On 3/2/20 8:36 PM, Minchan Kim wrote: > There is a demand[1] to support pid as well pidfd for process_madvise > to reduce unnecessary syscall to get pidfd if the user has control of > the target process(ie, they could guarantee the process is not gone > or pid is not reused). > > This patch aims for supporting both options like waitid(2). So, the > syscall is currently, > > int process_madvise(int which, pid_t pid, void *addr, > size_t length, int advise, unsigned long flag); This is again halfway between kernel and userspace description, so if we stick to userspace then it's: int process_madvise(idtype_t idtype, id_t id, void *addr, size_t length, int advice, unsigned long flags); > @which is actually idtype_t for userspace libray and currently, > it supports P_PID and P_PIDFD. > > [1] https://lore.kernel.org/linux-mm/9d849087-3359-c4ab-fbec-859e8186c509@xxxxxxxxxxxxx/ > > Cc: Christian Brauner <christian@xxxxxxxxxx> > Reviewed-by: Suren Baghdasaryan <surenb@xxxxxxxxxx> > Suggested-by: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx> > Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
