[PATCH 6/9] mm: vmalloc: Support multiple zones in vmallocinfo

Uladzislau Rezki (Sony)
2023-05-22T11:15:15Z

A global vmap area busy tree has been removed and replaced by
multiple per-cpu trees/lists, therefore we need to traversal
all per-cpu busy-lists in order to dump all allocated objects.

Please note, after this patch, dumped addresses of allocated
areas are not sequential. See an example below:

0 1 2 0 1 2
|---|---|---|---|---|---|-> vmap space

There 3 CPUs dumping is done per-CPU zone, as you can see
address of zone_0 can be ahead of addresses residing in the
zone_1 or zone_2.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
---
mm/vmalloc.c | 90 ++++++++++++++++++++++++++--------------------------
1 file changed, 45 insertions(+), 45 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index a9170fe19909..dd83deb5ef4f 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -4159,26 +4159,18 @@ bool vmalloc_dump_obj(void *object)

#ifdef CONFIG_PROC_FS
static void *s_start(struct seq_file *m, loff_t *pos)
- __acquires(&vmap_purge_lock)
- __acquires(&fbl(&per_cpu(cpu_vmap_zone, 0), BUSY, lock))
{
- mutex_lock(&vmap_purge_lock);
- fbl_lock((&per_cpu(cpu_vmap_zone, 0)), BUSY);
-
- return seq_list_start(&fbl_head((&per_cpu(cpu_vmap_zone, 0)), BUSY), *pos);
+ return *pos < 1 ? (void *)1 : NULL;
}

static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
- return seq_list_next(p, &fbl_head((&per_cpu(cpu_vmap_zone, 0)), BUSY), pos);
+ ++*pos;
+ return NULL;
}

static void s_stop(struct seq_file *m, void *p)
- __releases(&fbl(&per_cpu(cpu_vmap_zone, 0), BUSY, lock))
- __releases(&vmap_purge_lock)
{
- fbl_unlock((&per_cpu(cpu_vmap_zone, 0)), BUSY);
- mutex_unlock(&vmap_purge_lock);
}

static void show_numa_info(struct seq_file *m, struct vm_struct *v)
@@ -4209,6 +4201,7 @@ static void show_purge_info(struct seq_file *m)
{
struct vmap_area *va;

+ mutex_lock(&vmap_purge_lock);
spin_lock(&purge_vmap_area_lock);
list_for_each_entry(va, &purge_vmap_area_list, list) {
seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n",
@@ -4216,65 +4209,72 @@ static void show_purge_info(struct seq_file *m)
va->va_end - va->va_start);
}
spin_unlock(&purge_vmap_area_lock);
+ mutex_unlock(&vmap_purge_lock);
}

static int s_show(struct seq_file *m, void *p)
{
+ struct cpu_vmap_zone *z;
struct vmap_area *va;
struct vm_struct *v;
+ int i;

- va = list_entry(p, struct vmap_area, list);
+ for_each_possible_cpu(i) {
+ z = per_cpu_ptr(&cpu_vmap_zone, i);

- if (!va->vm) {
- if (va->flags & VMAP_RAM)
- seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
- (void *)va->va_start, (void *)va->va_end,
- va->va_end - va->va_start);
+ fbl_lock(z, BUSY);
+ list_for_each_entry(va, &fbl_head(z, BUSY), list) {
+ if (!va->vm) {
+ if (va->flags & VMAP_RAM)
+ seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
+ (void *)va->va_start, (void *)va->va_end,
+ va->va_end - va->va_start);

- goto final;
- }
+ continue;
+ }

- v = va->vm;
+ v = va->vm;

- seq_printf(m, "0x%pK-0x%pK %7ld",
- v->addr, v->addr + v->size, v->size);
+ seq_printf(m, "0x%pK-0x%pK %7ld",
+ v->addr, v->addr + v->size, v->size);

- if (v->caller)
- seq_printf(m, " %pS", v->caller);
+ if (v->caller)
+ seq_printf(m, " %pS", v->caller);

- if (v->nr_pages)
- seq_printf(m, " pages=%d", v->nr_pages);
+ if (v->nr_pages)
+ seq_printf(m, " pages=%d", v->nr_pages);

- if (v->phys_addr)
- seq_printf(m, " phys=%pa", &v->phys_addr);
+ if (v->phys_addr)
+ seq_printf(m, " phys=%pa", &v->phys_addr);

- if (v->flags & VM_IOREMAP)
- seq_puts(m, " ioremap");
+ if (v->flags & VM_IOREMAP)
+ seq_puts(m, " ioremap");

- if (v->flags & VM_ALLOC)
- seq_puts(m, " vmalloc");
+ if (v->flags & VM_ALLOC)
+ seq_puts(m, " vmalloc");

- if (v->flags & VM_MAP)
- seq_puts(m, " vmap");
+ if (v->flags & VM_MAP)
+ seq_puts(m, " vmap");

- if (v->flags & VM_USERMAP)
- seq_puts(m, " user");
+ if (v->flags & VM_USERMAP)
+ seq_puts(m, " user");

- if (v->flags & VM_DMA_COHERENT)
- seq_puts(m, " dma-coherent");
+ if (v->flags & VM_DMA_COHERENT)
+ seq_puts(m, " dma-coherent");

- if (is_vmalloc_addr(v->pages))
- seq_puts(m, " vpages");
+ if (is_vmalloc_addr(v->pages))
+ seq_puts(m, " vpages");

- show_numa_info(m, v);
- seq_putc(m, '\n');
+ show_numa_info(m, v);
+ seq_putc(m, '\n');
+ }
+ fbl_unlock(z, BUSY);
+ }

/*
* As a final step, dump "unpurged" areas.
*/
-final:
- if (list_is_last(&va->list, &fbl_head((&per_cpu(cpu_vmap_zone, 0)), BUSY)))
- show_purge_info(m);
+ show_purge_info(m);

return 0;
}
--
2.30.2