From 29eb77825cc7da8d45b642de2de3d423dc8a363f Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 5 Jun 2013 12:26:50 +0200 Subject: arch, mm: Remove tlb_fast_mode() Since the introduction of preemptible mmu_gather TLB fast mode has been broken. TLB fast mode relies on there being absolutely no concurrency; it frees pages first and invalidates TLBs later. However now we can get concurrency and stuff goes *bang*. This patch removes all tlb_fast_mode() code; it was found the better option vs trying to patch the hole by entangling tlb invalidation with the scheduler. Cc: Thomas Gleixner Cc: Russell King Cc: Tony Luck Reported-by: Max Filippov Signed-off-by: Peter Zijlstra Signed-off-by: Linus Torvalds --- mm/memory.c | 9 --------- 1 file changed, 9 deletions(-) (limited to 'mm') diff --git a/mm/memory.c b/mm/memory.c index 6dc1882fbd72..61a262b08e53 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -220,7 +220,6 @@ void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm) tlb->start = -1UL; tlb->end = 0; tlb->need_flush = 0; - tlb->fast_mode = (num_possible_cpus() == 1); tlb->local.next = NULL; tlb->local.nr = 0; tlb->local.max = ARRAY_SIZE(tlb->__pages); @@ -244,9 +243,6 @@ void tlb_flush_mmu(struct mmu_gather *tlb) tlb_table_flush(tlb); #endif - if (tlb_fast_mode(tlb)) - return; - for (batch = &tlb->local; batch; batch = batch->next) { free_pages_and_swap_cache(batch->pages, batch->nr); batch->nr = 0; @@ -288,11 +284,6 @@ int __tlb_remove_page(struct mmu_gather *tlb, struct page *page) VM_BUG_ON(!tlb->need_flush); - if (tlb_fast_mode(tlb)) { - free_page_and_swap_cache(page); - return 1; /* avoid calling tlb_flush_mmu() */ - } - batch = tlb->active; batch->pages[batch->nr++] = page; if (batch->nr == batch->max) { -- cgit v1.2.3