Messages in this thread Patch in this message | | | Date | Mon, 19 Apr 2004 18:51:29 +0100 (BST) | From | Hugh Dickins <> | Subject | [PATCH] dontneed nonlinear |
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Jamie points out that madvise(MADV_DONTNEED) should unmap pages from a nonlinear area in such a way that the nonlinear offsets are preserved if the pages do turn out to be needed later after all, instead of reverting them to linearity: needs to pass down a zap_details block.
(But this still leaves mincore unaware of nonlinear vmas: bigger job.)
--- 2.6.6-rc1-bk4/include/linux/mm.h 2004-04-19 15:29:38.808606600 +0100 +++ linux/include/linux/mm.h 2004-04-19 16:15:16.925349584 +0100 @@ -439,7 +439,16 @@ struct file *shmem_file_setup(char * nam void shmem_lock(struct file * file, int lock); int shmem_zero_setup(struct vm_area_struct *); -struct zap_details; +/* + * Parameter block passed down to zap_pte_range in exceptional cases. + */ +struct zap_details { + struct vm_area_struct *nonlinear_vma; /* Check page->index if set */ + struct address_space *check_mapping; /* Check page->mapping if set */ + pgoff_t first_index; /* Lowest page->index to unmap */ + pgoff_t last_index; /* Highest page->index to unmap */ +}; + void zap_page_range(struct vm_area_struct *vma, unsigned long address, unsigned long size, struct zap_details *); int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm, --- 2.6.6-rc1-bk4/mm/madvise.c 2004-04-19 15:29:38.896593224 +0100 +++ linux/mm/madvise.c 2004-04-19 16:42:15.197334848 +0100 @@ -92,10 +92,19 @@ static long madvise_willneed(struct vm_a static long madvise_dontneed(struct vm_area_struct * vma, unsigned long start, unsigned long end) { + struct zap_details details; + if (vma->vm_flags & VM_LOCKED) return -EINVAL; - zap_page_range(vma, start, end - start, NULL); + if (unlikely(vma->vm_flags & VM_NONLINEAR)) { + details.check_mapping = NULL; + details.nonlinear_vma = vma; + details.first_index = 0; + details.last_index = ULONG_MAX; + zap_page_range(vma, start, end - start, &details); + } else + zap_page_range(vma, start, end - start, NULL); return 0; } --- 2.6.6-rc1-bk4/mm/memory.c 2004-04-19 15:29:38.902592312 +0100 +++ linux/mm/memory.c 2004-04-19 16:15:16.000000000 +0100 @@ -384,16 +384,6 @@ nomem: return -ENOMEM; } -/* - * Parameter block passed down to zap_pte_range in exceptional cases. - */ -struct zap_details { - struct vm_area_struct *nonlinear_vma; /* Check page->index if set */ - struct address_space *check_mapping; /* Check page->mapping if set */ - pgoff_t first_index; /* Lowest page->index to unmap */ - pgoff_t last_index; /* Highest page->index to unmap */ -}; - static void zap_pte_range(struct mmu_gather *tlb, pmd_t *pmd, unsigned long address, unsigned long size, struct zap_details *details) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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