Hi everybody, Here is a note from the PyPy project (mentioned earlier in this thread, and at https://lwn.net/Articles/587923/ ). Yes, we use remap_file_pages() heavily on the x86-64 architecture. However, the individual calls to remap_file_pages() are not performance-critical, so it is easy to switch to using multiple mmap()s. We need to perform more measurements to know exactly what the overhead would be, in terms notably of kernel memory. However, an issue with that approach is the upper bound on the number of VMAs. By default, it is not large enough. Right now, it is possible to remap say 10% of the individual pages from an anonymous mmap of multiple GBs in size; but doing so with individual calls to mmap hits this arbitrary limit. I have no particular weight to give for or against keeping remap_file_pages() in the kernel, but if it is removed or emulated, it would be a plus if the programs would run on a machine with the default configuration --- i.e. if you remove or emulate remap_file_pages(), please increase the default limit as well. A bientôt, Armin. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href