On Tue, Jun 28, 2022 at 10:53:50AM -0400, Brian Foster wrote: > On Tue, Jun 28, 2022 at 02:55:11PM +0200, Christian Brauner wrote: > > On Wed, Jun 15, 2022 at 05:34:02PM +0100, Matthew Wilcox wrote: > > > On Wed, Jun 15, 2022 at 10:43:33AM -0400, Brian Foster wrote: > > > > Interesting, thanks. I'll have to dig more into this to grok the current > > > > state of the radix-tree interface vs. the underlying data structure. If > > > > I follow correctly, you're saying the radix-tree api is essentially > > > > already a translation layer to the xarray these days, and we just need > > > > to move legacy users off the radix-tree api so we can eventually kill it > > > > off... > > > > > > If only it were that easy ... the XArray has a whole bunch of debugging > > > asserts to make sure the users are actually using it correctly, and a > > > lot of radix tree users don't (they're probably not buggy, but they > > > don't use the XArray's embedded lock). > > > > > > Anyway, here's a first cut at converting the PID allocator from the IDR > > > to the XArray API. It boots, but I haven't tried to do anything tricky > > > with PID namespaces or CRIU. > > > > It'd be great to see that conversion done. > > Fwiw, there's test cases for e.g. nested pid namespace creation with > > specifically requested PIDs in > > > > Ok, but I'm a little confused. Why open code the xarray usage as opposed > to work the idr bits closer to being able to use the xarray api (and/or > work the xarray to better support the idr use case)? I see 150+ callers > of idr_init(). Is the goal to eventually open code them all? That seems > a lot of potential api churn for something that is presumably a generic > interface (and perhaps inconsistent with ida, which looks like it uses > xarray directly?), but I'm probably missing details. It's not "open coding". It's "using the XArray API instead of the IDR API". The IDR API is inferior in a number of ways, and yes, I do want to be rid of it entirely.
