On 03/12/2014 06:36 AM, Mel Gorman wrote: > Andrew, this should go with the patches > mmnuma-reorganize-change_pmd_range.patch > mmnuma-reorganize-change_pmd_range-fix.patch > move-mmu-notifier-call-from-change_protection-to-change_pmd_range.patch > in mmotm please. > > Thanks.
That would be nice indeed :) I am still not entirely sure why the kernel did not hit this race before my reorganize change_pmd_range patch. Maybe gcc used to do one load and now it does two? > The problem is that a transhuge check is made without holding the PTL. It's > possible at the time of the check that a parallel fault clears the pmd > and inserts a new one which then triggers the VM_BUG_ON check. This patch > removes the VM_BUG_ON but fixes the race by rechecking transhuge under the > PTL when marking page tables for NUMA hinting and bailing if a race occurred. > It is not a problem for calls to mprotect() as they hold mmap_sem for write. > > Reported-by: Sasha Levin <[email protected]> > Signed-off-by: Mel Gorman <[email protected]> Reviewed-by: Rik van Riel <[email protected]> -- All rights reversed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
