On Mon, Nov 7, 2022 at 3:52 PM HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab@xxxxxxx> wrote:
>
> On 2022/10/25 21:38, Tao Liu wrote:
> > Maple tree is a new data structure for crash, so cmd_tree support is
> > needed for users to dump and view the content of maple tree. This patch
> > achieves this by porting mt_dump() and its related functions from kernel,
> > and adapting them with tree cmd.
>
> ah.. so the v2 patch set has almost two function sets to walk a
> maple tree, starting from vma_next() (i.e. mas_find()) and
> do_maple_tree_traverse(), right?
>
> My concern is that maybe we get different results between them.
> It will be better to use do_maple_tree(GATHER or DUMP_CB) for vma
> iteration, but it may be hard to emulate mas_find() well..
> What do you think?
>
Yes, I agree. I have removed mas_find(), and taken do_maple_tree(COUNT
& GATHER) as a way for maple tree iteration in v3.
> >
> > We introduced a new -v arg specifically for dumping the complete
> > content of maple tree:
> >
> > crash> tree -t maple 0xffff9034c006aec0 -v
> >
> > maple_tree(ffff9034c006aec0) flags 309, height 0 root 0xffff9034de70041e
> >
> > 0-18446744073709551615: node 0xffff9034de700400 depth 0 type 3 parent 0xffff9034c006aec1 contents:...
> > 0-140112331583487: node 0xffff9034c01e8800 depth 1 type 1 parent 0xffff9034de700406 contents:...
> > 0-94643156942847: (nil)
> > 94643156942848-94643158024191: 0xffff9035131754c0
> > 94643158024192-94643160117247: (nil)
> > ...
>
> Please add warnings about exclusive options, e.g.
>
> crash> tree -t xarray -v ...
> tree: -v option is not applicable to Xarrays
>
> crash> tree -t maple -l ...
> tree: -l option is not applicable to Maple trees
>
> It may be better to have a tree type string.
>
> else if (STRNEQ(optarg, "m")) {
> type_flag = MAPLE_REQUEST;
> type_name = "Maple trees";
> }
>
Thanks for the suggestion, fixed in v3.
> Also there is need to support CRASHDEBUG(1) in cmd_tree().
>
> crash> set debug 1
> debug: 1
> crash> tree -t maple 0xffff8bb804d54840 -v | head
> flags: 200 () <<--
> type: red-black (default) <<--
> node pointer: no
> start: ffff8bb804d54840
> node_member_offset: 0
> structname_args: 0
> count: 0
> maple_tree(ffff8bb804d54840) flags 30D, height 0 root 0xffff8bb803a19d1e
> ...
>
ditto.
Thanks,
Tao Liu
> Thanks,
> Kazu
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