On Thu, Jan 05, 2017 at 11:39:16AM -0800, Dave Hansen wrote: > On 01/05/2017 11:29 AM, Kirill A. Shutemov wrote: > > On Thu, Jan 05, 2017 at 11:13:57AM -0800, Dave Hansen wrote: > >> On 12/26/2016 05:54 PM, Kirill A. Shutemov wrote: > >>> MM would use min(RLIMIT_VADDR, TASK_SIZE) as upper limit of virtual > >>> address available to map by userspace. > >> > >> What happens to existing mappings above the limit when this upper limit > >> is dropped? > > > > Nothing: we only prevent creating new mappings. All existing are not > > affected. > > > > The semantics here the same as with other resource limits. > > > >> Similarly, why do we do with an application running with something > >> incompatible with the larger address space that tries to raise the > >> limit? Say, legacy MPX. > > > > It has to know what it does. Yes, it can change limit to the point where > > application is unusable. But you can to the same with other limits. > > I'm not sure I'm comfortable with this. Do other rlimit changes cause > silent data corruption? I'm pretty sure doing this to MPX would. Maybe it's too ugly, but MPX can set rlim_max to rlim_cur on enabling. -- Kirill A. Shutemov -- 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=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>