[PATCH] freepgt: remove MM_VM_SIZE(mm)
There's only one usage of MM_VM_SIZE(mm) left, and it's a troublesome macro
because mm doesn't contain the (32-bit emulation?) info needed. But it too is
only needed because we ignore the end from the vma list.
We could make flush_pgtables return that end, or unmap_vmas. Choose the
latter, since it's a natural fit with unmap_mapping_range_vma needing to know
its restart addr. This does make more than minimal change, but if unmap_vmas
had returned the end before, this is how we'd have done it, rather than
storing the break_addr in zap_details.
unmap_vmas used to return count of vmas scanned, but that's just debug which
hasn't been useful in a while; and if we want the map_count 0 on exit check
back, it can easily come from the final remove_vm_struct loop.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/memory.c b/mm/memory.c
index fee5dc8..854bd90 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -645,7 +645,7 @@
* @nr_accounted: Place number of unmapped pages in vm-accountable vma's here
* @details: details of nonlinear truncation or shared cache invalidation
*
- * Returns the number of vma's which were covered by the unmapping.
+ * Returns the end address of the unmapping (restart addr if interrupted).
*
* Unmap all pages in the vma list. Called under page_table_lock.
*
@@ -662,7 +662,7 @@
* ensure that any thus-far unmapped pages are flushed before unmap_vmas()
* drops the lock and schedules.
*/
-int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,
+unsigned long unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,
struct vm_area_struct *vma, unsigned long start_addr,
unsigned long end_addr, unsigned long *nr_accounted,
struct zap_details *details)
@@ -670,12 +670,11 @@
unsigned long zap_bytes = ZAP_BLOCK_SIZE;
unsigned long tlb_start = 0; /* For tlb_finish_mmu */
int tlb_start_valid = 0;
- int ret = 0;
+ unsigned long start = start_addr;
spinlock_t *i_mmap_lock = details? details->i_mmap_lock: NULL;
int fullmm = tlb_is_full_mm(*tlbp);
for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) {
- unsigned long start;
unsigned long end;
start = max(vma->vm_start, start_addr);
@@ -688,7 +687,6 @@
if (vma->vm_flags & VM_ACCOUNT)
*nr_accounted += (end - start) >> PAGE_SHIFT;
- ret++;
while (start != end) {
unsigned long block;
@@ -719,7 +717,6 @@
if (i_mmap_lock) {
/* must reset count of rss freed */
*tlbp = tlb_gather_mmu(mm, fullmm);
- details->break_addr = start;
goto out;
}
spin_unlock(&mm->page_table_lock);
@@ -733,7 +730,7 @@
}
}
out:
- return ret;
+ return start; /* which is now the end (or restart) address */
}
/**
@@ -743,7 +740,7 @@
* @size: number of bytes to zap
* @details: details of nonlinear truncation or shared cache invalidation
*/
-void zap_page_range(struct vm_area_struct *vma, unsigned long address,
+unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
unsigned long size, struct zap_details *details)
{
struct mm_struct *mm = vma->vm_mm;
@@ -753,15 +750,16 @@
if (is_vm_hugetlb_page(vma)) {
zap_hugepage_range(vma, address, size);
- return;
+ return end;
}
lru_add_drain();
spin_lock(&mm->page_table_lock);
tlb = tlb_gather_mmu(mm, 0);
- unmap_vmas(&tlb, mm, vma, address, end, &nr_accounted, details);
+ end = unmap_vmas(&tlb, mm, vma, address, end, &nr_accounted, details);
tlb_finish_mmu(tlb, address, end);
spin_unlock(&mm->page_table_lock);
+ return end;
}
/*
@@ -1348,7 +1346,7 @@
* i_mmap_lock.
*
* In order to make forward progress despite repeatedly restarting some
- * large vma, note the break_addr set by unmap_vmas when it breaks out:
+ * large vma, note the restart_addr from unmap_vmas when it breaks out:
* and restart from that address when we reach that vma again. It might
* have been split or merged, shrunk or extended, but never shifted: so
* restart_addr remains valid so long as it remains in the vma's range.
@@ -1386,8 +1384,8 @@
}
}
- details->break_addr = end_addr;
- zap_page_range(vma, start_addr, end_addr - start_addr, details);
+ restart_addr = zap_page_range(vma, start_addr,
+ end_addr - start_addr, details);
/*
* We cannot rely on the break test in unmap_vmas:
@@ -1398,14 +1396,14 @@
need_break = need_resched() ||
need_lockbreak(details->i_mmap_lock);
- if (details->break_addr >= end_addr) {
+ if (restart_addr >= end_addr) {
/* We have now completed this vma: mark it so */
vma->vm_truncate_count = details->truncate_count;
if (!need_break)
return 0;
} else {
/* Note restart_addr in vma's truncate_count field */
- vma->vm_truncate_count = details->break_addr;
+ vma->vm_truncate_count = restart_addr;
if (!need_break)
goto again;
}