torvalds/linux
torvalds/linux
2
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-09-04 20:19:47 +08:00
Code

perf/core: Move perf_event sysctls into kernel/events

Browse Source 
Move ctl tables to two files:

 - perf_event_{paranoid,mlock_kb,max_sample_rate} and
   perf_cpu_time_max_percent into kernel/events/core.c

 - perf_event_max_{stack,context_per_stack} into
   kernel/events/callchain.c

Make static variables and functions that are fully contained in core.c
and callchain.cand remove them from include/linux/perf_event.h.
Additionally six_hundred_forty_kb is moved to callchain.c.

Two new sysctl tables are added ({callchain,events_core}_sysctl_table)
with their respective sysctl registration functions.

This is part of a greater effort to move ctl tables into their
respective subsystems which will reduce the merge conflicts in
kerenel/sysctl.c.

Signed-off-by: Joel Granados <joel.granados@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250218-jag-mv_ctltables-v1-5-cd3698ab8d29@kernel.org
This commit is contained in:
Joel Granados 2025-02-18 10:56:21 +01:00 committed by Ingo Molnar
parent e6e21a9a39
commit 8aeacf2570
4 changed files with 83 additions and 85 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
include/linux/perf_event.h
View File

@ -1652,19 +1652,10 @@ static inline int perf_callchain_store(struct perf_callchain_entry_ctx *ctx, u64
} }
extern int sysctl_perf_event_paranoid; extern int sysctl_perf_event_paranoid;
extern int sysctl_perf_event_mlock;
extern int sysctl_perf_event_sample_rate; extern int sysctl_perf_event_sample_rate;
extern int sysctl_perf_cpu_time_max_percent;
extern void perf_sample_event_took(u64 sample_len_ns); extern void perf_sample_event_took(u64 sample_len_ns);
int perf_event_max_sample_rate_handler(const struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos);
int perf_cpu_time_max_percent_handler(const struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos);
int perf_event_max_stack_handler(const struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos);
/* Access to perf_event_open(2) syscall. */ /* Access to perf_event_open(2) syscall. */
#define PERF_SECURITY_OPEN 0 #define PERF_SECURITY_OPEN 0

36
kernel/events/callchain.c
View File

@ -22,6 +22,7 @@ struct callchain_cpus_entries {
int sysctl_perf_event_max_stack __read_mostly = PERF_MAX_STACK_DEPTH; int sysctl_perf_event_max_stack __read_mostly = PERF_MAX_STACK_DEPTH;
int sysctl_perf_event_max_contexts_per_stack __read_mostly = PERF_MAX_CONTEXTS_PER_STACK; int sysctl_perf_event_max_contexts_per_stack __read_mostly = PERF_MAX_CONTEXTS_PER_STACK;
static const int six_hundred_forty_kb = 640 * 1024;
static inline size_t perf_callchain_entry__sizeof(void) static inline size_t perf_callchain_entry__sizeof(void)
{ {
@ -266,11 +267,7 @@ exit_put:
return entry; return entry;
} }
/* static int perf_event_max_stack_handler(const struct ctl_table *table, int write,
* Used for sysctl_perf_event_max_stack and
* sysctl_perf_event_max_contexts_per_stack.
*/
int perf_event_max_stack_handler(const struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos) void *buffer, size_t *lenp, loff_t *ppos)
{ {
int *value = table->data; int *value = table->data;
@ -292,3 +289,32 @@ int perf_event_max_stack_handler(const struct ctl_table *table, int write,
return ret; return ret;
} }
static const struct ctl_table callchain_sysctl_table[] = {
{
.procname = "perf_event_max_stack",
.data = &sysctl_perf_event_max_stack,
.maxlen = sizeof(sysctl_perf_event_max_stack),
.mode = 0644,
.proc_handler = perf_event_max_stack_handler,
.extra1 = SYSCTL_ZERO,
.extra2 = (void *)&six_hundred_forty_kb,
},
{
.procname = "perf_event_max_contexts_per_stack",
.data = &sysctl_perf_event_max_contexts_per_stack,
.maxlen = sizeof(sysctl_perf_event_max_contexts_per_stack),
.mode = 0644,
.proc_handler = perf_event_max_stack_handler,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE_THOUSAND,
},
};
static int __init init_callchain_sysctls(void)
{
register_sysctl_init("kernel", callchain_sysctl_table);
return 0;
}
core_initcall(init_callchain_sysctls);

57
kernel/events/core.c
View File

@ -452,8 +452,8 @@ static struct kmem_cache *perf_event_cache;
*/ */
int sysctl_perf_event_paranoid __read_mostly = 2; int sysctl_perf_event_paranoid __read_mostly = 2;
/* Minimum for 512 kiB + 1 user control page */ /* Minimum for 512 kiB + 1 user control page. 'free' kiB per user. */
int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ static int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024);
/* /*
* max perf event sample rate * max perf event sample rate
@ -463,6 +463,7 @@ int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free'
#define DEFAULT_CPU_TIME_MAX_PERCENT 25 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE; int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE;
static int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT;
static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ); static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ);
static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS; static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS;
@ -484,7 +485,7 @@ static void update_perf_cpu_limits(void)
static bool perf_rotate_context(struct perf_cpu_pmu_context *cpc); static bool perf_rotate_context(struct perf_cpu_pmu_context *cpc);
int perf_event_max_sample_rate_handler(const struct ctl_table *table, int write, static int perf_event_max_sample_rate_handler(const struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos) void *buffer, size_t *lenp, loff_t *ppos)
{ {
int ret; int ret;
@ -506,9 +507,7 @@ int perf_event_max_sample_rate_handler(const struct ctl_table *table, int write,
return 0; return 0;
} }
int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT; static int perf_cpu_time_max_percent_handler(const struct ctl_table *table, int write,
int perf_cpu_time_max_percent_handler(const struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos) void *buffer, size_t *lenp, loff_t *ppos)
{ {
int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
@ -528,6 +527,52 @@ int perf_cpu_time_max_percent_handler(const struct ctl_table *table, int write,
return 0; return 0;
} }
static const struct ctl_table events_core_sysctl_table[] = {
/*
* User-space relies on this file as a feature check for
* perf_events being enabled. It's an ABI, do not remove!
*/
{
.procname = "perf_event_paranoid",
.data = &sysctl_perf_event_paranoid,
.maxlen = sizeof(sysctl_perf_event_paranoid),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "perf_event_mlock_kb",
.data = &sysctl_perf_event_mlock,
.maxlen = sizeof(sysctl_perf_event_mlock),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "perf_event_max_sample_rate",
.data = &sysctl_perf_event_sample_rate,
.maxlen = sizeof(sysctl_perf_event_sample_rate),
.mode = 0644,
.proc_handler = perf_event_max_sample_rate_handler,
.extra1 = SYSCTL_ONE,
},
{
.procname = "perf_cpu_time_max_percent",
.data = &sysctl_perf_cpu_time_max_percent,
.maxlen = sizeof(sysctl_perf_cpu_time_max_percent),
.mode = 0644,
.proc_handler = perf_cpu_time_max_percent_handler,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE_HUNDRED,
},
};
static int __init init_events_core_sysctls(void)
{
register_sysctl_init("kernel", events_core_sysctl_table);
return 0;
}
core_initcall(init_events_core_sysctls);
/* /*
* perf samples are done in some very critical code paths (NMIs). * perf samples are done in some very critical code paths (NMIs).
* If they take too much CPU time, the system can lock up and not * If they take too much CPU time, the system can lock up and not

64
kernel/sysctl.c
View File

@ -54,7 +54,6 @@
#include <linux/acpi.h> #include <linux/acpi.h>
#include <linux/reboot.h> #include <linux/reboot.h>
#include <linux/ftrace.h> #include <linux/ftrace.h>
#include <linux/perf_event.h>
#include <linux/oom.h> #include <linux/oom.h>
#include <linux/kmod.h> #include <linux/kmod.h>
#include <linux/capability.h> #include <linux/capability.h>
@ -91,12 +90,6 @@ EXPORT_SYMBOL_GPL(sysctl_long_vals);
#if defined(CONFIG_SYSCTL) #if defined(CONFIG_SYSCTL)
/* Constants used for minimum and maximum */ /* Constants used for minimum and maximum */
#ifdef CONFIG_PERF_EVENTS
static const int six_hundred_forty_kb = 640 * 1024;
#endif
static const int ngroups_max = NGROUPS_MAX; static const int ngroups_max = NGROUPS_MAX;
static const int cap_last_cap = CAP_LAST_CAP; static const int cap_last_cap = CAP_LAST_CAP;
@ -1932,63 +1925,6 @@ static const struct ctl_table kern_table[] = {
.mode = 0644, .mode = 0644,
.proc_handler = proc_dointvec, .proc_handler = proc_dointvec,
}, },
#endif
#ifdef CONFIG_PERF_EVENTS
/*
* User-space scripts rely on the existence of this file
* as a feature check for perf_events being enabled.
*
* So it's an ABI, do not remove!
*/
{
.procname = "perf_event_paranoid",
.data = &sysctl_perf_event_paranoid,
.maxlen = sizeof(sysctl_perf_event_paranoid),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "perf_event_mlock_kb",
.data = &sysctl_perf_event_mlock,
.maxlen = sizeof(sysctl_perf_event_mlock),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "perf_event_max_sample_rate",
.data = &sysctl_perf_event_sample_rate,
.maxlen = sizeof(sysctl_perf_event_sample_rate),
.mode = 0644,
.proc_handler = perf_event_max_sample_rate_handler,
.extra1 = SYSCTL_ONE,
},
{
.procname = "perf_cpu_time_max_percent",
.data = &sysctl_perf_cpu_time_max_percent,
.maxlen = sizeof(sysctl_perf_cpu_time_max_percent),
.mode = 0644,
.proc_handler = perf_cpu_time_max_percent_handler,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE_HUNDRED,
},
{
.procname = "perf_event_max_stack",
.data = &sysctl_perf_event_max_stack,
.maxlen = sizeof(sysctl_perf_event_max_stack),
.mode = 0644,
.proc_handler = perf_event_max_stack_handler,
.extra1 = SYSCTL_ZERO,
.extra2 = (void *)&six_hundred_forty_kb,
},
{
.procname = "perf_event_max_contexts_per_stack",
.data = &sysctl_perf_event_max_contexts_per_stack,
.maxlen = sizeof(sysctl_perf_event_max_contexts_per_stack),
.mode = 0644,
.proc_handler = perf_event_max_stack_handler,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE_THOUSAND,
},
#endif #endif
{ {
.procname = "panic_on_warn", .procname = "panic_on_warn",