When ioremap a 67112960 bytes vm_area with the vmallocinfo:
[..]
0xec79b000-0xec7fa000 389120 ftl_add_mtd+0x4d0/0x754 pages=94 vmalloc
0xec800000-0xecbe1000 4067328 kbox_proc_mem_write+0x104/0x1c4 phys=8b520000 ioremap
we get the result:
0xf1000000-0xf5001000 67112960 devm_ioremap+0x38/0x7c phys=40000000 ioremap
For the align for ioremap must be less than '1 << IOREMAP_MAX_ORDER':
if (flags & VM_IOREMAP)
align = 1ul << clamp_t(int, get_count_order_long(size),
PAGE_SHIFT, IOREMAP_MAX_ORDER);
So it makes idiot like me a litter puzzle why jump the vm_area from
0xec800000-0xecbe1000 to 0xf1000000-0xf5001000, and leave
0xed000000-0xf1000000 as a big hole.
This is to show all of vm_area, including which is freeing but still in
vmap_area_list, to make it more clear about why we will get
0xf1000000-0xf5001000 int the above case. And we will get the
vmallocinfo like:
[..]
0xec79b000-0xec7fa000 389120 ftl_add_mtd+0x4d0/0x754 pages=94 vmalloc
0xec800000-0xecbe1000 4067328 kbox_proc_mem_write+0x104/0x1c4 phys=8b520000 ioremap
[..]
0xece7c000-0xece7e000 8192 unpurged vm_area
0xece7e000-0xece83000 20480 vm_map_ram
0xf0099000-0xf00aa000 69632 vm_map_ram
after apply this patch.
Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx>
---
v2:
- changed "freeing vm_area" to "unpurged vm_area" to be clearer - Tim
mm/vmalloc.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 34a1c3e..6ef021f 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -314,6 +314,7 @@ unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
/*** Global kva allocator ***/
+#define VM_LAZY_FREE 0x02
#define VM_VM_AREA 0x04
static DEFINE_SPINLOCK(vmap_area_lock);
@@ -1486,6 +1487,7 @@ struct vm_struct *remove_vm_area(const void *addr)
spin_lock(&vmap_area_lock);
va->vm = NULL;
va->flags &= ~VM_VM_AREA;
+ va->flags |= VM_LAZY_FREE;
spin_unlock(&vmap_area_lock);
vmap_debug_free_range(va->va_start, va->va_end);
@@ -2698,8 +2700,14 @@ static int s_show(struct seq_file *m, void *p)
* s_show can encounter race with remove_vm_area, !VM_VM_AREA on
* behalf of vmap area is being tear down or vm_map_ram allocation.
*/
- if (!(va->flags & VM_VM_AREA))
+ if (!(va->flags & VM_VM_AREA)) {
+ seq_printf(m, "0x%pK-0x%pK %7ld %s\n",
+ (void *)va->va_start, (void *)va->va_end,
+ va->va_end - va->va_start,
+ va->flags & VM_LAZY_FREE ? "unpurged vm_area" : "vm_map_ram");
+
return 0;
+ }
v = va->vm;
--
1.7.12.4
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