• Jan Beulich's avatar
    x86: Avoid building unused IRQ entry stubs · 2414e021
    Jan Beulich authored
    When X86_LOCAL_APIC (i.e. unconditionally on x86-64),
    first_system_vector will never end up being higher than
    LOCAL_TIMER_VECTOR (0xef), and hence building stubs for vectors
    0xef...0xff is pointlessly reducing code density. Deal with this at
    build time already.
    
    Taking into consideration that X86_64 implies X86_LOCAL_APIC, also
    simplify (and hence make easier to read and more consistent with the
    change done here) some #if-s in arch/x86/kernel/irqinit.c.
    
    While we could further improve the packing of the IRQ entry stubs (the
    four ones now left in the last set could be fit into the four padding
    bytes each of the final four sets have) this doesn't seem to provide
    any real benefit: Both irq_entries_start and common_interrupt getting
    cache line aligned, eliminating the 30th set would just produce 32
    bytes of padding between the 29th and common_interrupt.
    
    [ tglx: Folded lguest fix from Dan Carpenter ]
    Signed-off-by: default avatarJan Beulich <jbeulich@suse.com>
    Cc: Dan Carpenter <dan.carpenter@oracle.com>
    Cc: Andi Kleen <ak@linux.intel.com>
    Cc: lguest@lists.ozlabs.org
    Cc: Rusty Russell <rusty@rustcorp.com.au>
    Link: http://lkml.kernel.org/r/54574D5F0200007800044389@mail.emea.novell.com
    Link: http://lkml.kernel.org/r/20141115185718.GB6530@mwandaSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    2414e021
hw_irq.h 6.82 KB