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| author | Peter Zijlstra <peterz@infradead.org> | 2013-06-05 12:26:50 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-06-06 10:07:26 +0900 |
| commit | 29eb77825cc7da8d45b642de2de3d423dc8a363f (patch) | |
| tree | 689c3c9f8b34f8023899ba8c230ea04c4dc21e54 /mm/memory.c | |
| parent | 2c95523c0f0ca7c2f157a07f0c03b6bbba13fee6 (diff) | |
| download | op-kernel-dev-29eb77825cc7da8d45b642de2de3d423dc8a363f.zip op-kernel-dev-29eb77825cc7da8d45b642de2de3d423dc8a363f.tar.gz | |
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 <tglx@linutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Reported-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 9 |
1 files changed, 0 insertions, 9 deletions
diff --git a/mm/memory.c b/mm/memory.c index 6dc1882..61a262b 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) { |
