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authorJames Cleverdon <jamesclv@us.ibm.com>2005-11-05 17:25:53 +0100
committerLinus Torvalds <torvalds@g5.osdl.org>2005-11-14 19:55:13 -0800
commit6004e1b7effcbb385a6b7c790e4b8008682cf679 (patch)
treeb22c05874deeee6ee7ec75f98746717db5830d8d /arch/i386
parent89b831ef8bf5cfbb357dbc0a2e07700d7f20eec5 (diff)
[PATCH] i386/x86-64: Share interrupt vectors when there is a large number of interrupt sources
Here's a patch that builds on Natalie Protasevich's IRQ compression patch and tries to work for MPS boots as well as ACPI. It is meant for a 4-node IBM x460 NUMA box, which was dying because it had interrupt pins with GSI numbers > NR_IRQS and thus overflowed irq_desc. The problem is that this system has 270 GSIs (which are 1:1 mapped with I/O APIC RTEs) and an 8-node box would have 540. This is much bigger than NR_IRQS (224 for both i386 and x86_64). Also, there aren't enough vectors to go around. There are about 190 usable vectors, not counting the reserved ones and the unused vectors at 0x20 to 0x2F. So, my patch attempts to compress the GSI range and share vectors by sharing IRQs. Cc: "Protasevich, Natalie" <Natalie.Protasevich@unisys.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386')
-rw-r--r--arch/i386/kernel/acpi/boot.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c
index b66c13c0cc0..82754bb80e2 100644
--- a/arch/i386/kernel/acpi/boot.c
+++ b/arch/i386/kernel/acpi/boot.c
@@ -39,17 +39,14 @@
#ifdef CONFIG_X86_64
-static inline void acpi_madt_oem_check(char *oem_id, char *oem_table_id)
-{
-}
extern void __init clustered_apic_check(void);
-static inline int ioapic_setup_disabled(void)
-{
- return 0;
-}
+extern int gsi_irq_sharing(int gsi);
#include <asm/proto.h>
+static inline int acpi_madt_oem_check(char *oem_id, char *oem_table_id) { return 0; }
+
+
#else /* X86 */
#ifdef CONFIG_X86_LOCAL_APIC
@@ -57,6 +54,8 @@ static inline int ioapic_setup_disabled(void)
#include <mach_mpparse.h>
#endif /* CONFIG_X86_LOCAL_APIC */
+static inline int gsi_irq_sharing(int gsi) { return gsi; }
+
#endif /* X86 */
#define BAD_MADT_ENTRY(entry, end) ( \
@@ -459,7 +458,7 @@ int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
*irq = IO_APIC_VECTOR(gsi);
else
#endif
- *irq = gsi;
+ *irq = gsi_irq_sharing(gsi);
return 0;
}