we're not in atomic when we copy to userspace */ + pte_unmap(pte); err = add_to_pagemap(addr, pfn, pm); if (err) return err; } - pte_unmap(pte - 1); cond_resched();