From 25e5a76bae106e1673887db09e22b19cb1a86c45 Mon Sep 17 00:00:00 2001 From: Daniel J Blueman Date: Tue, 4 Nov 2014 16:29:42 +0800 Subject: [PATCH] x86: numachip: Elide self-IPI ICR polling The default self-IPI path polls the ICR to delay sending the IPI until there is no IPI in progress. This is redundant on x86-86 APICs, since IPIs are queued. See the AMD64 Architecture Programmer's Manual, vol 2, p525. Signed-off-by: Daniel J Blueman Cc: Steffen Persvold Cc: Bjorn Helgaas Link: http://lkml.kernel.org/r/1415089784-28779-2-git-send-email-daniel@numascale.com Signed-off-by: Thomas Gleixner --- arch/x86/kernel/apic/apic_numachip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/apic/apic_numachip.c b/arch/x86/kernel/apic/apic_numachip.c index 2aaee79fb129..7a3191232630 100644 --- a/arch/x86/kernel/apic/apic_numachip.c +++ b/arch/x86/kernel/apic/apic_numachip.c @@ -145,7 +145,7 @@ static void numachip_send_IPI_all(int vector) static void numachip_send_IPI_self(int vector) { - __default_send_IPI_shortcut(APIC_DEST_SELF, vector, APIC_DEST_PHYSICAL); + apic_write(APIC_SELF_IPI, vector); } static int __init numachip_probe(void) -- 2.39.5