From 2414e021ac8d588f1b09f64891f69a3e26feadf1 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 3 Nov 2014 08:39:43 +0000 Subject: x86: Avoid building unused IRQ entry stubs 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: Jan Beulich Cc: Dan Carpenter Cc: Andi Kleen Cc: lguest@lists.ozlabs.org Cc: Rusty Russell Link: http://lkml.kernel.org/r/54574D5F0200007800044389@mail.emea.novell.com Link: http://lkml.kernel.org/r/20141115185718.GB6530@mwanda Signed-off-by: Thomas Gleixner --- arch/x86/lguest/boot.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/lguest') diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index aae9413..c1c1544 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -841,7 +841,7 @@ static void __init lguest_init_IRQ(void) { unsigned int i; - for (i = FIRST_EXTERNAL_VECTOR; i < NR_VECTORS; i++) { + for (i = FIRST_EXTERNAL_VECTOR; i < FIRST_SYSTEM_VECTOR; i++) { /* Some systems map "vectors" to interrupts weirdly. Not us! */ __this_cpu_write(vector_irq[i], i - FIRST_EXTERNAL_VECTOR); if (i != SYSCALL_VECTOR) -- cgit v1.1