On 06/13/2019 09:01 PM, Matthew Wilcox wrote: > On Thu, Jun 13, 2019 at 08:51:17PM +0530, Anshuman Khandual wrote: >> acceptable ? What we have currently is wrong where vmap_pmd_range() could >> just wrap EBUSY as ENOMEM and send up the call chain. > > It's not wrong. We do it in lots of places. Unless there's a caller > which really needs to know the difference, it's often better than > returning the "real error". I can understand the fact that because there are no active users of this return code, the current situation has been alright. But then I fail to understand how can EBUSY be made ENOMEM and let the caller to think that vmap_page_rage() failed because of lack of memory when it is clearly not the case. It is really surprising how it can be acceptable inside kernel (init_mm) page table functions which need to be thorough enough.
