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>
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index b1b1fa6..13821c3 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -97,11 +97,9 @@
unsigned long start;
unsigned long end;
unsigned int need_flush : 1, /* Did free PTEs */
- fast_mode : 1; /* No batching */
-
/* we are in the middle of an operation to clear
* a full mm and can make some optimizations */
- unsigned int fullmm : 1,
+ fullmm : 1,
/* we have performed an operation which
* requires a complete flush of the tlb */
need_flush_all : 1;
@@ -114,19 +112,6 @@
#define HAVE_GENERIC_MMU_GATHER
-static inline int tlb_fast_mode(struct mmu_gather *tlb)
-{
-#ifdef CONFIG_SMP
- return tlb->fast_mode;
-#else
- /*
- * For UP we don't need to worry about TLB flush
- * and page free order so much..
- */
- return 1;
-#endif
-}
-
void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm);
void tlb_flush_mmu(struct mmu_gather *tlb);
void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start,