On Fri, Mar 06, 2020 at 12:14:19PM +0100, Vlastimil Babka wrote: > 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); Yub. > > > > @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> Thanks!