From 321a8e9dcb714f3c350ba55e41ed447bf3f05fac Mon Sep 17 00:00:00 2001
From: Mike Travis <travis@sgi.com>
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 <hpa@zytor.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
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 67e0e38d32b1..629102feaa66 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 99ce94930b09..2df3f0617fdc 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.
--
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