2012/7/17 Christoph Lameter <cl@xxxxxxxxx>: > On Tue, 17 Jul 2012, Joonsoo Kim wrote: > >> @@ -1382,6 +1382,8 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, >> >> err = do_migrate_pages(mm, old, new, >> capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE); >> + if (err > 0) >> + err = -EBUSY; >> >> mmput(mm); >> out: > > Why not have do_migrate_pages() return EBUSY if we do not need the number > of failed/retried pages? There is no serious reason. do_migrate_pages() have two callsites, although another one doesn't use return value. do_migrate_pages() is commented "Return the number of page ...". And my focus is fixing possible error in migrate_pages() syscall. So, I keep to return the number of failed/retired pages. If we really think the number of failed/retired pages is useless, in that time, instead that do_migrate_pages() return EBUSY, we can make migrate_pages() return EBUSY. I think it is better to fix all the related codes at one go. -- 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>