Messages in this thread | | | Date | Mon, 3 Mar 2008 18:40:09 +0100 | From | Ingo Molnar <> | Subject | Re: bisected boot regression post 2.6.25-rc3.. please revert |
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* Arjan van de Ven <arjan@linux.intel.com> wrote:
> ------------[ cut here ]------------ > WARNING: at arch/x86/mm/pgtable_32.c:387 pmd_bad+0x44/0x53() > Modules linked in: > Pid: 1, comm: swapper Not tainted 2.6.25-rc3 #14 > [<c0424ba5>] warn_on_slowpath+0x41/0x67 > [<c0408c5c>] ? native_sched_clock+0x94/0xa6 > [<c043f432>] ? lock_release_holdtime+0x1a/0x115 > [<c04702d4>] ? handle_mm_fault+0x297/0x7e2 > [<c063eee6>] ? _spin_unlock+0x1d/0x20 > [<c04707f0>] ? handle_mm_fault+0x7b3/0x7e2 > [<c04851c1>] ? do_sync_read+0xab/0xe9 > [<c0417223>] pmd_bad+0x44/0x53 > [<c046f37f>] follow_page+0x8b/0x1f2 > [<c0470aa0>] get_user_pages+0x281/0x2ef
hm. I suspect some gcc related difference related to the handling of this masking:
pmd_val(x) & ~(PAGE_MASK | _PAGE_USER | _PAGE_PSE | _PAGE_NX)
versus:
pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)
perhaps it will work if you change it to:
pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER & ~_PAGE_PSE & ~_PAGE_NX)
?
in any case, the commit has to be reverted as it clearly isnt a NOP on your box as it was intended to be. (it should only have made a difference in a rare hugetlbfs case)
Ingo
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