Re: [Crash-utility] [PATCH v2 3/6] Add tree cmd support for maple tree

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?

> > 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"; }

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 ...

Thanks, Kazu