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| author | Jan Beulich <JBeulich@suse.com> | 2014-11-03 08:39:43 +0000 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2014-12-16 14:08:14 +0100 |
| commit | 2414e021ac8d588f1b09f64891f69a3e26feadf1 (patch) | |
| tree | b74763cf043cd03720f371141a0a77c3baf6369f /arch/x86/include | |
| parent | e10679825924580845c4825deaaddf5331ff627c (diff) | |
| download | linux-2414e021ac8d588f1b09f64891f69a3e26feadf1.tar.gz | |
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 <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@mwanda Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/hw_irq.h | 3 | ||||
| -rw-r--r-- | arch/x86/include/asm/irq_vectors.h | 6 |
2 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h index fa5d1e768ba3..8dbe237bd806 100644 --- a/arch/x86/include/asm/hw_irq.h +++ b/arch/x86/include/asm/hw_irq.h @@ -189,7 +189,8 @@ extern __visible void smp_call_function_single_interrupt(struct pt_regs *); extern __visible void smp_invalidate_interrupt(struct pt_regs *); #endif -extern void (*__initconst interrupt[NR_VECTORS-FIRST_EXTERNAL_VECTOR])(void); +extern void (*__initconst interrupt[FIRST_SYSTEM_VECTOR + - FIRST_EXTERNAL_VECTOR])(void); #ifdef CONFIG_TRACING #define trace_interrupt interrupt #endif diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h index 5702d7e3111d..666c89ec4bd7 100644 --- a/arch/x86/include/asm/irq_vectors.h +++ b/arch/x86/include/asm/irq_vectors.h @@ -126,6 +126,12 @@ #define NR_VECTORS 256 +#ifdef CONFIG_X86_LOCAL_APIC +#define FIRST_SYSTEM_VECTOR LOCAL_TIMER_VECTOR +#else +#define FIRST_SYSTEM_VECTOR NR_VECTORS +#endif + #define FPU_IRQ 13 #define FIRST_VM86_IRQ 3 |