On Wed, Feb 7, 2018 at 9:05 AM, Linus Torvalds <torva...@linux-foundation.org> wrote: > > The other thing we need to do is to just pass down the system call > number as an argument instead of reloading it.
.. we may also want to disable some debug things. For example, if you enable KASAN, it does insane things for do_syscall(). I realize that nobody is supposed to care about performance for KASAN, but still... So one of the issues with do_syscall() is simply that _because_ it was the rare case only, the code simply was never even looked at. But if y ou look at the straight-line case, do_syscall_64() really doesn't look too bad apart from the argument reloading that I do think is largely fixable. Linus