[PATCH] x86_64: Limit the number of processor bootup messages

From: Mike Travis
Date: Fri Oct 30 2009 - 15:25:26 EST


x86_64: Limit the number of processor bootup messages

With a large number of processors in a system there is an excessive amount
of messages sent to the system console. It's estimated that with 4096
processors in a system, and the console baudrate set to 56K, the startup
messages will take about 84 minutes to clear the serial port.

This set of patches limits the number of repetitious messages which contain
no additional information. Much of this information is obtainable from the
/proc and /sysfs. Most of the messages are also sent to the kernel log
buffer as KERN_DEBUG messages so it can be used to examine more closely any
details specific to a processor.

The list of message transformations....

For system_state == SYSTEM_BOOTING:

[ 25.388280] Booting Processors 1-7,320-327, Node 0
[ 26.064742] Booting Processors 8-15,328-335, Node 1
[ 26.837006] Booting Processors 16-31,336-351, Nodes 2-3
[ 28.440427] Booting Processors 32-63,352-383, Nodes 4-7
[ 31.640450] Booting Processors 64-127,384-447, Nodes 8-15
[ 38.041430] Booting Processors 128-255,448-575, Nodes 16-31
[ 50.917504] Booting Processors 256-319,576-639, Nodes 32-39
[ 90.964169] Brought up 640 CPUs

The range of processors increases as a power of 2, so 4096 CPU's should
only take 12 lines.

(QUESTION: print_summary_bootmsg() is in the __init section and is called
from a __cpuinit function, but only when system is booting. Is there a
special flag to handle this case?)

For Processor Information printout:

[ 90.968381] Summary Processor Information for CPUS: 0-639
[ 90.972033] Genuine Intel(R) CPU 0000 @ 2.13GHz stepping 04
[ 90.981402] CPU: L1 I cache: 32K, L1 D cache: 32K
[ 90.985888] CPU: L2 cache: 256K
[ 90.988032] CPU: L3 cache: 24576K
[ 90.992032] MIN 4266.68 BogoMIPS (lpj=8533371)
[ 91.000033] MAX 4267.89 BogoMIPS (lpj=8535789)

These lines have been moved to loglevel KERN_DEBUG:

CPU: Physical Processor ID:
CPU: Processor Core ID:
CPU %d/0x%x -> Node %d
<cache line sizes per cpu>
CPUx is down

This message has been changed to loglevel KERN_DEBUG if system is booting
and KERN_INFO otherwise:

CPU %d is now offline

Signed-off-by: Mike Travis <travis@xxxxxxx>
---
arch/x86/include/asm/processor.h | 4 arch/x86/kernel/cpu/addon_cpuid_features.c | 4 arch/x86/kernel/cpu/amd.c | 2 arch/x86/kernel/cpu/common.c | 23 +++-
arch/x86/kernel/cpu/intel.c | 2 arch/x86/kernel/cpu/intel_cacheinfo.c | 22 +---
arch/x86/kernel/smpboot.c | 154 ++++++++++++++++++++++++++++-
kernel/cpu.c | 2 8 files changed, 187 insertions(+), 26 deletions(-)

--- linux.orig/arch/x86/include/asm/processor.h
+++ linux/arch/x86/include/asm/processor.h
@@ -111,6 +111,9 @@
u16 cpu_core_id;
/* Index into per_cpu list: */
u16 cpu_index;
+ /* Interior Cache Sizes: */
+ u16 l1i, l1d, l2;
+ u32 l3;
#endif
unsigned int x86_hyper_vendor;
} __attribute__((__aligned__(SMP_CACHE_BYTES)));
@@ -169,6 +172,7 @@
extern void identify_boot_cpu(void);
extern void identify_secondary_cpu(struct cpuinfo_x86 *);
extern void print_cpu_info(struct cpuinfo_x86 *);
+extern void print_cache_info(struct cpuinfo_x86 *, char *msglvl);
extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c);
extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
extern unsigned short num_cache_leaves;
--- linux.orig/arch/x86/kernel/cpu/addon_cpuid_features.c
+++ linux/arch/x86/kernel/cpu/addon_cpuid_features.c
@@ -128,10 +128,10 @@
c->x86_max_cores = (core_level_siblings / smp_num_siblings);


- printk(KERN_INFO "CPU: Physical Processor ID: %d\n",
+ printk(KERN_DEBUG "CPU: Physical Processor ID: %d\n",
c->phys_proc_id);
if (c->x86_max_cores > 1)
- printk(KERN_INFO "CPU: Processor Core ID: %d\n",
+ printk(KERN_DEBUG "CPU: Processor Core ID: %d\n",
c->cpu_core_id);
return;
#endif
--- linux.orig/arch/x86/kernel/cpu/amd.c
+++ linux/arch/x86/kernel/cpu/amd.c
@@ -376,7 +376,7 @@
}
numa_set_node(cpu, node);

- printk(KERN_INFO "CPU %d/0x%x -> Node %d\n", cpu, apicid, node);
+ printk(KERN_DEBUG "CPU %d/0x%x -> Node %d\n", cpu, apicid, node);
#endif
}

--- linux.orig/arch/x86/kernel/cpu/common.c
+++ linux/arch/x86/kernel/cpu/common.c
@@ -475,9 +475,9 @@

out:
if ((c->x86_max_cores * smp_num_siblings) > 1) {
- printk(KERN_INFO "CPU: Physical Processor ID: %d\n",
+ printk(KERN_DEBUG "CPU: Physical Processor ID: %d\n",
c->phys_proc_id);
- printk(KERN_INFO "CPU: Processor Core ID: %d\n",
+ printk(KERN_DEBUG "CPU: Processor Core ID: %d\n",
c->cpu_core_id);
}
#endif
@@ -967,6 +967,23 @@
#endif
}

+void __cpuinit print_cache_info(struct cpuinfo_x86 *c, char *lvl)
+{
+ if (c->l1i)
+ printk("%sCPU: L1 I cache: %dK", lvl, c->l1i);
+
+ if (c->l1d)
+ printk(KERN_CONT ", L1 D cache: %dK\n", c->l1d);
+ else
+ printk(KERN_CONT "\n");
+
+ if (c->l2)
+ printk("%sCPU: L2 cache: %dK\n", lvl, c->l2);
+
+ if (c->l3)
+ printk("%sCPU: L3 cache: %dK\n", lvl, c->l3);
+}
+
static __init int setup_disablecpuid(char *arg)
{
int bit;
@@ -1115,7 +1132,7 @@
if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask))
panic("CPU#%d already initialized!\n", cpu);

- printk(KERN_INFO "Initializing CPU#%d\n", cpu);
+ printk(KERN_DEBUG "Initializing CPU#%d\n", cpu);

clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);

--- linux.orig/arch/x86/kernel/cpu/intel.c
+++ linux/arch/x86/kernel/cpu/intel.c
@@ -267,7 +267,7 @@
node = first_node(node_online_map);
numa_set_node(cpu, node);

- printk(KERN_INFO "CPU %d/0x%x -> Node %d\n", cpu, apicid, node);
+ printk(KERN_DEBUG "CPU %d/0x%x -> Node %d\n", cpu, apicid, node);
#endif
}

--- linux.orig/arch/x86/kernel/cpu/intel_cacheinfo.c
+++ linux/arch/x86/kernel/cpu/intel_cacheinfo.c
@@ -489,23 +489,17 @@
}

if (trace)
- printk(KERN_INFO "CPU: Trace cache: %dK uops", trace);
- else if (l1i)
- printk(KERN_INFO "CPU: L1 I cache: %dK", l1i);
-
- if (l1d)
- printk(KERN_CONT ", L1 D cache: %dK\n", l1d);
- else
- printk(KERN_CONT "\n");
-
- if (l2)
- printk(KERN_INFO "CPU: L2 cache: %dK\n", l2);
-
- if (l3)
- printk(KERN_INFO "CPU: L3 cache: %dK\n", l3);
+ printk(KERN_DEBUG "CPU: Trace cache: %dK uops", trace);

+ c->l1i = l1i;
+ c->l1d = l1d;
+ c->l2 = l2;
+ c->l3 = l3;
c->x86_cache_size = l3 ? l3 : (l2 ? l2 : (l1i+l1d));

+ print_cache_info(c,
+ system_state == SYSTEM_BOOTING? KERN_DEBUG : KERN_INFO);
+
return l2;
}

--- linux.orig/arch/x86/kernel/smpboot.c
+++ linux/arch/x86/kernel/smpboot.c
@@ -442,6 +442,94 @@
return c->llc_shared_map;
}

+/* Summarize Processor Information */
+static void __init summarize_cpu_info(void)
+{
+ cpumask_var_t cpulist, cpusdone;
+ int cpu;
+ int err = 0;
+
+ if (!alloc_cpumask_var(&cpulist, GFP_KERNEL))
+ err = 1;
+
+ else if (!alloc_cpumask_var(&cpusdone, GFP_KERNEL)) {
+ free_cpumask_var(cpulist);
+ err = 1;
+ }
+
+ if (err) {
+ printk(KERN_INFO "Can't print processor summaries\n");
+ return;
+ }
+
+ cpumask_clear(cpusdone);
+ for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
+ struct cpuinfo_x86 *c;
+ int l1i, l1d, l2, l3;
+ int x86, x86_vendor, x86_model, x86_mask;
+ char buf[64];
+ int ncpu;
+ unsigned long minlpj, maxlpj;
+
+ /* skip if cpu has already been displayed */
+ if (cpumask_test_cpu(cpu, cpusdone))
+ continue;
+
+ c = &cpu_data(cpu);
+ l1i = c->l1i;
+ l1d = c->l1d;
+ l2 = c->l2;
+ l3 = c->l3;
+ x86 = c->x86;
+ x86_vendor = c->x86_vendor;
+ x86_model = c->x86_model;
+ x86_mask = c->x86_mask;
+ minlpj = ULONG_MAX;
+ maxlpj = 0;
+
+ cpumask_clear(cpulist);
+
+ /* collate all cpus with same specifics */
+ for (ncpu = cpu; ncpu < nr_cpu_ids; ncpu++) {
+ if (l1i != cpu_data(ncpu).l1i ||
+ l1d != cpu_data(ncpu).l1d ||
+ l2 != cpu_data(ncpu).l2 ||
+ l3 != cpu_data(ncpu).l3 ||
+ x86 != cpu_data(ncpu).x86 ||
+ x86_vendor != cpu_data(ncpu).x86_vendor ||
+ x86_model != cpu_data(ncpu).x86_model ||
+ x86_mask != cpu_data(ncpu).x86_mask)
+ continue;
+
+ cpumask_set_cpu(ncpu, cpulist);
+ cpumask_set_cpu(ncpu, cpusdone);
+
+ if (cpu_data(ncpu).loops_per_jiffy < minlpj)
+ minlpj = cpu_data(ncpu).loops_per_jiffy;
+
+ if (cpu_data(ncpu).loops_per_jiffy > maxlpj)
+ maxlpj = cpu_data(ncpu).loops_per_jiffy;
+ }
+
+ cpulist_scnprintf(buf, sizeof(buf), cpulist);
+ printk(KERN_INFO
+ "Summary Processor Information for CPUS: %s\n", buf);
+
+ printk(KERN_INFO);
+ print_cpu_info(c);
+ print_cache_info(c, KERN_INFO);
+
+ printk(KERN_INFO "MIN %lu.%02lu BogoMIPS (lpj=%lu)\n",
+ minlpj/(500000/HZ), (minlpj/(5000/HZ)) % 100, minlpj);
+
+ printk(KERN_INFO "MAX %lu.%02lu BogoMIPS (lpj=%lu)\n",
+ maxlpj/(500000/HZ), (maxlpj/(5000/HZ)) % 100, maxlpj);
+ }
+
+ free_cpumask_var(cpusdone);
+ free_cpumask_var(cpulist);
+}
+
static void impress_friends(void)
{
int cpu;
@@ -671,6 +759,50 @@
complete(&c_idle->done);
}

+/* Summarize the "Booting processor ..." startup messages */
+static void __init print_summary_bootmsg(int cpu)
+{
+ static int next_node, node_shift;
+ int node = cpu_to_node(cpu);
+
+ if (node >= next_node) {
+ cpumask_var_t cpulist;
+
+ node = next_node;
+ next_node = 1 << node_shift;
+ node_shift++;
+
+ if (alloc_cpumask_var(&cpulist, GFP_KERNEL)) {
+ int i, tmp, last_node = node;
+ char buf[32];
+
+ cpumask_clear(cpulist);
+ for_each_present_cpu(i) {
+ if (i == 0) /* boot cpu */
+ continue;
+
+ tmp = cpu_to_node(i);
+ if (node <= tmp && tmp < next_node) {
+ cpumask_set_cpu(i, cpulist);
+ if (last_node < tmp)
+ last_node = tmp;
+ }
+ }
+ if (cpumask_weight(cpulist)) {
+ cpulist_scnprintf(buf, sizeof(buf), cpulist);
+ printk(KERN_INFO "Booting Processors %s,", buf);
+
+ if (node == last_node)
+ printk(KERN_CONT " Node %d\n", node);
+ else
+ printk(KERN_CONT " Nodes %d-%d\n",
+ node, last_node);
+ }
+ free_cpumask_var(cpulist);
+ }
+ }
+}
+
/*
* NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
* (ie clustered apic addressing mode), this is a LOGICAL apic ID.
@@ -737,8 +869,14 @@
start_ip = setup_trampoline();

/* So we see what's up */
- printk(KERN_INFO "Booting processor %d APIC 0x%x ip 0x%lx\n",
- cpu, apicid, start_ip);
+ if (system_state == SYSTEM_BOOTING) {
+ print_summary_bootmsg(cpu);
+ printk(KERN_DEBUG);
+ } else
+ printk(KERN_INFO);
+
+ printk(KERN_CONT "Booting processor %d APIC 0x%x ip 0x%lx\n",
+ cpu, apicid, start_ip);

/*
* This grunge runs the startup process for
@@ -790,7 +928,7 @@
if (cpumask_test_cpu(cpu, cpu_callin_mask)) {
/* number CPUs logically, starting from 1 (BSP is 0) */
pr_debug("OK.\n");
- printk(KERN_INFO "CPU%d: ", cpu);
+ printk(KERN_DEBUG "CPU%d: ", cpu);
print_cpu_info(&cpu_data(cpu));
pr_debug("CPU has booted.\n");
} else {
@@ -1147,6 +1285,9 @@
{
pr_debug("Boot done.\n");

+ /* print processor data summaries */
+ summarize_cpu_info();
+
impress_friends();
#ifdef CONFIG_X86_IO_APIC
setup_ioapic_dest();
@@ -1300,7 +1441,12 @@
for (i = 0; i < 10; i++) {
/* They ack this in play_dead by setting CPU_DEAD */
if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
- printk(KERN_INFO "CPU %d is now offline\n", cpu);
+ if (system_state == SYSTEM_RUNNING)
+ printk(KERN_INFO);
+ else
+ printk(KERN_DEBUG);
+
+ printk(KERN_CONT "CPU %d is now offline\n", cpu);
if (1 == num_online_cpus())
alternatives_smp_switch(0);
return;
--- linux.orig/kernel/cpu.c
+++ linux/kernel/cpu.c
@@ -394,7 +394,7 @@
error = _cpu_down(cpu, 1);
if (!error) {
cpumask_set_cpu(cpu, frozen_cpus);
- printk("CPU%d is down\n", cpu);
+ printk(KERN_DEBUG "CPU%d is down\n", cpu);
} else {
printk(KERN_ERR "Error taking CPU%d down: %d\n",
cpu, error);

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/