From 052c0bff9b83a578654dfa513d6e3d0b3795f1e8 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Thu, 21 Aug 2008 13:10:09 -0700 Subject: [PATCH] x86: fix probe_nr_irqs for xen otherwise Xen is _completely_ unusable with 5 or more VCPUs. (when !CONFIG_HAVE_SPARSE_IRQ). based on Alex Nixon's patch. also add +1 offset after redir_entries Signed-off-by: Yinghai Lu Acked-by: Jeremy Fitzhardinge Acked-by: Alex Nixon Signed-off-by: Ingo Molnar --- arch/x86/kernel/io_apic.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c index 4e44fd1f466..d28128e0392 100644 --- a/arch/x86/kernel/io_apic.c +++ b/arch/x86/kernel/io_apic.c @@ -3625,16 +3625,21 @@ int __init probe_nr_irqs(void) { int idx; int nr = 0; +#ifndef CONFIG_XEN + int nr_min = 32; +#else + int nr_min = NR_IRQS; +#endif for (idx = 0; idx < nr_ioapics; idx++) - nr += io_apic_get_redir_entries(idx); + nr += io_apic_get_redir_entries(idx) + 1; /* double it for hotplug and msi and nmi */ nr <<= 1; /* something wrong ? */ - if (nr < 32) - nr = 32; + if (nr < nr_min) + nr = nr_min; return nr; } -- 2.41.1