[ removed stable ] On Sun, 3 Feb 2008, Oleg Nesterov wrote: > Off-topic question to all. sys_remap_file_pages() doesn't work with > shared readonly mappings, why?
Slight correction: it works with shared readonly mappings, doesn't it, so long as the mmap'ed file was opened for reading and writing? > IOW, why it checks VM_SHARED but not VM_MAYSHARE? My guess has always been that it was just a misunderstanding of how those VM_ flags end up working: assume so unless Ingo corrects me. By the time I realized that oddity, we'd been driven into several tiresome corners by the very existence of sys_remap_file_pages. So whereas my usual instinct would have been to relax the restriction and generalize, in its case I wanted to hold on to every restriction we had. sys_remap_file_pages does serve a useful purpose; but it subverts vma principles, and has therefore caused us grief repeatedly. Hugh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
