fc2acab31b
zap_pte_range has been counting the pages it frees in tlb->freed, then tlb_finish_mmu has used that to update the mm's rss. That got stranger when I added anon_rss, yet updated it by a different route; and stranger when rss and anon_rss became mm_counters with special access macros. And it would no longer be viable if we're relying on page_table_lock to stabilize the mm_counter, but calling tlb_finish_mmu outside that lock. Remove the mmu_gather's freed field, let tlb_finish_mmu stick to its own business, just decrement the rss mm_counter in zap_pte_range (yes, there was some point to batching the update, and a subsequent patch restores that). And forget the anal paranoia of first reading the counter to avoid going negative - if rss does go negative, just fix that bug. Remove the mmu_gather's flushes and avoided_flushes from arm and arm26: no use was being made of them. But arm26 alone was actually using the freed, in the way some others use need_flush: give it a need_flush. arm26 seems to prefer spaces to tabs here: respect that. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
86 lines
2.1 KiB
C
86 lines
2.1 KiB
C
/*
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* linux/include/asm-arm/tlb.h
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*
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* Copyright (C) 2002 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Experimentation shows that on a StrongARM, it appears to be faster
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* to use the "invalidate whole tlb" rather than "invalidate single
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* tlb" for this.
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*
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* This appears true for both the process fork+exit case, as well as
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* the munmap-large-area case.
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*/
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#ifndef __ASMARM_TLB_H
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#define __ASMARM_TLB_H
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#include <asm/pgalloc.h>
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/*
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* TLB handling. This allows us to remove pages from the page
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* tables, and efficiently handle the TLB issues.
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*/
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struct mmu_gather {
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struct mm_struct *mm;
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unsigned int fullmm;
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};
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DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
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static inline struct mmu_gather *
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tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
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{
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struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);
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tlb->mm = mm;
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tlb->fullmm = full_mm_flush;
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return tlb;
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}
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static inline void
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tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
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{
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if (tlb->fullmm)
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flush_tlb_mm(tlb->mm);
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/* keep the page table cache within bounds */
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check_pgt_cache();
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put_cpu_var(mmu_gathers);
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}
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#define tlb_remove_tlb_entry(tlb,ptep,address) do { } while (0)
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/*
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* In the case of tlb vma handling, we can optimise these away in the
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* case where we're doing a full MM flush. When we're doing a munmap,
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* the vmas are adjusted to only cover the region to be torn down.
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*/
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static inline void
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tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
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{
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if (!tlb->fullmm)
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flush_cache_range(vma, vma->vm_start, vma->vm_end);
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}
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static inline void
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tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
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{
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if (!tlb->fullmm)
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flush_tlb_range(vma, vma->vm_start, vma->vm_end);
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}
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#define tlb_remove_page(tlb,page) free_page_and_swap_cache(page)
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#define pte_free_tlb(tlb,ptep) pte_free(ptep)
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#define pmd_free_tlb(tlb,pmdp) pmd_free(pmdp)
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#define tlb_migrate_finish(mm) do { } while (0)
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#endif
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