Re: [PATCH v4] memblock: Add flags and nid info in memblock debugfs

[Yuwei Guan <ssawgyw@gmail.com>]

Mike Rapoport <rppt@kernel.org> 于2023年5月27日周六 18:37写道：
>
> Hi Yuwei,
>
> On Fri, May 19, 2023 at 06:53:21PM +0800, Yuwei Guan wrote:
> > 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    0 NONE
> >    1: 0x0000000090200000..0x00000000905fffff    0 NOMAP
> >    2: 0x0000000090600000..0x0000000092ffffff    0 NONE
> >    3: 0x0000000093000000..0x00000000973fffff    0 NOMAP
> >    4: 0x0000000097400000..0x00000000b71fffff    0 NONE
> >    5: 0x00000000c0000000..0x00000000dfffffff    0 NONE
> >    6: 0x00000000e2500000..0x00000000f87fffff    0 NONE
> >    7: 0x00000000f8800000..0x00000000fa7fffff    0 NOMAP
> >    8: 0x00000000fa800000..0x00000000fd3effff    0 NONE
> >    9: 0x00000000fd3f0000..0x00000000fd3fefff    0 NOMAP
> >   10: 0x00000000fd3ff000..0x00000000fd7fffff    0 NONE
> >   11: 0x00000000fd800000..0x00000000fd901fff    0 NOMAP
> >   12: 0x00000000fd902000..0x00000000fd909fff    0 NONE
> >   13: 0x00000000fd90a000..0x00000000fd90bfff    0 NOMAP
> >   14: 0x00000000fd90c000..0x00000000ffffffff    0 NONE
> >   15: 0x0000000880000000..0x0000000affffffff    0 NONE
> >
> > Signed-off-by: Yuwei Guan <ssawgyw@gmail.com>
> > ---
> > v4:
> > - show string value for each memblock flag
> > ---
> >  mm/memblock.c | 24 ++++++++++++++++++++++--
> >  1 file changed, 22 insertions(+), 2 deletions(-)
> >
> > diff --git a/mm/memblock.c b/mm/memblock.c
> > index 511d4783dcf1..10d0ddbeebc1 100644
> > --- a/mm/memblock.c
> > +++ b/mm/memblock.c
> > @@ -2136,12 +2136,19 @@ void __init memblock_free_all(void)
> >  }
> >
> >  #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_ARCH_KEEP_MEMBLOCK)
> > +static const char * const flagname[] = {
> > +     [ilog2(MEMBLOCK_HOTPLUG)] = "HOTPLUG",
> > +     [ilog2(MEMBLOCK_MIRROR)] = "MIRROR",
> > +     [ilog2(MEMBLOCK_NOMAP)] = "NOMAP",
> > +     [ilog2(MEMBLOCK_DRIVER_MANAGED)] = "DRV_MNG",
> > +};
> >
> >  static int memblock_debug_show(struct seq_file *m, void *private)
> >  {
> >       struct memblock_type *type = m->private;
> >       struct memblock_region *reg;
> > -     int i;
> > +     int i, j;
> > +     unsigned int count = ARRAY_SIZE(flagname);
> >       phys_addr_t end;
> >
> >       for (i = 0; i < type->cnt; i++) {
> > @@ -2149,7 +2156,20 @@ static int memblock_debug_show(struct seq_file *m, void *private)
> >               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, "%4d ", memblock_get_region_node(reg));
>
> As Kefeng mentioned, the node id for reserved regions will be wrong, so
> this needs to be updated so that when reg->nid == MAX_NUMNODES we'll print
> e.g. 'x'.
Hi Mike,

How about print 'x' when reg->nid == MAX_NUMNODES, base on this patch,
https://lore.kernel.org/linux-mm/44ce007d-8049-1cc9-7e2e-4ccb51a2867d@huawei.com/T/#m6d214d4ea8912b64f5efc9c3f51ae71aa057d1f1

diff --git a/mm/memblock.c b/mm/memblock.c
index c5c80d9bcea3..3d449aaba052 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -2169,17 +2169,21 @@ static int memblock_debug_show(struct seq_file
*m, void *private)
 {
  struct memblock_type *type = m->private;
  struct memblock_region *reg;
- int i, j;
+ int i, j, nid;
  unsigned int count = ARRAY_SIZE(flagname);
  phys_addr_t end;

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

  seq_printf(m, "%4d: ", i);
  seq_printf(m, "%pa..%pa ", &reg->base, &end);
- seq_printf(m, "%4d ", memblock_get_region_node(reg));
+ if (nid != MAX_NUMNODES)
+ seq_printf(m, "%4d ", nid);
+ else
+ seq_printf(m, "%4c ", 'x');
  if (reg->flags) {
  for (j = 0; j < count; j++) {
  if (reg->flags & (1U << j)) {

>
> > +             if (reg->flags) {
> > +                     for (j = 0; j < count; j++) {
> > +                             if (reg->flags & (1U << j)) {
> > +                                     seq_printf(m, "%s\n", flagname[j]);
> > +                                     break;
> > +                             }
> > +                     }
> > +                     if (j == count)
> > +                             seq_printf(m, "%s\n", "UNKNOWN");
> > +             } else {
> > +                     seq_printf(m, "%s\n", "NONE");
> > +             }
> >       }
> >       return 0;
> >  }
> > --
> > 2.34.1
> >
>
> --
> Sincerely yours,
> Mike.