From 4ad8d38342430f8b52f7a8458dce90caf8c8ca64 Mon Sep 17 00:00:00 2001 From: Zwane Mwaikambo Date: Sat, 3 Sep 2005 15:56:51 -0700 Subject: [PATCH] i386 boottime for_each_cpu broken for_each_cpu walks through all processors in cpu_possible_map, which is defined as cpu_callout_map on i386 and isn't initialised until all processors have been booted. This breaks things which do for_each_cpu iterations early during boot. So, define cpu_possible_map as a bitmap with NR_CPUS bits populated. This was triggered by a patch i'm working on which does alloc_percpu before bringing up secondary processors. From: Alexander Nyberg i386-boottime-for_each_cpu-broken.patch i386-boottime-for_each_cpu-broken-fix.patch The SMP version of __alloc_percpu checks the cpu_possible_map before allocating memory for a certain cpu. With the above patches the BSP cpuid is never set in cpu_possible_map which breaks CONFIG_SMP on uniprocessor machines (as soon as someone tries to dereference something allocated via __alloc_percpu, which in fact is never allocated since the cpu is not set in cpu_possible_map). Signed-off-by: Zwane Mwaikambo Signed-off-by: Alexander Nyberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-i386/smp.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/asm-i386/smp.h b/include/asm-i386/smp.h index a283738b80b3..13250199976d 100644 --- a/include/asm-i386/smp.h +++ b/include/asm-i386/smp.h @@ -59,7 +59,7 @@ extern void cpu_uninit(void); extern cpumask_t cpu_callout_map; extern cpumask_t cpu_callin_map; -#define cpu_possible_map cpu_callout_map +extern cpumask_t cpu_possible_map; /* We don't mark CPUs online until __cpu_up(), so we need another measure */ static inline int num_booting_cpus(void) -- cgit v1.2.3