| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.17 81/97] x86/irq: Demote irq_cpustat_t::__softirq_pending to u16 | Date | Tue, 14 Aug 2018 19:17:33 +0200 |
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4.17-stable review patch. If anyone has any objections, please let me know.
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From: Nicolai Stange <nstange@suse.de>
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@redhat.com> Signed-off-by: Nicolai Stange <nstange@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- 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 @@ -6,7 +6,7 @@ #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 */
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