Re: "ibstat -l" displays CA device list in an unsorted order

[Jason Gunthorpe <jgg@ziepe.ca>]

On Thu, Feb 27, 2020 at 09:48:45AM +0200, Haim Boozaglo wrote:
> 
> 
> On 2/26/2020 7:09 PM, Jason Gunthorpe wrote:
> > On Wed, Feb 26, 2020 at 03:57:49PM +0200, Leon Romanovsky wrote:
> > > On Wed, Feb 26, 2020 at 09:43:10AM -0400, Jason Gunthorpe wrote:
> > > > On Tue, Feb 25, 2020 at 10:25:49AM +0200, Haim Boozaglo wrote:
> > > > > 
> > > > > 
> > > > > On 2/24/2020 9:41 PM, Jason Gunthorpe wrote:
> > > > > > On Mon, Feb 24, 2020 at 08:06:56PM +0200, Haim Boozaglo wrote:
> > > > > > > Hi all,
> > > > > > > 
> > > > > > > When running "ibstat" or "ibstat -l", the output of CA device list
> > > > > > > is displayed in an unsorted order.
> > > > > > > 
> > > > > > > Before pull request #561, ibstat displayed the CA device list sorted in
> > > > > > > alphabetical order.
> > > > > > > 
> > > > > > > The problem is that users expect to have the output sorted in alphabetical
> > > > > > > order and now they get it not as expected (in an unsorted order).
> > > > > > 
> > > > > > Really? Why? That doesn't look like it should happen, the list is
> > > > > > constructed out of readdir() which should be sorted?
> > > > > > 
> > > > > > Do you know where this comes from?
> > > > > > 
> > > > > > Jason
> > > > > > 
> > > > > 
> > > > > readdir() gives us struct by struct and doesn't keep on alphabetical order.
> > > > > Before pull request #561 ibstat have used this API of libibumad:
> > > > > int umad_get_cas_names(char cas[][UMAD_CA_NAME_LEN], int max)
> > > > > 
> > > > > This API used this function:
> > > > > n = scandir(SYS_INFINIBAND, &namelist, NULL, alphasort);
> > > > > 
> > > > > scandir() can return a sorted CA device list in alphabetical order.
> > > > 
> > > > Oh what a weird unintended side effect.
> > > > 
> > > > Resolving it would require adding a sorting pass on a linked
> > > > list.. Will you try?
> > > 
> > > Please be aware that once ibstat will be converted to netlink, the order
> > > will change again.
> > 
> > This is why I suggest a function to sort the linked list that tools
> > needing sorted order can call. Then it doesn't matter how we got the list
> > 
> > Jason
> > 
> 
> I can just sort the list at the time of insertion of each node.

I'd rather not have to pay the sorting penalty for all users, it seems
only a few command line tools need the sort

Jason