From: Christian Brauner > Sent: 04 June 2019 10:43 ... > > > + u64 clone_flags = args->flags; > > > + int __user *child_tidptr = args->child_tid; > > > + unsigned long tls = args->tls; > > > + unsigned long stack_start = args->stack; > > > + unsigned long stack_size = args->stack_size; > > > > Some of these are only used once, so it's probably not worth sticking them in > > local variables. > > [1]: > Ok, will double check. > This was just to minimize copy-paste erros for variables which were used > multiple times. Even the ones that are used multiple times may be better being repeatedly read from args->xxx. If you are "lucky" 'args' will be in a register variables so all the accesses are cheap. With too many locals everything gets copied onto the actual stack - especially likely if there are any function calls (that might conceivably change *args) after the locals are initialised. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
