From: "Matthew Wilcox (Oracle)" Subject: fs/proc/task_mmu: stop using linked list and highest_vm_end Remove references to mm_struct linked list and highest_vm_end for when they are removed Link: https://lkml.kernel.org/r/20220426150616.3937571-45-Liam.Howlett@oracle.com Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Liam R. Howlett Cc: Catalin Marinas Cc: David Howells Cc: Vlastimil Babka Cc: Will Deacon Cc: Yu Zhao Signed-off-by: Andrew Morton --- fs/proc/internal.h | 2 - fs/proc/task_mmu.c | 73 ++++++++++++++++++++++++------------------- 2 files changed, 42 insertions(+), 33 deletions(-) --- a/fs/proc/internal.h~fs-proc-task_mmu-stop-using-linked-list-and-highest_vm_end +++ a/fs/proc/internal.h @@ -285,7 +285,7 @@ struct proc_maps_private { struct task_struct *task; struct mm_struct *mm; #ifdef CONFIG_MMU - struct vm_area_struct *tail_vma; + struct vma_iterator iter; #endif #ifdef CONFIG_NUMA struct mempolicy *task_mempolicy; --- a/fs/proc/task_mmu.c~fs-proc-task_mmu-stop-using-linked-list-and-highest_vm_end +++ a/fs/proc/task_mmu.c @@ -123,12 +123,26 @@ static void release_task_mempolicy(struc } #endif +static struct vm_area_struct *proc_get_vma(struct proc_maps_private *priv, + loff_t *ppos) +{ + struct vm_area_struct *vma = vma_next(&priv->iter); + + if (vma) { + *ppos = vma->vm_start; + } else { + *ppos = -2UL; + vma = get_gate_vma(priv->mm); + } + + return vma; +} + static void *m_start(struct seq_file *m, loff_t *ppos) { struct proc_maps_private *priv = m->private; unsigned long last_addr = *ppos; struct mm_struct *mm; - struct vm_area_struct *vma; /* See m_next(). Zero at the start or after lseek. */ if (last_addr == -1UL) @@ -152,31 +166,21 @@ static void *m_start(struct seq_file *m, return ERR_PTR(-EINTR); } + vma_iter_init(&priv->iter, mm, last_addr); hold_task_mempolicy(priv); - priv->tail_vma = get_gate_vma(mm); - - vma = find_vma(mm, last_addr); - if (vma) - return vma; + if (last_addr == -2UL) + return get_gate_vma(mm); - return priv->tail_vma; + return proc_get_vma(priv, 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; - - if (vma == priv->tail_vma) - next = NULL; - else if (vma->vm_next) - next = vma->vm_next; - else - next = priv->tail_vma; - - *ppos = next ? next->vm_start : -1UL; - - return next; + if (*ppos == -2UL) { + *ppos = -1UL; + return NULL; + } + return proc_get_vma(m->private, ppos); } static void m_stop(struct seq_file *m, void *v) @@ -872,16 +876,16 @@ static int show_smaps_rollup(struct seq_ { 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)) goto out_put_task; @@ -892,8 +896,13 @@ static int show_smaps_rollup(struct seq_ goto out_put_mm; hold_task_mempolicy(priv); + vma = mas_find(&mas, 0); - for (vma = priv->mm->mmap; vma;) { + if (unlikely(!vma)) + goto empty_set; + + vma_start = vma->vm_start; + do { smap_gather_stats(vma, &mss, 0); last_vma_end = vma->vm_end; @@ -902,6 +911,7 @@ static int show_smaps_rollup(struct seq_ * 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) { @@ -945,7 +955,7 @@ static int show_smaps_rollup(struct seq_ * contains last_vma_end. * Iterate VMA' from last_vma_end. */ - vma = find_vma(mm, last_vma_end - 1); + vma = mas_find(&mas, ULONG_MAX); /* Case 3 above */ if (!vma) break; @@ -959,11 +969,10 @@ static int show_smaps_rollup(struct seq_ 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"); @@ -1256,6 +1265,7 @@ static ssize_t clear_refs_write(struct f 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, @@ -1275,7 +1285,7 @@ static ssize_t clear_refs_write(struct f } if (type == CLEAR_REFS_SOFT_DIRTY) { - for (vma = mm->mmap; vma; vma = vma->vm_next) { + mas_for_each(&mas, vma, ULONG_MAX) { if (!(vma->vm_flags & VM_SOFTDIRTY)) continue; vma->vm_flags &= ~VM_SOFTDIRTY; @@ -1287,8 +1297,7 @@ static ssize_t clear_refs_write(struct f 0, NULL, mm, 0, -1UL); mmu_notifier_invalidate_range_start(&range); } - walk_page_range(mm, 0, mm->highest_vm_end, &clear_refs_walk_ops, - &cp); + walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp); if (type == CLEAR_REFS_SOFT_DIRTY) { mmu_notifier_invalidate_range_end(&range); flush_tlb_mm(mm); _