[PATCH v3] memblock: Add flags and nid info in memblock debugfs

From: Yuwei Guan
Date: Thu May 18 2023 - 05:15:05 EST


Currently, the memblock debugfs can display the count of memblock_type and
the base and end of the reg. However, when memblock_mark_*() or
memblock_set_node() is executed on some range, the information in the
existing debugfs cannot make it clear why the address is not consecutive.

For example,
cat /sys/kernel/debug/memblock/memory
0: 0x0000000080000000..0x00000000901fffff
1: 0x0000000090200000..0x00000000905fffff
2: 0x0000000090600000..0x0000000092ffffff
3: 0x0000000093000000..0x00000000973fffff
4: 0x0000000097400000..0x00000000b71fffff
5: 0x00000000c0000000..0x00000000dfffffff
6: 0x00000000e2500000..0x00000000f87fffff
7: 0x00000000f8800000..0x00000000fa7fffff
8: 0x00000000fa800000..0x00000000fd3effff
9: 0x00000000fd3f0000..0x00000000fd3fefff
10: 0x00000000fd3ff000..0x00000000fd7fffff
11: 0x00000000fd800000..0x00000000fd901fff
12: 0x00000000fd902000..0x00000000fd909fff
13: 0x00000000fd90a000..0x00000000fd90bfff
14: 0x00000000fd90c000..0x00000000ffffffff
15: 0x0000000880000000..0x0000000affffffff

So we can add flags and nid to this debugfs.

For example,
cat /sys/kernel/debug/memblock/memory
0: 0x0000000080000000..0x00000000901fffff NONE 0
1: 0x0000000090200000..0x00000000905fffff NOMAP 0
2: 0x0000000090600000..0x0000000092ffffff NONE 0
3: 0x0000000093000000..0x00000000973fffff NOMAP 0
4: 0x0000000097400000..0x00000000b71fffff NONE 0
5: 0x00000000c0000000..0x00000000dfffffff NONE 0
6: 0x00000000e2500000..0x00000000f87fffff NONE 0
7: 0x00000000f8800000..0x00000000fa7fffff NOMAP 0
8: 0x00000000fa800000..0x00000000fd3effff NONE 0
9: 0x00000000fd3f0000..0x00000000fd3fefff NOMAP 0
10: 0x00000000fd3ff000..0x00000000fd7fffff NONE 0
11: 0x00000000fd800000..0x00000000fd901fff NOMAP 0
12: 0x00000000fd902000..0x00000000fd909fff NONE 0
13: 0x00000000fd90a000..0x00000000fd90bfff NOMAP 0
14: 0x00000000fd90c000..0x00000000ffffffff NONE 0
15: 0x0000000880000000..0x0000000affffffff NONE 0

Signed-off-by: Yuwei Guan <ssawgyw@xxxxxxxxx>
---
v3:
- show string value for each memblock flag
---
mm/memblock.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index 511d4783dcf1..5fba53f98b2d 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -2143,13 +2143,23 @@ static int memblock_debug_show(struct seq_file *m, void *private)
struct memblock_region *reg;
int i;
phys_addr_t end;
+ static const char flagname[BITS_PER_LONG][8] = {
+ [0 ... (BITS_PER_LONG-1)] = "?",
+
+ [ilog2(MEMBLOCK_HOTPLUG)] = "HOTPLUG",
+ [ilog2(MEMBLOCK_MIRROR)] = "MIRROR",
+ [ilog2(MEMBLOCK_NOMAP)] = "NOMAP",
+ [ilog2(MEMBLOCK_DRIVER_MANAGED)] = "DRV_MNG",
+ };

for (i = 0; i < type->cnt; i++) {
reg = &type->regions[i];
end = reg->base + reg->size - 1;

seq_printf(m, "%4d: ", i);
- seq_printf(m, "%pa..%pa\n", &reg->base, &end);
+ seq_printf(m, "%pa..%pa ", &reg->base, &end);
+ seq_printf(m, "%8s ", reg->flags ? flagname[ilog2(reg->flags)] : "NONE");
+ seq_printf(m, "%4d\n", memblock_get_region_node(reg));
}
return 0;
}
--
2.34.1