On Tue, Mar 28, 2023 at 06:28:21PM +0200, Vlastimil Babka wrote: > On 2/22/23 20:31, Suren Baghdasaryan wrote: > > We would like to continue the discussion about code tagging use for > > memory allocation profiling. The code tagging framework [1] and its > > applications were posted as an RFC [2] and discussed at LPC 2022. It > > has many applications proposed in the RFC but we would like to focus > > on its application for memory profiling. It can be used as a > > low-overhead solution to track memory leaks, rank memory consumers by > > the amount of memory they use, identify memory allocation hot paths > > and possible other use cases. > > Kent Overstreet and I worked on simplifying the solution, minimizing > > the overhead and implementing features requested during RFC review. > > IIRC one large objection was the use of page_ext, I don't recall if you > found another solution to that? No, page_ext is really the thing that makes the most sense here. It's per-page allocation information, so the only other place it could go is in struct page itself - but that doesn't make any sense with the boot time option we've got now, page_ext works perfectly with that.