On 20 January 2016 at 03:44, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > Any thoughts on the obvious back-compatibility concerns? ie, why did > Siddhesh implement this in the first place? My bad for not ensuring > that the changelog told us this. > > https://lkml.org/lkml/2012/1/14/25 has more info: > > : Memory mmaped by glibc for a thread stack currently shows up as a > : simple anonymous map, which makes it difficult to differentiate between > : memory usage of the thread on stack and other dynamic allocation. > : Since glibc already uses MAP_STACK to request this mapping, the > : attached patch uses this flag to add additional VM_STACK_FLAGS to the > : resulting vma so that the mapping is treated as a stack and not any > : regular anonymous mapping. Also, one may use vm_flags to decide if a > : vma is a stack. > > But even that doesn't really tell us what the actual *value* of the > patch is to end-users. The end users needed a way to identify thread stacks programmatically and there wasn't a way to do that. I'm afraid I no longer remember (or have access to the resources that would aid my memory since I changed employers) the details of their requirement. However, I did do this on my own time because I thought it was an interesting project for me and nobody really gave any feedback then as to its utility, so as far as I am concerned you could roll back the main thread maps information since the information is available in the thread-specific files. Siddhesh -- http://siddhesh.in -- 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>