On Fri, Apr 06, 2018 at 07:20:47AM +0000, Chandan Vn wrote: > Hi, > > I would like to start contributing to linux-mm community. > Could you please let me know the current work items which I can start > working on. > > Please note that I have been working on linux-mm from past 4 years but > mostly proprietary or not yet mainlined vendor codebase. We had a report of a problem a few weeks ago that I don't know if anybody is looking at yet. Perhaps you'd like to try fixing it. The report says that, under some unidentified workload, calling vmalloc can take many hundreds of milliseconds, and the problem is in alloc_vmap_area(). So a good plan of work would be to devise a kernel module which can produce a highly-fragmented vmap area, and demonstrate the problem. Once you've got a reliable reproducer, you can look at how to fix this problem. We probably need a better data structure; either enhance the existing rbtree of free areas, or change the data structure.
