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arch, mm: Remove tlb_fast_mode()

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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>
This commit is contained in:
Peter Zijlstra 2013-06-05 12:26:50 +02:00 • committed by Linus Torvalds
parent 2c95523c0f
commit 29eb77825c
4 changed files with 13 additions and 81 deletions
Download patch file Download diff file Expand all files Collapse all files

17
include/asm-generic/tlb.h
View file

@ -97,11 +97,9 @@ struct mmu_gather {
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 @@ struct mmu_gather {
#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,