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| author | Zwane Mwaikambo <zwane@arm.linux.org.uk> | 2005-09-03 15:56:51 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@evo.osdl.org> | 2005-09-05 00:06:13 -0700 |
| commit | 4ad8d38342430f8b52f7a8458dce90caf8c8ca64 (patch) | |
| tree | 090c471fdb44d8fe88c52e95be0e8e43e31fcd5a /include | |
| parent | d7271b14b2e9e5905aba0fbf5c4dc4f8980c0cb2 (diff) | |
| download | lwn-4ad8d38342430f8b52f7a8458dce90caf8c8ca64.tar.gz lwn-4ad8d38342430f8b52f7a8458dce90caf8c8ca64.zip | |
[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 <alexn@telia.com>
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 <zwane@arm.linux.org.uk>
Signed-off-by: Alexander Nyberg <alexn@telia.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-i386/smp.h | 2 |
1 files changed, 1 insertions, 1 deletions
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) |