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| author | Eric W. Biederman <ebiederm@xmission.com> | 2006-10-04 02:16:49 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-04 07:55:28 -0700 |
| commit | 23d0b8b053391afe15c9667d80de77ca88e18b8b (patch) | |
| tree | 8ee6dd027581f794bcbffaa9022a3635ba59b04a | |
| parent | 323a01c50832749d23664954f91df6fc43e73975 (diff) | |
| download | blackbird-op-linux-23d0b8b053391afe15c9667d80de77ca88e18b8b.tar.gz blackbird-op-linux-23d0b8b053391afe15c9667d80de77ca88e18b8b.zip | |
[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>
| -rw-r--r-- | include/asm-x86_64/hardirq.h | 3 | ||||
| -rw-r--r-- | include/linux/hardirq.h | 7 |
2 files changed, 9 insertions, 1 deletions
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 |
