I think we need to be careful, going forward, with these flush_tlb_page() removals in the initial commits.
On those cpus, each set_pte_at() call (and therefore indirectly via pte_clear()) queue up a per-cpu flush entry. Then, the various flush_tlb_*() calls don't flush a single entry but rather run the queue of pending TLB flushes. Therefore every single set_pte_at() call must have a subsequent flush_tlb_*() otherwise we'll return to userspace with stale entries in the per-cpu TLB flush queues. It seems to be the case that we turn out to be OK here, because __set_pte_at() on sparc64 as currently implemented does not queue up a TLB flush in the per-cpu queue if the PTE did not have the valid bit. And the default pte_accessible() returns true unconditionally. In fact is shows that we can probably can implement pte_accessible() to mirror the test done in __set_pte_at() and thus we'd get the optimization too on sparc64. But we really need to be careful about this, these kinds of bugs are hard to track down. Thanks. -- 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/
