[PATCH] sched: cpu_sibling_map to cpu_mask

From: Nick Piggin <piggin@cyberone.com.au>

This is a (somewhat) trivial patch which converts cpu_sibling_map from an
array of CPUs to an array of cpumasks.  Needed for >2 siblings per package,
but it actually can simplify code as it allows the cpu_sibling_map to be
set up even when there is 1 sibling per package.  Intel want this, I use it
in the next patch to build scheduling domains for the P4 HT.

From: Thomas Schlichter <thomas.schlichter@web.de>

   Build fix

From: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>

   Fix to handle more than 2 siblings per package.

diff --git a/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c b/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c
index 28d5e2243017a658489510db5346909e88fbc9f3..6e414b6a990d473872ca7e0a8a393a6e696acd1b 100644 (file)
--- a/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c
+++ b/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c
@@ -57,8 +57,7 @@ static int cpufreq_p4_setdc(unsigned int cpu, unsigned int newstate)
        u32 l, h;
        cpumask_t cpus_allowed, affected_cpu_map;
        struct cpufreq_freqs freqs;
-       int hyperthreading = 0;
-       int sibling = 0;
+       int j;
 
        if (!cpu_online(cpu) || (newstate > DC_DISABLE) || 
                (newstate == DC_RESV))
@@ -68,13 +67,10 @@ static int cpufreq_p4_setdc(unsigned int cpu, unsigned int newstate)
        cpus_allowed = current->cpus_allowed;
 
        /* only run on CPU to be set, or on its sibling */
-       affected_cpu_map = cpumask_of_cpu(cpu);
-#ifdef CONFIG_X86_HT
-       hyperthreading = ((cpu_has_ht) && (smp_num_siblings == 2));
-       if (hyperthreading) {
-               sibling = cpu_sibling_map[cpu];
-                cpu_set(sibling, affected_cpu_map);
-       }
+#ifdef CONFIG_SMP
+       affected_cpu_map = cpu_sibling_map[cpu];
+#else
+       affected_cpu_map = cpumask_of_cpu(cpu);
 #endif
        set_cpus_allowed(current, affected_cpu_map);
         BUG_ON(!cpu_isset(smp_processor_id(), affected_cpu_map));
@@ -97,11 +93,11 @@ static int cpufreq_p4_setdc(unsigned int cpu, unsigned int newstate)
        /* notifiers */
        freqs.old = stock_freq * l / 8;
        freqs.new = stock_freq * newstate / 8;
-       freqs.cpu = cpu;
-       cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
-       if (hyperthreading) {
-               freqs.cpu = sibling;
-               cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+       for_each_cpu(j) {
+               if (cpu_isset(j, affected_cpu_map)) {
+                       freqs.cpu = j;
+                       cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+               }
        }
 
        rdmsr(MSR_IA32_THERM_STATUS, l, h);
@@ -132,10 +128,11 @@ static int cpufreq_p4_setdc(unsigned int cpu, unsigned int newstate)
        set_cpus_allowed(current, cpus_allowed);
 
        /* notifiers */
-       cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
-       if (hyperthreading) {
-               freqs.cpu = cpu;
-               cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+       for_each_cpu(j) {
+               if (cpu_isset(j, affected_cpu_map)) {
+                       freqs.cpu = j;
+                       cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+               }
        }
 
        return 0;

diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index 92bf30a0bcb183464ebc5701361838c417a9ee5f..d17fa1891238fd05b058626cc59fc13e3fd79652 100644 (file)
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -317,8 +317,7 @@ struct irq_cpu_info {
 
 #define IRQ_ALLOWED(cpu, allowed_mask) cpu_isset(cpu, allowed_mask)
 
-#define CPU_TO_PACKAGEINDEX(i) \
-               ((physical_balance && i > cpu_sibling_map[i]) ? cpu_sibling_map[i] : i)
+#define CPU_TO_PACKAGEINDEX(i) (first_cpu(cpu_sibling_map[i]))
 
 #define MAX_BALANCED_IRQ_INTERVAL      (5*HZ)
 #define MIN_BALANCED_IRQ_INTERVAL      (HZ/2)
@@ -401,6 +400,7 @@ static void do_irq_balance(void)
        unsigned long max_cpu_irq = 0, min_cpu_irq = (~0);
        unsigned long move_this_load = 0;
        int max_loaded = 0, min_loaded = 0;
+       int load;
        unsigned long useful_load_threshold = balanced_irq_interval + 10;
        int selected_irq;
        int tmp_loaded, first_attempt = 1;
@@ -452,7 +452,7 @@ static void do_irq_balance(void)
        for (i = 0; i < NR_CPUS; i++) {
                if (!cpu_online(i))
                        continue;
-               if (physical_balance && i > cpu_sibling_map[i])
+               if (i != CPU_TO_PACKAGEINDEX(i))
                        continue;
                if (min_cpu_irq > CPU_IRQ(i)) {
                        min_cpu_irq = CPU_IRQ(i);
@@ -471,7 +471,7 @@ tryanothercpu:
        for (i = 0; i < NR_CPUS; i++) {
                if (!cpu_online(i))
                        continue;
-               if (physical_balance && i > cpu_sibling_map[i])
+               if (i != CPU_TO_PACKAGEINDEX(i))
                        continue;
                if (max_cpu_irq <= CPU_IRQ(i)) 
                        continue;
@@ -551,9 +551,14 @@ tryanotherirq:
         * We seek the least loaded sibling by making the comparison
         * (A+B)/2 vs B
         */
-       if (physical_balance && (CPU_IRQ(min_loaded) >> 1) >
-                                       CPU_IRQ(cpu_sibling_map[min_loaded]))
-               min_loaded = cpu_sibling_map[min_loaded];
+       load = CPU_IRQ(min_loaded) >> 1;
+       for_each_cpu_mask(j, cpu_sibling_map[min_loaded]) {
+               if (load > CPU_IRQ(j)) {
+                       /* This won't change cpu_sibling_map[min_loaded] */
+                       load = CPU_IRQ(j);
+                       min_loaded = j;
+               }
+       }
 
        cpus_and(allowed_mask, cpu_online_map, irq_affinity[selected_irq]);
        target_cpu_mask = cpumask_of_cpu(min_loaded);

diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index 7baa4d420b730c8d1e2dcf6d2e03920066213266..77d4309d6c6ea97b4c926e77dce2f74a1db578e0 100644 (file)
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -936,7 +936,7 @@ static int boot_cpu_logical_apicid;
 /* Where the IO area was mapped on multiquad, always 0 otherwise */
 void *xquad_portio;
 
-int cpu_sibling_map[NR_CPUS] __cacheline_aligned;
+cpumask_t cpu_sibling_map[NR_CPUS] __cacheline_aligned;
 
 static void __init smp_boot_cpus(unsigned int max_cpus)
 {
@@ -1081,32 +1081,34 @@ static void __init smp_boot_cpus(unsigned int max_cpus)
        Dprintk("Boot done.\n");
 
        /*
-        * If Hyper-Threading is avaialble, construct cpu_sibling_map[], so
-        * that we can tell the sibling CPU efficiently.
+        * construct cpu_sibling_map[], so that we can tell sibling CPUs
+        * efficiently.
         */
-       if (cpu_has_ht && smp_num_siblings > 1) {
-               for (cpu = 0; cpu < NR_CPUS; cpu++)
-                       cpu_sibling_map[cpu] = NO_PROC_ID;
-               
-               for (cpu = 0; cpu < NR_CPUS; cpu++) {
-                       int     i;
-                       if (!cpu_isset(cpu, cpu_callout_map))
-                               continue;
+       for (cpu = 0; cpu < NR_CPUS; cpu++)
+               cpu_sibling_map[cpu] = CPU_MASK_NONE;
+
+       for (cpu = 0; cpu < NR_CPUS; cpu++) {
+               int siblings = 0;
+               int i;
+               if (!cpu_isset(cpu, cpu_callout_map))
+                       continue;
 
+               if (smp_num_siblings > 1) {
                        for (i = 0; i < NR_CPUS; i++) {
-                               if (i == cpu || !cpu_isset(i, cpu_callout_map))
+                               if (!cpu_isset(i, cpu_callout_map))
                                        continue;
                                if (phys_proc_id[cpu] == phys_proc_id[i]) {
-                                       cpu_sibling_map[cpu] = i;
-                                       printk("cpu_sibling_map[%d] = %d\n", cpu, cpu_sibling_map[cpu]);
-                                       break;
+                                       siblings++;
+                                       cpu_set(i, cpu_sibling_map[cpu]);
                                }
                        }
-                       if (cpu_sibling_map[cpu] == NO_PROC_ID) {
-                               smp_num_siblings = 1;
-                               printk(KERN_WARNING "WARNING: No sibling found for CPU %d.\n", cpu);
-                       }
+               } else {
+                       siblings++;
+                       cpu_set(cpu, cpu_sibling_map[cpu]);
                }
+
+               if (siblings != smp_num_siblings)
+                       printk(KERN_WARNING "WARNING: %d siblings found for CPU%d, should be %d\n", siblings, cpu, smp_num_siblings);
        }
 
        smpboot_setup_io_apic();

diff --git a/arch/i386/oprofile/op_model_p4.c b/arch/i386/oprofile/op_model_p4.c
index 7e41dc9826a1fb0b41101a539f4440d3d7c6523e..8b932b1b3f143deaebfcbbabf0cc9a8cd8da4408 100644 (file)
--- a/arch/i386/oprofile/op_model_p4.c
+++ b/arch/i386/oprofile/op_model_p4.c
@@ -382,11 +382,8 @@ static struct p4_event_binding p4_events[NUM_EVENTS] = {
 static unsigned int get_stagger(void)
 {
 #ifdef CONFIG_SMP
-       int cpu;
-       if (smp_num_siblings > 1) {
-               cpu = smp_processor_id();
-               return (cpu_sibling_map[cpu] > cpu) ? 0 : 1;
-       }
+       int cpu = smp_processor_id();
+       return (cpu != first_cpu(cpu_sibling_map[cpu]));
 #endif 
        return 0;
 }

diff --git a/include/asm-i386/smp.h b/include/asm-i386/smp.h
index 268dabd466532c232f06f1e450f9a6f67c7d3aa0..88c461e5e1073f5fa20e6df9ba6d3194238737e1 100644 (file)
--- a/include/asm-i386/smp.h
+++ b/include/asm-i386/smp.h
@@ -34,7 +34,7 @@
 extern void smp_alloc_memory(void);
 extern int pic_mode;
 extern int smp_num_siblings;
-extern int cpu_sibling_map[];
+extern cpumask_t cpu_sibling_map[];
 
 extern void smp_flush_tlb(void);
 extern void smp_message_irq(int cpl, void *dev_id, struct pt_regs *regs);