On Thu, Jun 27, 2019 at 09:12:50AM +0200, Peter Zijlstra wrote: > Josh came up with the following: > > + /* If the jump target is close, do a 2-byte nop: */ > + ".skip -(%l[l_yes] - 1b <= 126), 0x66\n" > + ".skip -(%l[l_yes] - 1b <= 126), 0x90\n" > + /* Otherwise do a 5-byte nop: */ > + ".skip -(%l[l_yes] - 1b > 126), 0x0f\n" > + ".skip -(%l[l_yes] - 1b > 126), 0x1f\n" > + ".skip -(%l[l_yes] - 1b > 126), 0x44\n" > + ".skip -(%l[l_yes] - 1b > 126), 0x00\n" > + ".skip -(%l[l_yes] - 1b > 126), 0x00\n" > > Which is a wonderfully gruesome hack :-) So I'll be playing with that > for a bit.
For those with interest; full patches at: https://lkml.kernel.org/r/[email protected]
