On 05/04, Eric W. Biederman wrote: > > Oleg Nesterov <o...@redhat.com> writes: > > > I'd vote for the change in exec_mmap(). This way mm_init_memcg() can just > > nullify mm->memcg. > > There is at least one common path where we need the memory control group > properly initialized so memory allocations don't escape the memory > control group. > > do_execveat_common > copy_strings > get_arg_page > get_user_pages_remote > __get_user_pages_locked > __get_user_pages > faultin_page > handle_mm_fault > count_memcg_event_mm > __handle_mm_fault > handle_pte_fault > do_anonymous_page > mem_cgroup_try_charge > > I am surprised I can't easily find more. Apparently in load_elf_binary > we call elf_mmap after set_new_exec and install_exec_creds, making > a gracefull recovery from elf_mmap failures impossible. > > In any case we most definitely need the memory control group properly > setup before exec_mmap.
Confused ... new_mm->memcg has no effect until exec_mmap(), why it can't be NULL ? and why do you think mem_cgroup_try_charge() can use the wrong memcg in this case? Oleg.
