[PATCH 4.9 086/107] x86/irq: Demote irq_cpustat_t::__softirq_pending to u16

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Nicolai Stange <nstange@xxxxxxx>

commit 9aee5f8a7e30330d0a8f4c626dc924ca5590aba5 upstream

An upcoming patch will extend KVM's L1TF mitigation in conditional mode
to also cover interrupts after VMEXITs. For tracking those, stores to a
new per-cpu flag from interrupt handlers will become necessary.

In order to improve cache locality, this new flag will be added to x86's
irq_cpustat_t.

Make some space available there by shrinking the ->softirq_pending bitfield
from 32 to 16 bits: the number of bits actually used is only NR_SOFTIRQS,
i.e. 10.

Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Nicolai Stange <nstange@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/x86/include/asm/hardirq.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -5,7 +5,7 @@
 #include <linux/irq.h>
 
 typedef struct {
-	unsigned int __softirq_pending;
+	u16	     __softirq_pending;
 	unsigned int __nmi_count;	/* arch dependent */
 #ifdef CONFIG_X86_LOCAL_APIC
 	unsigned int apic_timer_irqs;	/* arch dependent */