Re: [PATCH] 4/4 i_mmap_lock spinlock2rwsem (#v9 was 1/4)

Christoph Lameter
2008-03-19T23:02:17Z

You need this patch to address the issues (that I already mentioned when I
sent the patch to you). New EMM notifier patch with sleeping coming soon.

From: Christoph Lameter <clameter@sgi.com>
Subject: Move tlb flushing into free_pgtables

Move the tlb flushing into free_pgtables. The conversion of the locks
taken for reverse map scanning would require taking sleeping locks
in free_pgtables. Moving the tlb flushing into free_pgtables allows
sleeping in part of free_pgtables().

Signed-off-by: Christoph Lameter <clameter@sgi.com>

---
include/linux/mm.h | 4 ++--
mm/memory.c | 14 ++++++++++----
mm/mmap.c | 6 +++---
3 files changed, 15 insertions(+), 9 deletions(-)

Index: linux-2.6/include/linux/mm.h
===================================================================
--- linux-2.6.orig/include/linux/mm.h 2008-03-19 13:30:51.460856986 -0700
+++ linux-2.6/include/linux/mm.h 2008-03-19 13:31:20.809377398 -0700
@@ -751,8 +751,8 @@ int walk_page_range(const struct mm_stru
void *private);
void free_pgd_range(struct mmu_gather **tlb, unsigned long addr,
unsigned long end, unsigned long floor, unsigned long ceiling);
-void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *start_vma,
- unsigned long floor, unsigned long ceiling);
+void free_pgtables(struct vm_area_struct *start_vma, unsigned long floor,
+ unsigned long ceiling);
int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
struct vm_area_struct *vma);
void unmap_mapping_range(struct address_space *mapping,
Index: linux-2.6/mm/memory.c
===================================================================
--- linux-2.6.orig/mm/memory.c 2008-03-19 13:29:06.007351495 -0700
+++ linux-2.6/mm/memory.c 2008-03-19 13:46:31.352774359 -0700
@@ -271,9 +271,11 @@ void free_pgd_range(struct mmu_gather **
} while (pgd++, addr = next, addr != end);
}

-void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *vma,
- unsigned long floor, unsigned long ceiling)
+void free_pgtables(struct vm_area_struct *vma, unsigned long floor,
+ unsigned long ceiling)
{
+ struct mmu_gather *tlb;
+
while (vma) {
struct vm_area_struct *next = vma->vm_next;
unsigned long addr = vma->vm_start;
@@ -285,8 +287,10 @@ void free_pgtables(struct mmu_gather **t
unlink_file_vma(vma);

if (is_vm_hugetlb_page(vma)) {
- hugetlb_free_pgd_range(tlb, addr, vma->vm_end,
+ tlb = tlb_gather_mmu(vma->vm_mm, 0);
+ hugetlb_free_pgd_range(&tlb, addr, vma->vm_end,
floor, next? next->vm_start: ceiling);
+ tlb_finish_mmu(tlb, addr, vma->vm_end);
} else {
/*
* Optimization: gather nearby vmas into one call down
@@ -298,8 +302,10 @@ void free_pgtables(struct mmu_gather **t
anon_vma_unlink(vma);
unlink_file_vma(vma);
}
- free_pgd_range(tlb, addr, vma->vm_end,
+ tlb = tlb_gather_mmu(vma->vm_mm, 0);
+ free_pgd_range(&tlb, addr, vma->vm_end,
floor, next? next->vm_start: ceiling);
+ tlb_finish_mmu(tlb, addr, vma->vm_end);
}
vma = next;
}
Index: linux-2.6/mm/mmap.c
===================================================================
--- linux-2.6.orig/mm/mmap.c 2008-03-19 13:29:48.659889667 -0700
+++ linux-2.6/mm/mmap.c 2008-03-19 13:30:36.296604891 -0700
@@ -1750,9 +1750,9 @@ static void unmap_region(struct mm_struc
update_hiwater_rss(mm);
unmap_vmas(&tlb, vma, start, end, &nr_accounted, NULL);
vm_unacct_memory(nr_accounted);
- free_pgtables(&tlb, vma, prev? prev->vm_end: FIRST_USER_ADDRESS,
- next? next->vm_start: 0);
tlb_finish_mmu(tlb, start, end);
+ free_pgtables(vma, prev? prev->vm_end: FIRST_USER_ADDRESS,
+ next? next->vm_start: 0);
emm_notify(mm, emm_invalidate_end, start, end);
}

@@ -2049,8 +2049,8 @@ void exit_mmap(struct mm_struct *mm)
/* Use -1 here to ensure all VMAs in the mm are unmapped */
end = unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL);
vm_unacct_memory(nr_accounted);
- free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, 0);
tlb_finish_mmu(tlb, 0, end);
+ free_pgtables(vma, FIRST_USER_ADDRESS, 0);

/*
* Walk the list again, actually closing and freeing it,