From 321a8e9dcb714f3c350ba55e41ed447bf3f05fac Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Fri, 4 Apr 2008 18:11:02 -0700 Subject: [PATCH] cpumask: add CPU_MASK_ALL_PTR macro * Add a static cpumask_t variable "CPU_MASK_ALL_PTR" to use as a pointer reference to CPU_MASK_ALL. This reduces where possible the instances where CPU_MASK_ALL allocates and fills a large array on the stack. Used only if NR_CPUS > BITS_PER_LONG. * Change init/main.c to use new set_cpus_allowed_ptr(). Depends on: [sched-devel]: sched: add new set_cpus_allowed_ptr function Cc: H. Peter Anvin Signed-off-by: Mike Travis Signed-off-by: Ingo Molnar --- include/linux/cpumask.h | 6 ++++++ init/main.c | 7 ++++++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index 67e0e38d32b..629102feaa6 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -243,6 +243,8 @@ int __next_cpu(int n, const cpumask_t *srcp); [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \ } } +#define CPU_MASK_ALL_PTR (&CPU_MASK_ALL) + #else #define CPU_MASK_ALL \ @@ -251,6 +253,10 @@ int __next_cpu(int n, const cpumask_t *srcp); [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \ } } +/* cpu_mask_all is in init/main.c */ +extern cpumask_t cpu_mask_all; +#define CPU_MASK_ALL_PTR (&cpu_mask_all) + #endif #define CPU_MASK_NONE \ diff --git a/init/main.c b/init/main.c index 99ce94930b0..2df3f0617fd 100644 --- a/init/main.c +++ b/init/main.c @@ -363,6 +363,11 @@ static inline void smp_prepare_cpus(unsigned int maxcpus) { } #else +#if NR_CPUS > BITS_PER_LONG +cpumask_t cpu_mask_all __read_mostly = CPU_MASK_ALL; +EXPORT_SYMBOL(cpu_mask_all); +#endif + #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; @@ -811,7 +816,7 @@ static int __init kernel_init(void * unused) /* * init can run on any cpu. */ - set_cpus_allowed(current, CPU_MASK_ALL); + set_cpus_allowed_ptr(current, CPU_MASK_ALL_PTR); /* * Tell the world that we're going to be the grim * reaper of innocent orphaned children. -- 2.41.1