Re: [PATCH v2 3/3] vsprintf: dump full information of page flags in pGp

[David Hildenbrand]

On 01.02.21 14:23, David Hildenbrand wrote:
> On 01.02.21 12:56, Yafang Shao wrote:
> > Currently the pGp only shows the names of page flags, rather than
> > the full information including section, node, zone, last cpupid and
> > kasan tag. While it is not easy to parse these information manually
> > because there're so many flavors. Let's interpret them in pGp as well.
> >
> > - Before the patch,
> > [ 6343.396602] Slab 0x000000004382e02b objects=33 used=3 fp=0x000000009ae06ffc flags=0x17ffffc0010200(slab|head)
> >
> > - After the patch,
> > [ 6871.296131] Slab 0x00000000c0e19a37 objects=33 used=3 fp=0x00000000c4902159 flags=0x17ffffc0010200(Node 0,Zone 2,Lastcpupid 0x1fffff,slab|head)
>
> For debugging purposes, it might be helpful to have the actual zone name
> (and to know if the value is sane). You could obtain it (without other
> modifications) via
>
> const char zname = "Invalid";
>
> if (zone < MAX_NR_ZONES)
> 	zname = first_online_pgdat()->node_zones[zone].name;
>
>
> Similarly, it might also be helpful to indicate if a node is
> online/offline/invalid/.
>
> const char nstate = "Invalid";
>
> if (node_online(nid))
> 	nstate = "Online";
> else if (node_possible(nid))
> 	nstate = "Offline";

Just remembering that we have to take care of nid limits:

if (nid >= 0 && nid < MAX_NUMNODES) {
	if (node_online(nid))
		nstate = "Online";
	else if (node_possible(nid))
		nstate = "Offline";
}

--
Thanks,

David / dhildenb