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authorEric W. Biederman <ebiederm@xmission.com>2006-10-04 02:16:49 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-04 07:55:28 -0700
commit23d0b8b053391afe15c9667d80de77ca88e18b8b (patch)
tree8ee6dd027581f794bcbffaa9022a3635ba59b04a /include
parent323a01c50832749d23664954f91df6fc43e73975 (diff)
[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>
Diffstat (limited to 'include')
-rw-r--r--include/asm-x86_64/hardirq.h3
-rw-r--r--include/linux/hardirq.h7
2 files changed, 9 insertions, 1 deletions
diff --git a/include/asm-x86_64/hardirq.h b/include/asm-x86_64/hardirq.h
index 64a65ce2f41..95d5e090ed8 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 50d8b5744cf..612472aaa79 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