tools/power/cpupower/utils/idle_monitor/snb_idle.c
Source file repositories/reference/linux-study-clean/tools/power/cpupower/utils/idle_monitor/snb_idle.c
File Facts
- System
- Linux kernel
- Corpus path
tools/power/cpupower/utils/idle_monitor/snb_idle.c- Extension
.c- Size
- 4590 bytes
- Lines
- 200
- Domain
- Support Tooling And Documentation
- Bucket
- tools
- Inferred role
- Support Tooling And Documentation: implementation source
- Status
- source implementation candidate
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
stdio.hstdint.hstdlib.hstring.hhelpers/helpers.hidle_monitor/cpupower-monitor.h
Detected Declarations
enum intel_snb_idfunction snb_get_countfunction snb_get_count_percentfunction snb_startfunction snb_stopfunction snb_unregister
Annotated Snippet
// SPDX-License-Identifier: GPL-2.0-only
/*
* (C) 2010,2011 Thomas Renninger <trenn@suse.de>, Novell Inc.
*
* Based on Len Brown's <lenb@kernel.org> turbostat tool.
*/
#if defined(__i386__) || defined(__x86_64__)
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "helpers/helpers.h"
#include "idle_monitor/cpupower-monitor.h"
#define MSR_PKG_C2_RESIDENCY 0x60D
#define MSR_PKG_C7_RESIDENCY 0x3FA
#define MSR_CORE_C7_RESIDENCY 0x3FE
#define MSR_TSC 0x10
enum intel_snb_id { C7 = 0, PC2, PC7, SNB_CSTATE_COUNT, TSC = 0xFFFF };
static int snb_get_count_percent(unsigned int self_id, double *percent,
unsigned int cpu);
static cstate_t snb_cstates[SNB_CSTATE_COUNT] = {
{
.name = "C7",
.desc = N_("Processor Core C7"),
.id = C7,
.range = RANGE_CORE,
.get_count_percent = snb_get_count_percent,
},
{
.name = "PC2",
.desc = N_("Processor Package C2"),
.id = PC2,
.range = RANGE_PACKAGE,
.get_count_percent = snb_get_count_percent,
},
{
.name = "PC7",
.desc = N_("Processor Package C7"),
.id = PC7,
.range = RANGE_PACKAGE,
.get_count_percent = snb_get_count_percent,
},
};
static unsigned long long tsc_at_measure_start;
static unsigned long long tsc_at_measure_end;
static unsigned long long *previous_count[SNB_CSTATE_COUNT];
static unsigned long long *current_count[SNB_CSTATE_COUNT];
/* valid flag for all CPUs. If a MSR read failed it will be zero */
static int *is_valid;
static int snb_get_count(enum intel_snb_id id, unsigned long long *val,
unsigned int cpu)
{
int msr;
switch (id) {
case C7:
msr = MSR_CORE_C7_RESIDENCY;
break;
case PC2:
msr = MSR_PKG_C2_RESIDENCY;
break;
case PC7:
msr = MSR_PKG_C7_RESIDENCY;
break;
case TSC:
msr = MSR_TSC;
break;
default:
return -1;
}
if (read_msr(cpu, msr, val))
return -1;
return 0;
}
static int snb_get_count_percent(unsigned int id, double *percent,
unsigned int cpu)
{
*percent = 0.0;
Annotation
- Immediate include surface: `stdio.h`, `stdint.h`, `stdlib.h`, `string.h`, `helpers/helpers.h`, `idle_monitor/cpupower-monitor.h`.
- Detected declarations: `enum intel_snb_id`, `function snb_get_count`, `function snb_get_count_percent`, `function snb_start`, `function snb_stop`, `function snb_unregister`.
- Atlas domain: Support Tooling And Documentation / tools.
- Implementation status: source implementation candidate.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.