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linux/arch/x86/kernel/cpu/proc.c

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#include <linux/smp.h>
#include <linux/timex.h>
#include <linux/string.h>
#include <linux/seq_file.h>
/*
* Get CPU information for use by the procfs.
*/
static void show_cpuinfo_core(struct seq_file *m, struct cpuinfo_x86 *c,
unsigned int cpu)
{
#ifdef CONFIG_SMP
x86/cpu: Always print SMP information in /proc/cpuinfo Currently show_cpuinfo_core() displays cpu core information only if the number of threads per a whole cores is 2 or larger. However, this condition doesn't care about the number of sockets. For example, this condition doesn't hold on systems with two logical cpus consisting of two sockets and a single core on each socket - yet the topology information would be interesting to see in that case as well. I don't know whether or not there are processors in real world by which such configurations are possible, but at least on vitual machine environments, such configuration can occur, typically when no explicit SMP information is provided in advance. For example, on qemu/KVM, SMP information is specified via -smp command-line option, more specifically, its syntax is: -smp n[,cores=cores][,threads=threads][,sockets=sockets][,maxcpus=maxcpus] If this is not specified, qemu tells configuration with n-sockets, 1-core and 1-thread to the guest machine, on which guest, MP information is not displayed in /proc/cpuinfo. I saw this situation on VMWare guest environment, too. To fix this issue, this patch simply removes the condition because this information is useful even if there's only 1 thread. Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/5277D644.4090707@jp.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-04 10:15:48 -07:00
seq_printf(m, "physical id\t: %d\n", c->phys_proc_id);
seq_printf(m, "siblings\t: %d\n",
cpumask_weight(topology_core_cpumask(cpu)));
x86/cpu: Always print SMP information in /proc/cpuinfo Currently show_cpuinfo_core() displays cpu core information only if the number of threads per a whole cores is 2 or larger. However, this condition doesn't care about the number of sockets. For example, this condition doesn't hold on systems with two logical cpus consisting of two sockets and a single core on each socket - yet the topology information would be interesting to see in that case as well. I don't know whether or not there are processors in real world by which such configurations are possible, but at least on vitual machine environments, such configuration can occur, typically when no explicit SMP information is provided in advance. For example, on qemu/KVM, SMP information is specified via -smp command-line option, more specifically, its syntax is: -smp n[,cores=cores][,threads=threads][,sockets=sockets][,maxcpus=maxcpus] If this is not specified, qemu tells configuration with n-sockets, 1-core and 1-thread to the guest machine, on which guest, MP information is not displayed in /proc/cpuinfo. I saw this situation on VMWare guest environment, too. To fix this issue, this patch simply removes the condition because this information is useful even if there's only 1 thread. Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/5277D644.4090707@jp.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-04 10:15:48 -07:00
seq_printf(m, "core id\t\t: %d\n", c->cpu_core_id);
seq_printf(m, "cpu cores\t: %d\n", c->booted_cores);
seq_printf(m, "apicid\t\t: %d\n", c->apicid);
seq_printf(m, "initial apicid\t: %d\n", c->initial_apicid);
#endif
}
#ifdef CONFIG_X86_32
static void show_cpuinfo_misc(struct seq_file *m, struct cpuinfo_x86 *c)
{
seq_printf(m,
"fdiv_bug\t: %s\n"
"f00f_bug\t: %s\n"
"coma_bug\t: %s\n"
"fpu\t\t: %s\n"
"fpu_exception\t: %s\n"
"cpuid level\t: %d\n"
x86/cpu: Drop wp_works_ok member of struct cpuinfo_x86 Remove the wp_works_ok member of struct cpuinfo_x86. It's an optimization back from Linux v0.99 times where we had no fixup support yet and did the CR0.WP test via special code in the page fault handler. The < 0 test was an optimization to not do the special casing for each NULL ptr access violation but just for the first one doing the WP test. Today it serves no real purpose as the test no longer needs special code in the page fault handler and the only call side -- mem_init() -- calls it just once, anyway. However, Xen pre-initializes it to 1, to skip the test. Doing the test again for Xen should be no issue at all, as even the commit introducing skipping the test (commit d560bc61575e ("x86, xen: Suppress WP test on Xen")) mentioned it being ban aid only. And, in fact, testing the patch on Xen showed nothing breaks. The pre-fixup times are long gone and with the removal of the fallback handling code in commit a5c2a893dbd4 ("x86, 386 removal: Remove CONFIG_X86_WP_WORKS_OK") the kernel requires a working CR0.WP anyway. So just get rid of the "optimization" and do the test unconditionally. Signed-off-by: Mathias Krause <minipli@googlemail.com> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Arnd Hannemann <hannemann@nets.rwth-aachen.de> Cc: Mikael Starvik <starvik@axis.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: "David S. Miller" <davem@davemloft.net> Link: http://lkml.kernel.org/r/1486933932-585-3-git-send-email-minipli@googlemail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-02-12 14:12:08 -07:00
"wp\t\t: yes\n",
static_cpu_has_bug(X86_BUG_FDIV) ? "yes" : "no",
static_cpu_has_bug(X86_BUG_F00F) ? "yes" : "no",
static_cpu_has_bug(X86_BUG_COMA) ? "yes" : "no",
static_cpu_has(X86_FEATURE_FPU) ? "yes" : "no",
static_cpu_has(X86_FEATURE_FPU) ? "yes" : "no",
x86/cpu: Drop wp_works_ok member of struct cpuinfo_x86 Remove the wp_works_ok member of struct cpuinfo_x86. It's an optimization back from Linux v0.99 times where we had no fixup support yet and did the CR0.WP test via special code in the page fault handler. The < 0 test was an optimization to not do the special casing for each NULL ptr access violation but just for the first one doing the WP test. Today it serves no real purpose as the test no longer needs special code in the page fault handler and the only call side -- mem_init() -- calls it just once, anyway. However, Xen pre-initializes it to 1, to skip the test. Doing the test again for Xen should be no issue at all, as even the commit introducing skipping the test (commit d560bc61575e ("x86, xen: Suppress WP test on Xen")) mentioned it being ban aid only. And, in fact, testing the patch on Xen showed nothing breaks. The pre-fixup times are long gone and with the removal of the fallback handling code in commit a5c2a893dbd4 ("x86, 386 removal: Remove CONFIG_X86_WP_WORKS_OK") the kernel requires a working CR0.WP anyway. So just get rid of the "optimization" and do the test unconditionally. Signed-off-by: Mathias Krause <minipli@googlemail.com> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Arnd Hannemann <hannemann@nets.rwth-aachen.de> Cc: Mikael Starvik <starvik@axis.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: "David S. Miller" <davem@davemloft.net> Link: http://lkml.kernel.org/r/1486933932-585-3-git-send-email-minipli@googlemail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-02-12 14:12:08 -07:00
c->cpuid_level);
}
#else
static void show_cpuinfo_misc(struct seq_file *m, struct cpuinfo_x86 *c)
{
seq_printf(m,
"fpu\t\t: yes\n"
"fpu_exception\t: yes\n"
"cpuid level\t: %d\n"
"wp\t\t: yes\n",
c->cpuid_level);
}
#endif
static int show_cpuinfo(struct seq_file *m, void *v)
{
struct cpuinfo_x86 *c = v;
unsigned int cpu;
int i;
cpu = c->cpu_index;
seq_printf(m, "processor\t: %u\n"
"vendor_id\t: %s\n"
"cpu family\t: %d\n"
"model\t\t: %u\n"
"model name\t: %s\n",
cpu,
c->x86_vendor_id[0] ? c->x86_vendor_id : "unknown",
c->x86,
c->x86_model,
c->x86_model_id[0] ? c->x86_model_id : "unknown");
if (c->x86_mask || c->cpuid_level >= 0)
seq_printf(m, "stepping\t: %d\n", c->x86_mask);
else
seq_puts(m, "stepping\t: unknown\n");
if (c->microcode)
seq_printf(m, "microcode\t: 0x%x\n", c->microcode);
x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz" cpufreq_quick_get() allows cpufreq drivers to over-ride cpu_khz that is otherwise reported in x86 /proc/cpuinfo "cpu MHz". There are four problems with this scheme, any of them is sufficient justification to delete it. 1. Depending on which cpufreq driver is loaded, the behavior of this field is different. 2. Distros complain that they have to explain to users why and how this field changes. Distros have requested a constant. 3. The two major providers of this information, acpi_cpufreq and intel_pstate, both "get it wrong" in different ways. acpi_cpufreq lies to the user by telling them that they are running at whatever frequency was last requested by software. intel_pstate lies to the user by telling them that they are running at the average frequency computed over an undefined measurement. But an average computed over an undefined interval, is itself, undefined... 4. On modern processors, user space utilities, such as turbostat(1), are more accurate and more precise, while supporing concurrent measurement over arbitrary intervals. Users who have been consulting /proc/cpuinfo to track changing CPU frequency will be dissapointed that it no longer wiggles -- perhaps being unaware of the limitations of the information they have been consuming. Yes, they can change their scripts to look in sysfs cpufreq/scaling_cur_frequency. Here they will find the same data of dubious quality here removed from /proc/cpuinfo. The value in sysfs will be addressed in a subsequent patch to address issues 1-3, above. Issue 4 will remain -- users that really care about accurate frequency information should not be using either proc or sysfs kernel interfaces. They should be using using turbostat(8), or a similar purpose-built analysis tool. Signed-off-by: Len Brown <len.brown@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-16 20:03:11 -07:00
if (cpu_has(c, X86_FEATURE_TSC))
seq_printf(m, "cpu MHz\t\t: %u.%03u\n",
x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz" cpufreq_quick_get() allows cpufreq drivers to over-ride cpu_khz that is otherwise reported in x86 /proc/cpuinfo "cpu MHz". There are four problems with this scheme, any of them is sufficient justification to delete it. 1. Depending on which cpufreq driver is loaded, the behavior of this field is different. 2. Distros complain that they have to explain to users why and how this field changes. Distros have requested a constant. 3. The two major providers of this information, acpi_cpufreq and intel_pstate, both "get it wrong" in different ways. acpi_cpufreq lies to the user by telling them that they are running at whatever frequency was last requested by software. intel_pstate lies to the user by telling them that they are running at the average frequency computed over an undefined measurement. But an average computed over an undefined interval, is itself, undefined... 4. On modern processors, user space utilities, such as turbostat(1), are more accurate and more precise, while supporing concurrent measurement over arbitrary intervals. Users who have been consulting /proc/cpuinfo to track changing CPU frequency will be dissapointed that it no longer wiggles -- perhaps being unaware of the limitations of the information they have been consuming. Yes, they can change their scripts to look in sysfs cpufreq/scaling_cur_frequency. Here they will find the same data of dubious quality here removed from /proc/cpuinfo. The value in sysfs will be addressed in a subsequent patch to address issues 1-3, above. Issue 4 will remain -- users that really care about accurate frequency information should not be using either proc or sysfs kernel interfaces. They should be using using turbostat(8), or a similar purpose-built analysis tool. Signed-off-by: Len Brown <len.brown@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-16 20:03:11 -07:00
cpu_khz / 1000, (cpu_khz % 1000));
/* Cache size */
if (c->x86_cache_size >= 0)
seq_printf(m, "cache size\t: %d KB\n", c->x86_cache_size);
show_cpuinfo_core(m, c, cpu);
show_cpuinfo_misc(m, c);
seq_puts(m, "flags\t\t:");
for (i = 0; i < 32*NCAPINTS; i++)
if (cpu_has(c, i) && x86_cap_flags[i] != NULL)
seq_printf(m, " %s", x86_cap_flags[i]);
seq_puts(m, "\nbugs\t\t:");
for (i = 0; i < 32*NBUGINTS; i++) {
unsigned int bug_bit = 32*NCAPINTS + i;
if (cpu_has_bug(c, bug_bit) && x86_bug_flags[i])
seq_printf(m, " %s", x86_bug_flags[i]);
}
seq_printf(m, "\nbogomips\t: %lu.%02lu\n",
c->loops_per_jiffy/(500000/HZ),
(c->loops_per_jiffy/(5000/HZ)) % 100);
#ifdef CONFIG_X86_64
if (c->x86_tlbsize > 0)
seq_printf(m, "TLB size\t: %d 4K pages\n", c->x86_tlbsize);
#endif
seq_printf(m, "clflush size\t: %u\n", c->x86_clflush_size);
seq_printf(m, "cache_alignment\t: %d\n", c->x86_cache_alignment);
seq_printf(m, "address sizes\t: %u bits physical, %u bits virtual\n",
c->x86_phys_bits, c->x86_virt_bits);
seq_puts(m, "power management:");
for (i = 0; i < 32; i++) {
if (c->x86_power & (1 << i)) {
if (i < ARRAY_SIZE(x86_power_flags) &&
x86_power_flags[i])
seq_printf(m, "%s%s",
x86_power_flags[i][0] ? " " : "",
x86_power_flags[i]);
else
seq_printf(m, " [%d]", i);
}
}
seq_puts(m, "\n\n");
return 0;
}
static void *c_start(struct seq_file *m, loff_t *pos)
{
*pos = cpumask_next(*pos - 1, cpu_online_mask);
if ((*pos) < nr_cpu_ids)
return &cpu_data(*pos);
return NULL;
}
static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
(*pos)++;
return c_start(m, pos);
}
static void c_stop(struct seq_file *m, void *v)
{
}
const struct seq_operations cpuinfo_op = {
.start = c_start,
.next = c_next,
.stop = c_stop,
.show = show_cpuinfo,
};