I just would like to ask:
Is test_and_clear_bit guaranteed to be atomic on SMP machines? (I
would like to create my own locking from userland - ipc semaphores
are way too slow - and need some atomic operations...)
Depends upon the platform:
Intel: If 'lock' prefix is there, yes.
Alpha: yes
Sparc32: no
Sparc64: yes
PPC: yes (??? Cort, correct me if I'm wrong)
m68k: N/A yet 8-)
Later,
David "Sparc" Miller
davem@caip.rutgers.edu