On 06/23/2014 12:49 PM, Andy Lutomirski wrote: > On 06/18/2014 02:44 AM, Qiaowei Ren wrote: >> This patch adds one MPX specific mmap interface, which only handles >> mpx related maps, including bounds table and bounds directory. >> >> In order to track MPX specific memory usage, this interface is added >> to stick new vm_flag VM_MPX in the vma_area_struct when create a >> bounds table or bounds directory. > > I imagine the linux-mm people would want to think about any new vm flag. > Why is this needed? These tables can take huge amounts of memory. In the worst-case scenario, the tables can be 4x the size of the data structure being tracked. IOW, a 1-page structure can require 4 bounds-table pages. My expectation is that folks using MPX are going to be keen on figuring out how much memory is being dedicated to it. With this feature, plus some grepping in /proc/$pid/smaps one could take a pretty good stab at it. I know VM flags are scarce, and I'm open to other ways to skin this cat. -- 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>