• Thomas Gleixner's avatar
    x86/Kconfig: Select SCHED_SMT if SMP enabled · dbe73364
    Thomas Gleixner authored
    CONFIG_SCHED_SMT is enabled by all distros, so there is not a real point to
    have it configurable. The runtime overhead in the core scheduler code is
    minimal because the actual SMT scheduling parts are conditional on a static
    key.
    
    This allows to expose the scheduler's SMT state static key to the
    speculation control code. Alternatively the scheduler's static key could be
    made always available when CONFIG_SMP is enabled, but that's just adding an
    unused static key to every other architecture for nothing.
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    Reviewed-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Andy Lutomirski <luto@kernel.org>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Jiri Kosina <jkosina@suse.cz>
    Cc: Tom Lendacky <thomas.lendacky@amd.com>
    Cc: Josh Poimboeuf <jpoimboe@redhat.com>
    Cc: Andrea Arcangeli <aarcange@redhat.com>
    Cc: David Woodhouse <dwmw@amazon.co.uk>
    Cc: Tim Chen <tim.c.chen@linux.intel.com>
    Cc: Andi Kleen <ak@linux.intel.com>
    Cc: Dave Hansen <dave.hansen@intel.com>
    Cc: Casey Schaufler <casey.schaufler@intel.com>
    Cc: Asit Mallick <asit.k.mallick@intel.com>
    Cc: Arjan van de Ven <arjan@linux.intel.com>
    Cc: Jon Masters <jcm@redhat.com>
    Cc: Waiman Long <longman9394@gmail.com>
    Cc: Greg KH <gregkh@linuxfoundation.org>
    Cc: Dave Stewart <david.c.stewart@intel.com>
    Cc: Kees Cook <keescook@chromium.org>
    Cc: stable@vger.kernel.org
    Link: https://lkml.kernel.org/r/20181125185004.337452245@linutronix.de
    
    dbe73364
Kconfig 94.5 KB