On Wed, 13 Aug 2025 05:18:31 +0100 Lorenzo Stoakes <lorenzo.stoa...@oracle.com> wrote:
> On Tue, Aug 12, 2025 at 01:13:26PM -0700, SeongJae Park wrote: > > On Tue, 12 Aug 2025 16:44:09 +0100 Lorenzo Stoakes > > <lorenzo.stoa...@oracle.com> wrote: [...] > > > In order to execute this change, we introduce a new opaque type - > > > mm_flags_t - which wraps a bitmap. > > > > I have no strong opinion here, but I think coding-style.rst[1] has one? To > > quote, > > > > Please don't use things like ``vps_t``. > > It's a **mistake** to use typedef for structures and pointers. > > You stopped reading the relevant section in [1] :) Keep going and you see: > > Lots of people think that typedefs help readability. Not so. They > are useful only for: totally opaque objects (where the typedef is > actively used to hide what the object is). Example: pte_t > etc. opaque objects that you can only access using the proper > accessor functions. > > So this is what this is. > > The point is that it's opaque, that is you aren't supposed to know about or > care about what's inside, you use the accessors. > > This means we can extend the size of this thing as we like, and can enforce > atomicity through the accessors. > > We further highlight the opaqueness through the use of the __private. > > > > > checkpatch.pl also complains similarly. > > > > Again, I have no strong opinion, but I think adding a clarification about > > why > > we use typedef despite of the documented recommendation here might be nice? > > I already gave one, I clearly indicate it's opaque. You're completely right and I agree all the points. Thank you for kindly enlightening me :) Thanks, SJ [...]
