On Wed, 22 Aug 2012, Andi Kleen wrote: > Andrea Arcangeli <aarca...@redhat.com> writes: > > + /* > > + * Take the lock with irqs disabled to avoid a lock > > + * inversion with the lru_lock. The lru_lock is taken > > + * before the autonuma_migrate_lock in > > + * split_huge_page. If we didn't disable irqs, the > > + * lru_lock could be taken by interrupts after we have > > + * obtained the autonuma_migrate_lock here. > > + */ > > Which interrupt code takes the lru_lock? That sounds like a bug.
Not a bug: the clearest example is end_page_writeback() calling rotate_reclaimable_page(); but I think once you probe deeper, you find some other mm/swap.c pagevec operations which may get called from interrupt, and end up freeing unrelated PageLRU pages. Hugh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
