mm/mmu_gather: enable tlb flush range in generic mmu_gather (597e1c35) · Commits · 戴 / test

This patch enabled the tlb flush range support in generic mmu layer. Most of arch has self tlb flush range support, like ARM/IA64 etc. X86 arch has no this support in hardware yet. But another instruction 'invlpg' can implement this function in some degree. So, enable this feather in generic layer for x86 now. and maybe useful for other archs in further. Generic mmu_gather struct is protected by micro HAVE_GENERIC_MMU_GATHER. Other archs that has flush range supported own self mmu_gather struct. So, now this change is safe for them. In future we may unify this struct and related functions on multiple archs. Thanks for Peter Zijlstra time and time reminder for multiple architecture code safe! Signed-off-by:

Alex Shi <alex.shi@intel.com> Link: http://lkml.kernel.org/r/1340845344-27557-7-git-send-email-alex.shi@intel.com Signed-off-by:

H. Peter Anvin <hpa@zytor.com>

include/asm-generic/tlb.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -86,6 +86,8 @@ struct mmu_gather {
		#ifdef CONFIG_HAVE_RCU_TABLE_FREE
		struct mmu_table_batch *batch;
		#endif
		unsigned long start;
		unsigned long end;
		unsigned int need_flush : 1, /* Did free PTEs */
		fast_mode : 1; /* No batching */

mm/memory.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -206,6 +206,8 @@ void tlb_gather_mmu(struct mmu_gather tlb, struct mm_struct mm, bool fullmm)
		tlb->mm = mm;

		tlb->fullmm = fullmm;
		tlb->start = -1UL;
		tlb->end = 0;
		tlb->need_flush = 0;
		tlb->fast_mode = (num_possible_cpus() == 1);
		tlb->local.next = NULL;
		@@ -248,6 +250,8 @@ void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long e
		{
		struct mmu_gather_batch batch, next;

		tlb->start = start;
		tlb->end = end;
		tlb_flush_mmu(tlb);

		/* keep the page table cache within bounds */
		@@ -1204,6 +1208,11 @@ again:
		*/
		if (force_flush) {
		force_flush = 0;

		#ifdef HAVE_GENERIC_MMU_GATHER
		tlb->start = addr;
		tlb->end = end;
		#endif
		tlb_flush_mmu(tlb);
		if (addr != end)
		goto again;

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