context_tracking: Split user tracking Kconfig
authorFrederic Weisbecker <frederic@kernel.org>
Wed, 8 Jun 2022 14:40:24 +0000 (16:40 +0200)
committerPaul E. McKenney <paulmck@kernel.org>
Thu, 30 Jun 2022 00:04:09 +0000 (17:04 -0700)
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>
25 files changed:
Documentation/features/time/context-tracking/arch-support.txt
arch/Kconfig
arch/arm/Kconfig
arch/arm/kernel/entry-common.S
arch/arm/kernel/entry-header.S
arch/arm64/Kconfig
arch/csky/Kconfig
arch/csky/kernel/entry.S
arch/loongarch/Kconfig
arch/mips/Kconfig
arch/powerpc/Kconfig
arch/powerpc/include/asm/context_tracking.h
arch/riscv/Kconfig
arch/riscv/kernel/entry.S
arch/sparc/Kconfig
arch/sparc/kernel/rtrap_64.S
arch/x86/Kconfig
arch/xtensa/Kconfig
arch/xtensa/kernel/entry.S
include/linux/context_tracking.h
include/linux/context_tracking_state.h
init/Kconfig
kernel/context_tracking.c
kernel/sched/core.c
kernel/time/Kconfig

index c9e0a16..e59071a 100644 (file)
@@ -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|
index fcf9a41..154b7b7 100644 (file)
@@ -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()
index 7630ba9..9acc6aa 100644 (file)
@@ -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
index 7aa3ded..37a0125 100644 (file)
@@ -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,
index 95def2b..99411fa 100644 (file)
@@ -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
index 1652a98..7c5dd2a 100644 (file)
@@ -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
index 21d72b0..f55ba17 100644 (file)
@@ -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
index bc734d1..547b4cd 100644 (file)
@@ -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:
index 1920d52..130dc65 100644 (file)
@@ -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
index db09d45..9457894 100644 (file)
@@ -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
index c2ce2e6..874c8d8 100644 (file)
@@ -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
index f2682b2..4b63931 100644 (file)
@@ -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
index 32ffef9..29b46f2 100644 (file)
@@ -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
index 12f6bba..b9eda3f 100644 (file)
@@ -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
 
index ba449c4..9232411 100644 (file)
@@ -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
index c5fd4b4..eef1027 100644 (file)
@@ -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
index be0b95e..b0a6dbb 100644 (file)
@@ -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
index 0b0f017..7927fed 100644 (file)
@@ -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
index d72bcaf..fb67d85 100644 (file)
@@ -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
index 63259fe..e35ae66 100644 (file)
@@ -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
index edc7b46..2b46afe 100644 (file)
@@ -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
index c7900e8..06454d1 100644 (file)
@@ -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
index d361bd5..f3dec1b 100644 (file)
@@ -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 */
index da0bf6f..883167a 100644 (file)
@@ -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)
 {
        /*
index 27b7868..41f99bc 100644 (file)
@@ -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.