On Mon, 30 Sep 2013 09:52:59 +0100 Mel Gorman <mgorman@xxxxxxx> wrote: > On Fri, Sep 27, 2013 at 02:26:56PM +0100, Mel Gorman wrote: > > @@ -1732,9 +1732,9 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, > > entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); > > entry = pmd_mkhuge(entry); > > > > - page_add_new_anon_rmap(new_page, vma, haddr); > > - > > + pmdp_clear_flush(vma, address, pmd); > > set_pmd_at(mm, haddr, pmd, entry); > > + page_add_new_anon_rmap(new_page, vma, haddr); > > update_mmu_cache_pmd(vma, address, &entry); > > page_remove_rmap(page); > > /* > > pmdp_clear_flush should have used haddr Dang, we both discovered this over the weekend? :) In related news, it looks like update_mmu_cache_pmd should probably use haddr, too... ---- Subject: mm,numa: make THP migration mmu calls use haddr The THP NUMA migration function migrate_misplaced_transhuge_page makes several calls into the architecture specific MMU code. Those calls all expect the virtual address of the huge page boundary, not the fault address from somewhere inside the huge page. This fixes the below bug. [ 80.106362] kernel BUG at mm/pgtable-generic.c:103! ... [ 80.333720] Call Trace: [ 80.336450] [<ffffffff811d5f8b>] migrate_misplaced_transhuge_page+0x1eb/0x500 [ 80.344505] [<ffffffff811d8883>] do_huge_pmd_numa_page+0x1a3/0x330 [ 80.351497] [<ffffffff811a3cc5>] handle_mm_fault+0x285/0x370 [ 80.357898] [<ffffffff816d7df2>] __do_page_fault+0x172/0x5a0 [ 80.364307] [<ffffffff8137a3dd>] ? trace_hardirqs_off_thunk+0x3a/0x3c [ 80.371585] [<ffffffff816d822e>] do_page_fault+0xe/0x10 [ 80.377510] [<ffffffff816d41c8>] page_fault+0x28/0x30 Signed-off-by: Rik van Riel <riel@xxxxxxxxxx> Reported-by: Jan Stancek <jstancek@xxxxxxxxxx> Tested-by: Jan Stancek <jstancek@xxxxxxxxxx> --- mm/migrate.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 1e1dbc9..5454151 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1736,10 +1736,10 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); entry = pmd_mkhuge(entry); - pmdp_clear_flush(vma, address, pmd); + pmdp_clear_flush(vma, haddr, pmd); set_pmd_at(mm, haddr, pmd, entry); page_add_new_anon_rmap(new_page, vma, haddr); - update_mmu_cache_pmd(vma, address, &entry); + update_mmu_cache_pmd(vma, haddr, &entry); page_remove_rmap(page); /* * Finish the charge transaction under the page table lock to -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>