[Xen-devel] [PATCH v4 3/7] x86: initialize per socket cpu map

[Dongxiao Xu <dongxiao.xu@xxxxxxxxx>]

For each socket in the system, we create a separate bitmap to tag its
related CPUs. This per socket bitmap will be initialized on system
start up, and adjusted when CPU is dynamically online/offline.

Signed-off-by: Dongxiao Xu <dongxiao.xu@xxxxxxxxx>
---
 xen/arch/x86/smp.c        |    7 ++++++-
 xen/arch/x86/smpboot.c    |   19 +++++++++++++++++--
 xen/include/asm-x86/smp.h |    2 ++
 xen/include/xen/cpumask.h |    1 +
 4 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/xen/arch/x86/smp.c b/xen/arch/x86/smp.c
index 0433f30..7959447 100644
--- a/xen/arch/x86/smp.c
+++ b/xen/arch/x86/smp.c
@@ -283,6 +283,9 @@ void smp_send_call_function_mask(const cpumask_t *mask)
 
 void __stop_this_cpu(void)
 {
+    int cpu = smp_processor_id();
+    int socket = cpu_to_socket(cpu);
+
     ASSERT(!local_irq_is_enabled());
 
     disable_local_APIC();
@@ -296,7 +299,9 @@ void __stop_this_cpu(void)
     clts();
     asm volatile ( "fninit" );
 
-    cpumask_clear_cpu(smp_processor_id(), &cpu_online_map);
+    cpumask_clear_cpu(cpu, &cpu_online_map);
+    if ( socket >= 0 )
+        cpumask_clear_cpu(cpu, &socket_cpu_map[socket]);
 }
 
 static void stop_this_cpu(void *dummy)
diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index 9f81c7b..c421464 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -59,6 +59,9 @@ DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_mask);
 cpumask_t cpu_online_map __read_mostly;
 EXPORT_SYMBOL(cpu_online_map);
 
+cpumask_t socket_cpu_map[MAX_NUM_SOCKETS] __read_mostly;
+EXPORT_SYMBOL(socket_random_cpu_map);
+
 struct cpuinfo_x86 cpu_data[NR_CPUS];
 
 u32 x86_cpu_to_apicid[NR_CPUS] __read_mostly =
@@ -319,6 +322,7 @@ void start_secondary(void *unused)
      * want to limit the things done here to the most necessary things.
      */
     unsigned int cpu = booting_cpu;
+    int socket;
 
     set_processor_id(cpu);
     set_current(idle_vcpu[cpu]);
@@ -381,6 +385,9 @@ void start_secondary(void *unused)
     cpumask_set_cpu(cpu, &cpu_online_map);
     unlock_vector_lock();
 
+    if ( (socket = cpu_to_socket(cpu)) >= 0 )
+        cpumask_set_cpu(cpu, &socket_cpu_map[socket]);
+
     init_percpu_time();
 
     /* We can take interrupts now: we're officially "up". */
@@ -788,8 +795,13 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 
 void __init smp_prepare_boot_cpu(void)
 {
-    cpumask_set_cpu(smp_processor_id(), &cpu_online_map);
-    cpumask_set_cpu(smp_processor_id(), &cpu_present_map);
+    int cpu = smp_processor_id();
+    int socket = cpu_to_socket(cpu);
+
+    cpumask_set_cpu(cpu, &cpu_online_map);
+    cpumask_set_cpu(cpu, &cpu_present_map);
+    if ( socket >= 0 )
+        cpumask_set_cpu(cpu, &socket_cpu_map[socket]);
 }
 
 static void
@@ -819,6 +831,7 @@ remove_siblinginfo(int cpu)
 void __cpu_disable(void)
 {
     int cpu = smp_processor_id();
+    int socket = cpu_to_socket(cpu);
 
     set_cpu_state(CPU_STATE_DYING);
 
@@ -836,6 +849,8 @@ void __cpu_disable(void)
     /* It's now safe to remove this processor from the online map */
     cpumask_clear_cpu(cpu, cpupool0->cpu_valid);
     cpumask_clear_cpu(cpu, &cpu_online_map);
+    if ( socket >= 0 )
+        cpumask_clear_cpu(cpu, &socket_cpu_map[socket]);
     fixup_irqs();
 
     if ( cpu_disable_scheduler(cpu) )
diff --git a/xen/include/asm-x86/smp.h b/xen/include/asm-x86/smp.h
index 81f8610..f47fa1b 100644
--- a/xen/include/asm-x86/smp.h
+++ b/xen/include/asm-x86/smp.h
@@ -57,6 +57,8 @@ int hard_smp_processor_id(void);
 
 void __stop_this_cpu(void);
 
+#define MAX_NUM_SOCKETS 256
+
 #endif /* !__ASSEMBLY__ */
 
 #endif
diff --git a/xen/include/xen/cpumask.h b/xen/include/xen/cpumask.h
index 850b4a2..883a52a 100644
--- a/xen/include/xen/cpumask.h
+++ b/xen/include/xen/cpumask.h
@@ -419,6 +419,7 @@ static inline void free_cpumask_var(cpumask_var_t mask)
 extern cpumask_t cpu_possible_map;
 extern cpumask_t cpu_online_map;
 extern cpumask_t cpu_present_map;
+extern cpumask_t socket_cpu_map[];
 
 #if NR_CPUS > 1
 #define num_online_cpus()      cpumask_weight(&cpu_online_map)
-- 
1.7.9.5


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