context_tracking: Split user tracking Kconfig

Context tracking is going to be used not only to track user transitions
but also idle/IRQs/NMIs. The user tracking part will then become a
separate feature. Prepare Kconfig for that.

[ frederic: Apply Max Filippov feedback. ]

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
This commit is contained in:
Frederic Weisbecker 2022-06-08 16:40:24 +02:00 committed by Paul E. McKenney
parent 2a0aafce96
commit 24a9c54182
25 changed files with 65 additions and 52 deletions

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@ -1,7 +1,7 @@
#
# Feature name: context-tracking
# Kconfig: HAVE_CONTEXT_TRACKING
# description: arch supports context tracking for NO_HZ_FULL
# Feature name: user-context-tracking
# Kconfig: HAVE_CONTEXT_TRACKING_USER
# description: arch supports user context tracking for NO_HZ_FULL
#
-----------------------
| arch |status|

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@ -774,7 +774,7 @@ config HAVE_ARCH_WITHIN_STACK_FRAMES
and similar) by implementing an inline arch_within_stack_frames(),
which is used by CONFIG_HARDENED_USERCOPY.
config HAVE_CONTEXT_TRACKING
config HAVE_CONTEXT_TRACKING_USER
bool
help
Provide kernel/user boundaries probes necessary for subsystems
@ -785,7 +785,7 @@ config HAVE_CONTEXT_TRACKING
protected inside rcu_irq_enter/rcu_irq_exit() but preemption or signal
handling on irq exit still need to be protected.
config HAVE_CONTEXT_TRACKING_OFFSTACK
config HAVE_CONTEXT_TRACKING_USER_OFFSTACK
bool
help
Architecture neither relies on exception_enter()/exception_exit()

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@ -84,7 +84,7 @@ config ARM
select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARM_LPAE
select HAVE_ARM_SMCCC if CPU_V7
select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
select HAVE_CONTEXT_TRACKING
select HAVE_CONTEXT_TRACKING_USER
select HAVE_C_RECORDMCOUNT
select HAVE_BUILDTIME_MCOUNT_SORT
select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL

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@ -28,7 +28,7 @@
#include "entry-header.S"
saved_psr .req r8
#if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING)
#if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING_USER)
saved_pc .req r9
#define TRACE(x...) x
#else
@ -38,7 +38,7 @@ saved_pc .req lr
.section .entry.text,"ax",%progbits
.align 5
#if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING) || \
#if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING_USER) || \
IS_ENABLED(CONFIG_DEBUG_RSEQ))
/*
* This is the fast syscall return path. We do as little as possible here,

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@ -366,7 +366,7 @@ ALT_UP_B(.L1_\@)
* between user and kernel mode.
*/
.macro ct_user_exit, save = 1
#ifdef CONFIG_CONTEXT_TRACKING
#ifdef CONFIG_CONTEXT_TRACKING_USER
.if \save
stmdb sp!, {r0-r3, ip, lr}
bl user_exit_callable
@ -378,7 +378,7 @@ ALT_UP_B(.L1_\@)
.endm
.macro ct_user_enter, save = 1
#ifdef CONFIG_CONTEXT_TRACKING
#ifdef CONFIG_CONTEXT_TRACKING_USER
.if \save
stmdb sp!, {r0-r3, ip, lr}
bl user_enter_callable

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@ -174,7 +174,7 @@ config ARM64
select HAVE_C_RECORDMCOUNT
select HAVE_CMPXCHG_DOUBLE
select HAVE_CMPXCHG_LOCAL
select HAVE_CONTEXT_TRACKING
select HAVE_CONTEXT_TRACKING_USER
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS
select HAVE_DYNAMIC_FTRACE

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@ -42,7 +42,7 @@ config CSKY
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_MMAP_RND_BITS
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_CONTEXT_TRACKING
select HAVE_CONTEXT_TRACKING_USER
select HAVE_VIRT_CPU_ACCOUNTING_GEN
select HAVE_DEBUG_BUGVERBOSE
select HAVE_DEBUG_KMEMLEAK

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@ -19,7 +19,7 @@
.endm
.macro context_tracking
#ifdef CONFIG_CONTEXT_TRACKING
#ifdef CONFIG_CONTEXT_TRACKING_USER
mfcr a0, epsr
btsti a0, 31
bt 1f
@ -159,7 +159,7 @@ ret_from_exception:
and r10, r9
cmpnei r10, 0
bt exit_work
#ifdef CONFIG_CONTEXT_TRACKING
#ifdef CONFIG_CONTEXT_TRACKING_USER
jbsr user_enter_callable
#endif
1:

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@ -76,7 +76,7 @@ config LOONGARCH
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_TRANSPARENT_HUGEPAGE
select HAVE_ASM_MODVERSIONS
select HAVE_CONTEXT_TRACKING
select HAVE_CONTEXT_TRACKING_USER
select HAVE_COPY_THREAD_TLS
select HAVE_DEBUG_STACKOVERFLOW
select HAVE_DMA_CONTIGUOUS

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@ -56,7 +56,7 @@ config MIPS
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_TRANSPARENT_HUGEPAGE if CPU_SUPPORTS_HUGEPAGES
select HAVE_ASM_MODVERSIONS
select HAVE_CONTEXT_TRACKING
select HAVE_CONTEXT_TRACKING_USER
select HAVE_TIF_NOHZ
select HAVE_C_RECORDMCOUNT
select HAVE_DEBUG_KMEMLEAK

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@ -202,7 +202,7 @@ config PPC
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_TRACEHOOK
select HAVE_ASM_MODVERSIONS
select HAVE_CONTEXT_TRACKING if PPC64
select HAVE_CONTEXT_TRACKING_USER if PPC64
select HAVE_C_RECORDMCOUNT
select HAVE_DEBUG_KMEMLEAK
select HAVE_DEBUG_STACKOVERFLOW

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@ -2,7 +2,7 @@
#ifndef _ASM_POWERPC_CONTEXT_TRACKING_H
#define _ASM_POWERPC_CONTEXT_TRACKING_H
#ifdef CONFIG_CONTEXT_TRACKING
#ifdef CONFIG_CONTEXT_TRACKING_USER
#define SCHEDULE_USER bl schedule_user
#else
#define SCHEDULE_USER bl schedule

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@ -86,7 +86,7 @@ config RISCV
select HAVE_ARCH_THREAD_STRUCT_WHITELIST
select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
select HAVE_ASM_MODVERSIONS
select HAVE_CONTEXT_TRACKING
select HAVE_CONTEXT_TRACKING_USER
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS if MMU
select HAVE_EBPF_JIT if MMU

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@ -111,7 +111,7 @@ _save_context:
call __trace_hardirqs_off
#endif
#ifdef CONFIG_CONTEXT_TRACKING
#ifdef CONFIG_CONTEXT_TRACKING_USER
/* If previous state is in user mode, call user_exit_callable(). */
li a0, SR_PP
and a0, s1, a0
@ -176,7 +176,7 @@ handle_syscall:
*/
csrs CSR_STATUS, SR_IE
#endif
#if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING)
#if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING_USER)
/* Recover a0 - a7 for system calls */
REG_L a0, PT_A0(sp)
REG_L a1, PT_A1(sp)
@ -269,7 +269,7 @@ resume_userspace:
andi s1, s0, _TIF_WORK_MASK
bnez s1, work_pending
#ifdef CONFIG_CONTEXT_TRACKING
#ifdef CONFIG_CONTEXT_TRACKING_USER
call user_enter_callable
#endif

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@ -71,7 +71,7 @@ config SPARC64
select HAVE_DYNAMIC_FTRACE
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_CONTEXT_TRACKING
select HAVE_CONTEXT_TRACKING_USER
select HAVE_TIF_NOHZ
select HAVE_DEBUG_KMEMLEAK
select IOMMU_HELPER

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@ -15,7 +15,7 @@
#include <asm/visasm.h>
#include <asm/processor.h>
#ifdef CONFIG_CONTEXT_TRACKING
#ifdef CONFIG_CONTEXT_TRACKING_USER
# define SCHEDULE_USER schedule_user
#else
# define SCHEDULE_USER schedule

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@ -186,8 +186,8 @@ config X86
select HAVE_ASM_MODVERSIONS
select HAVE_CMPXCHG_DOUBLE
select HAVE_CMPXCHG_LOCAL
select HAVE_CONTEXT_TRACKING if X86_64
select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING
select HAVE_CONTEXT_TRACKING_USER if X86_64
select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER
select HAVE_C_RECORDMCOUNT
select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL
select HAVE_BUILDTIME_MCOUNT_SORT

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@ -33,7 +33,7 @@ config XTENSA
select HAVE_ARCH_KCSAN
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_TRACEHOOK
select HAVE_CONTEXT_TRACKING
select HAVE_CONTEXT_TRACKING_USER
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS
select HAVE_EXIT_THREAD

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@ -455,7 +455,7 @@ KABI_W or a3, a3, a2
abi_call trace_hardirqs_off
1:
#endif
#ifdef CONFIG_CONTEXT_TRACKING
#ifdef CONFIG_CONTEXT_TRACKING_USER
l32i abi_tmp0, a1, PT_PS
bbci.l abi_tmp0, PS_UM_BIT, 1f
abi_call user_exit_callable
@ -544,7 +544,7 @@ common_exception_return:
j .Lrestore_state
.Lexit_tif_loop_user:
#ifdef CONFIG_CONTEXT_TRACKING
#ifdef CONFIG_CONTEXT_TRACKING_USER
abi_call user_enter_callable
#endif
#ifdef CONFIG_HAVE_HW_BREAKPOINT

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@ -10,7 +10,7 @@
#include <asm/ptrace.h>
#ifdef CONFIG_CONTEXT_TRACKING
#ifdef CONFIG_CONTEXT_TRACKING_USER
extern void ct_cpu_track_user(int cpu);
/* Called with interrupts disabled. */
@ -52,7 +52,7 @@ static inline enum ctx_state exception_enter(void)
{
enum ctx_state prev_ctx;
if (IS_ENABLED(CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK) ||
if (IS_ENABLED(CONFIG_HAVE_CONTEXT_TRACKING_USER_OFFSTACK) ||
!context_tracking_enabled())
return 0;
@ -65,7 +65,7 @@ static inline enum ctx_state exception_enter(void)
static inline void exception_exit(enum ctx_state prev_ctx)
{
if (!IS_ENABLED(CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK) &&
if (!IS_ENABLED(CONFIG_HAVE_CONTEXT_TRACKING_USER_OFFSTACK) &&
context_tracking_enabled()) {
if (prev_ctx != CONTEXT_KERNEL)
ct_user_enter(prev_ctx);
@ -109,14 +109,14 @@ static inline enum ctx_state ct_state(void) { return CONTEXT_DISABLED; }
static __always_inline bool context_tracking_guest_enter(void) { return false; }
static inline void context_tracking_guest_exit(void) { }
#endif /* !CONFIG_CONTEXT_TRACKING */
#endif /* !CONFIG_CONTEXT_TRACKING_USER */
#define CT_WARN_ON(cond) WARN_ON(context_tracking_enabled() && (cond))
#ifdef CONFIG_CONTEXT_TRACKING_FORCE
#ifdef CONFIG_CONTEXT_TRACKING_USER_FORCE
extern void context_tracking_init(void);
#else
static inline void context_tracking_init(void) { }
#endif /* CONFIG_CONTEXT_TRACKING_FORCE */
#endif /* CONFIG_CONTEXT_TRACKING_USER_FORCE */
#endif

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@ -22,7 +22,7 @@ struct context_tracking {
} state;
};
#ifdef CONFIG_CONTEXT_TRACKING
#ifdef CONFIG_CONTEXT_TRACKING_USER
extern struct static_key_false context_tracking_key;
DECLARE_PER_CPU(struct context_tracking, context_tracking);
@ -45,6 +45,6 @@ static inline bool context_tracking_enabled_this_cpu(void)
static __always_inline bool context_tracking_enabled(void) { return false; }
static __always_inline bool context_tracking_enabled_cpu(int cpu) { return false; }
static __always_inline bool context_tracking_enabled_this_cpu(void) { return false; }
#endif /* CONFIG_CONTEXT_TRACKING */
#endif /* CONFIG_CONTEXT_TRACKING_USER */
#endif

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@ -494,11 +494,11 @@ config VIRT_CPU_ACCOUNTING_NATIVE
config VIRT_CPU_ACCOUNTING_GEN
bool "Full dynticks CPU time accounting"
depends on HAVE_CONTEXT_TRACKING
depends on HAVE_CONTEXT_TRACKING_USER
depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
depends on GENERIC_CLOCKEVENTS
select VIRT_CPU_ACCOUNTING
select CONTEXT_TRACKING
select CONTEXT_TRACKING_USER
help
Select this option to enable task and CPU time accounting on full
dynticks systems. This accounting is implemented by watching every

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@ -22,6 +22,8 @@
#include <linux/export.h>
#include <linux/kprobes.h>
#ifdef CONFIG_CONTEXT_TRACKING_USER
#define CREATE_TRACE_POINTS
#include <trace/events/context_tracking.h>
@ -252,7 +254,7 @@ void __init ct_cpu_track_user(int cpu)
initialized = true;
}
#ifdef CONFIG_CONTEXT_TRACKING_FORCE
#ifdef CONFIG_CONTEXT_TRACKING_USER_FORCE
void __init context_tracking_init(void)
{
int cpu;
@ -261,3 +263,5 @@ void __init context_tracking_init(void)
ct_cpu_track_user(cpu);
}
#endif
#endif /* #ifdef CONFIG_CONTEXT_TRACKING_USER */

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@ -6559,7 +6559,7 @@ void __sched schedule_idle(void)
} while (need_resched());
}
#if defined(CONFIG_CONTEXT_TRACKING) && !defined(CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK)
#if defined(CONFIG_CONTEXT_TRACKING_USER) && !defined(CONFIG_HAVE_CONTEXT_TRACKING_USER_OFFSTACK)
asmlinkage __visible void __sched schedule_user(void)
{
/*

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@ -73,6 +73,9 @@ config TIME_KUNIT_TEST
If unsure, say N.
config CONTEXT_TRACKING
bool
if GENERIC_CLOCKEVENTS
menu "Timers subsystem"
@ -111,7 +114,7 @@ config NO_HZ_FULL
# NO_HZ_COMMON dependency
# We need at least one periodic CPU for timekeeping
depends on SMP
depends on HAVE_CONTEXT_TRACKING
depends on HAVE_CONTEXT_TRACKING_USER
# VIRT_CPU_ACCOUNTING_GEN dependency
depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
select NO_HZ_COMMON
@ -137,31 +140,37 @@ config NO_HZ_FULL
endchoice
config CONTEXT_TRACKING
bool
config CONTEXT_TRACKING_USER
bool
depends on HAVE_CONTEXT_TRACKING_USER
select CONTEXT_TRACKING
help
Track transitions between kernel and user on behalf of RCU and
tickless cputime accounting. The former case relies on context
tracking to enter/exit RCU extended quiescent states.
config CONTEXT_TRACKING_FORCE
bool "Force context tracking"
depends on CONTEXT_TRACKING
config CONTEXT_TRACKING_USER_FORCE
bool "Force user context tracking"
depends on CONTEXT_TRACKING_USER
default y if !NO_HZ_FULL
help
The major pre-requirement for full dynticks to work is to
support the context tracking subsystem. But there are also
support the user context tracking subsystem. But there are also
other dependencies to provide in order to make the full
dynticks working.
This option stands for testing when an arch implements the
context tracking backend but doesn't yet fulfill all the
user context tracking backend but doesn't yet fulfill all the
requirements to make the full dynticks feature working.
Without the full dynticks, there is no way to test the support
for context tracking and the subsystems that rely on it: RCU
for user context tracking and the subsystems that rely on it: RCU
userspace extended quiescent state and tickless cputime
accounting. This option copes with the absence of the full
dynticks subsystem by forcing the context tracking on all
dynticks subsystem by forcing the user context tracking on all
CPUs in the system.
Say Y only if you're working on the development of an
architecture backend for the context tracking.
architecture backend for the user context tracking.
Say N otherwise, this option brings an overhead that you
don't want in production.