old gcc versions are stupid with nested structs and need us
to initialize .tickets.head and .tickets.tail in one go
Change-Id: I0d4caf8236066e7edf4a12e3270114132ced9585
The attribute would impose 64-bytes alignment that we do not
respect later because the whole structures (e.g. process/thread)
are allocated at 32bytes boundaries with kmalloc
These are however justified for performance reason as we do not want
them on same page cache line, so just accept slower performance for
UBSAN only
Change-Id: Ia28968257675b7ae97b0391471986e6bf6485b7b
These macros are needed to make sure the compiler does not optimize away
atomic constructs such as "while (!READ_ONCE(foo))" loops that do not
modify foo within the loop
Also move the barrier() define where it belongs while we are here, it is
needed for READ_ONCE/WRITE_ONCE and including ihk/cpu.h here causes
include loops
Change-Id: Ia533a849ed674719ccbc0495be47d22a3c47b8f8