[PATCH 66/94] fs/proc/task_mmu: Stop using linked list and highest_vm_end
From: Liam Howlett
Date: Wed Apr 28 2021 - 11:40:17 EST
Remove references to mm_struct linked list and highest_vm_end for when they are removed
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
fs/proc/task_mmu.c | 44 ++++++++++++++++++++++++++------------------
1 file changed, 26 insertions(+), 18 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 503e1355cf6e..f7ce3cc60cc7 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -164,14 +164,13 @@ static void *m_start(struct seq_file *m, loff_t *ppos)
static void *m_next(struct seq_file *m, void *v, loff_t *ppos)
{
struct proc_maps_private *priv = m->private;
- struct vm_area_struct *next, *vma = v;
+ struct vm_area_struct *next = NULL, *vma = v;
- if (vma == priv->tail_vma)
- next = NULL;
- else if (vma->vm_next)
- next = vma->vm_next;
- else
- next = priv->tail_vma;
+ if (vma != priv->tail_vma) {
+ next = vma_next(vma->vm_mm, vma);
+ if (!next)
+ next = priv->tail_vma;
+ }
*ppos = next ? next->vm_start : -1UL;
@@ -844,16 +843,16 @@ static int show_smaps_rollup(struct seq_file *m, void *v)
{
struct proc_maps_private *priv = m->private;
struct mem_size_stats mss;
- struct mm_struct *mm;
+ struct mm_struct *mm = priv->mm;
struct vm_area_struct *vma;
- unsigned long last_vma_end = 0;
+ unsigned long vma_start = 0, last_vma_end = 0;
int ret = 0;
+ MA_STATE(mas, &mm->mm_mt, 0, 0);
priv->task = get_proc_task(priv->inode);
if (!priv->task)
return -ESRCH;
- mm = priv->mm;
if (!mm || !mmget_not_zero(mm)) {
ret = -ESRCH;
goto out_put_task;
@@ -866,8 +865,13 @@ static int show_smaps_rollup(struct seq_file *m, void *v)
goto out_put_mm;
hold_task_mempolicy(priv);
+ vma = mas_find(&mas, 0);
+
+ if (unlikely(!vma))
+ goto empty_set;
- for (vma = priv->mm->mmap; vma;) {
+ vma_start = vma->vm_start;
+ do {
smap_gather_stats(vma, &mss, 0);
last_vma_end = vma->vm_end;
@@ -876,6 +880,7 @@ static int show_smaps_rollup(struct seq_file *m, void *v)
* access it for write request.
*/
if (mmap_lock_is_contended(mm)) {
+ mas_pause(&mas);
mmap_read_unlock(mm);
ret = mmap_read_lock_killable(mm);
if (ret) {
@@ -919,7 +924,8 @@ static int show_smaps_rollup(struct seq_file *m, void *v)
* contains last_vma_end.
* Iterate VMA' from last_vma_end.
*/
- vma = find_vma(mm, last_vma_end - 1);
+ mas.index = mas.last = last_vma_end - 1;
+ vma = mas_find(&mas, ULONG_MAX);
/* Case 3 above */
if (!vma)
break;
@@ -933,11 +939,10 @@ static int show_smaps_rollup(struct seq_file *m, void *v)
smap_gather_stats(vma, &mss, last_vma_end);
}
/* Case 2 above */
- vma = vma->vm_next;
- }
+ } while ((vma = mas_find(&mas, ULONG_MAX)) != NULL);
- show_vma_header_prefix(m, priv->mm->mmap->vm_start,
- last_vma_end, 0, 0, 0, 0);
+empty_set:
+ show_vma_header_prefix(m, vma_start, last_vma_end, 0, 0, 0, 0);
seq_pad(m, ' ');
seq_puts(m, "[rollup]\n");
@@ -1230,6 +1235,7 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
return -ESRCH;
mm = get_task_mm(task);
if (mm) {
+ MA_STATE(mas, &mm->mm_mt, 0, 0);
struct mmu_notifier_range range;
struct clear_refs_private cp = {
.type = type,
@@ -1249,19 +1255,21 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
}
if (type == CLEAR_REFS_SOFT_DIRTY) {
- for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ mas_lock(&mas);
+ mas_for_each(&mas, vma, ULONG_MAX) {
if (!(vma->vm_flags & VM_SOFTDIRTY))
continue;
vma->vm_flags &= ~VM_SOFTDIRTY;
vma_set_page_prot(vma);
}
+ mas_unlock(&mas);
inc_tlb_flush_pending(mm);
mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY,
0, NULL, mm, 0, -1UL);
mmu_notifier_invalidate_range_start(&range);
}
- walk_page_range(mm, 0, mm->highest_vm_end, &clear_refs_walk_ops,
+ walk_page_range(mm, 0, -1, &clear_refs_walk_ops,
&cp);
if (type == CLEAR_REFS_SOFT_DIRTY) {
mmu_notifier_invalidate_range_end(&range);
--
2.30.2