From 23d0b8b053391afe15c9667d80de77ca88e18b8b Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" <ebiederm@xmission.com> Date: Wed, 4 Oct 2006 02:16:49 -0700 Subject: [PATCH] [PATCH] genirq: irq: generalize the check for HARDIRQ_BITS This patch adds support for systems that cannot receive every interrupt on a single cpu simultaneously, in the check to see if we have enough HARDIRQ_BITS. MAX_HARDIRQS_PER_CPU becomes the count of the maximum number of hardare generated interrupts per cpu. On architectures that support per cpu interrupt delivery this can be a significant space savings and scalability bonus. This patch adds support for systems that cannot receive every interrupt on Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rajesh Shah <rajesh.shah@intel.com> Cc: Andi Kleen <ak@muc.de> Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> --- include/asm-x86_64/hardirq.h | 3 +++ include/linux/hardirq.h | 7 ++++++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/include/asm-x86_64/hardirq.h b/include/asm-x86_64/hardirq.h index 64a65ce2f41f..95d5e090ed89 100644 --- a/include/asm-x86_64/hardirq.h +++ b/include/asm-x86_64/hardirq.h @@ -6,6 +6,9 @@ #include <asm/pda.h> #include <asm/apic.h> +/* We can have at most NR_VECTORS irqs routed to a cpu at a time */ +#define MAX_HARDIRQS_PER_CPU NR_VECTORS + #define __ARCH_IRQ_STAT 1 #define local_softirq_pending() read_pda(__softirq_pending) diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 50d8b5744cf6..612472aaa79c 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -28,11 +28,16 @@ #ifndef HARDIRQ_BITS #define HARDIRQ_BITS 12 + +#ifndef MAX_HARDIRQS_PER_CPU +#define MAX_HARDIRQS_PER_CPU NR_IRQS +#endif + /* * The hardirq mask has to be large enough to have space for potentially * all IRQ sources in the system nesting on a single CPU. */ -#if (1 << HARDIRQ_BITS) < NR_IRQS +#if (1 << HARDIRQ_BITS) < MAX_HARDIRQS_PER_CPU # error HARDIRQ_BITS is too low! #endif #endif -- GitLab