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[Qemu-devel] [RFC 1/3] using CPUMASK bitmaps to calculate cpu index
From: |
Chen Fan |
Subject: |
[Qemu-devel] [RFC 1/3] using CPUMASK bitmaps to calculate cpu index |
Date: |
Tue, 13 May 2014 18:08:47 +0800 |
instead of seeking the number of CPUs, using CPUMASK bitmaps to
calculate the cpu index, also would be a gread benefit to remove
cpu index.
Signed-off-by: Chen Fan <address@hidden>
---
exec.c | 9 ++++-----
include/qom/cpu.h | 9 +++++++++
include/sysemu/sysemu.h | 7 -------
3 files changed, 13 insertions(+), 12 deletions(-)
diff --git a/exec.c b/exec.c
index cf12049..2948841 100644
--- a/exec.c
+++ b/exec.c
@@ -473,16 +473,15 @@ void cpu_exec_init(CPUArchState *env)
{
CPUState *cpu = ENV_GET_CPU(env);
CPUClass *cc = CPU_GET_CLASS(cpu);
- CPUState *some_cpu;
int cpu_index;
#if defined(CONFIG_USER_ONLY)
cpu_list_lock();
#endif
- cpu_index = 0;
- CPU_FOREACH(some_cpu) {
- cpu_index++;
- }
+ cpu_index = find_first_zero_bit(cc->cpu_present_mask,
+ MAX_CPUMASK_BITS);
+ set_bit(cpu_index, cc->cpu_present_mask);
+
cpu->cpu_index = cpu_index;
cpu->numa_node = 0;
QTAILQ_INIT(&cpu->breakpoints);
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index df977c8..b8f46b1 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -70,6 +70,13 @@ typedef void (*CPUUnassignedAccess)(CPUState *cpu, hwaddr
addr,
struct TranslationBlock;
+/* The following shall be true for all CPUs:
+ * cpu->cpu_index < max_cpus <= MAX_CPUMASK_BITS
+ *
+ * Note that cpu->get_arch_id() may be larger than MAX_CPUMASK_BITS.
+ */
+#define MAX_CPUMASK_BITS 255
+
/**
* CPUClass:
* @class_by_name: Callback to map -cpu command line model name to an
@@ -142,6 +149,8 @@ typedef struct CPUClass {
const struct VMStateDescription *vmsd;
int gdb_num_core_regs;
const char *gdb_core_xml_file;
+
+ DECLARE_BITMAP(cpu_present_mask, MAX_CPUMASK_BITS);
} CPUClass;
#ifdef HOST_WORDS_BIGENDIAN
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index ba5c7f8..04edb8b 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -134,13 +134,6 @@ extern QEMUClockType rtc_clock;
#define MAX_NODES 64
-/* The following shall be true for all CPUs:
- * cpu->cpu_index < max_cpus <= MAX_CPUMASK_BITS
- *
- * Note that cpu->get_arch_id() may be larger than MAX_CPUMASK_BITS.
- */
-#define MAX_CPUMASK_BITS 255
-
extern int nb_numa_nodes;
extern uint64_t node_mem[MAX_NODES];
extern unsigned long *node_cpumask[MAX_NODES];
--
1.8.1.4