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Subject[PATCH] static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]()

[ Resent with a [PATCH] prefix added to the subject line.
Sorry about the duplicate. ]

* Ingo Molnar <mingo@elte.hu> wrote:

> * Ingo Molnar <mingo@elte.hu> wrote:
>
> > So, a modified scheme would be:
> >
> > #include <linux/static_key.h>
> >
> > struct static_key key = STATIC_KEY_INIT_TRUE;
> >
> > if (static_key_false(&key))
> > do unlikely code
> > else
> > do likely code
> >
> > Or:
> >
> > if (static_key_true(&key))
> > do likely code
> > else
> > do unlikely code
> >
> > The static key is modified via:
> >
> > static_key_slow_inc(&key);
> > ...
> > static_key_slow_dec(&key);
> >
> > Is that API fine? I'll rework the series to such an effect if
> > everyone agrees.
>
> I.e. something like the patch below on top of
> tip:perf/jump-labels.
>
> Untested - will test it and will refactor the series if
> everyone's happy.

So, below is the second version of my 'struct static_key' patch,
with the confusing very_likely()/very_unlikely() method renamed
to static_key_true()/static_key_false().

Thanks,

Ingo

-------------------->
From 25764dffac2414774b65a831733b232d33006884 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 24 Feb 2012 08:31:31 +0100
Subject: [PATCH] static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]()
So here's a boot tested patch on top of Jason's series that does
all the cleanups I talked about and turns jump labels into a
more intuitive to use facility. It should also address the
various misconceptions and confusions that surround jump labels.

Typical usage scenarios:

#include <linux/static_key.h>

struct static_key key = STATIC_KEY_INIT_TRUE;

if (static_key_false(&key))
do unlikely code
else
do likely code
Or:

if (static_key_true(&key))
do likely code
else
do unlikely code
The static key is modified via:

static_key_slow_inc(&key);
...
static_key_slow_dec(&key);

The 'slow' prefix makes it abundantly clear that this is an
expensive operation.

I've updated all in-kernel code to use this everywhere. Note
that I (intentionally) have not pushed through the rename
blindly through to the lowest levels: the actual jump-label
patching arch facility should be named like that, so we want to
decouple jump labels from the static-key facility a bit.

On non-jump-label enabled architectures static keys default to
likely()/unlikely() branches.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: a.p.zijlstra@chello.nl
Cc: mathieu.desnoyers@efficios.com
Cc: davem@davemloft.net
Cc: ddaney.cavm@gmail.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20120222085809.GA26397@elte.hu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/Kconfig | 29 +++++--
arch/ia64/include/asm/paravirt.h | 6 +-
arch/ia64/kernel/paravirt.c | 4 +-
arch/mips/include/asm/jump_label.h | 2 +-
arch/powerpc/include/asm/jump_label.h | 2 +-
arch/s390/include/asm/jump_label.h | 2 +-
arch/sparc/include/asm/jump_label.h | 2 +-
arch/x86/include/asm/jump_label.h | 6 +-
arch/x86/include/asm/paravirt.h | 6 +-
arch/x86/kernel/kvm.c | 4 +-
arch/x86/kernel/paravirt.c | 4 +-
arch/x86/kvm/mmu_audit.c | 8 +-
include/linux/jump_label.h | 139 +++++++++++++++++++++++---------
include/linux/netdevice.h | 4 +-
include/linux/netfilter.h | 6 +-
include/linux/perf_event.h | 12 ++--
include/linux/static_key.h | 1 +
include/linux/tracepoint.h | 8 +-
include/net/sock.h | 6 +-
kernel/events/core.c | 16 ++--
kernel/jump_label.c | 128 +++++++++++++++++-------------
kernel/sched/core.c | 18 ++--
kernel/sched/fair.c | 8 +-
kernel/sched/sched.h | 14 ++--
kernel/tracepoint.c | 20 +++---
net/core/dev.c | 24 +++---
net/core/net-sysfs.c | 4 +-
net/core/sock.c | 4 +-
net/core/sysctl_net_core.c | 4 +-
net/ipv4/tcp_memcontrol.c | 6 +-
net/netfilter/core.c | 6 +-
31 files changed, 298 insertions(+), 205 deletions(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index 4f55c73..5b448a7 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -47,18 +47,29 @@ config KPROBES
If in doubt, say "N".

config JUMP_LABEL
- bool "Optimize trace point call sites"
+ bool "Optimize very unlikely/likely branches"
depends on HAVE_ARCH_JUMP_LABEL
help
+ This option enables a transparent branch optimization that
+ makes certain almost-always-true or almost-always-false branch
+ conditions even cheaper to execute within the kernel.
+
+ Certain performance-sensitive kernel code, such as trace points,
+ scheduler functionality, networking code and KVM have such
+ branches and include support for this optimization technique.
+
If it is detected that the compiler has support for "asm goto",
- the kernel will compile trace point locations with just a
- nop instruction. When trace points are enabled, the nop will
- be converted to a jump to the trace function. This technique
- lowers overhead and stress on the branch prediction of the
- processor.
-
- On i386, options added to the compiler flags may increase
- the size of the kernel slightly.
+ the kernel will compile such branches with just a nop
+ instruction. When the condition flag is toggled to true, the
+ nop will be converted to a jump instruction to execute the
+ conditional block of instructions.
+
+ This technique lowers overhead and stress on the branch prediction
+ of the processor and generally makes the kernel faster. The update
+ of the condition is slower, but those are always very rare.
+
+ ( On 32-bit x86, the necessary options added to the compiler
+ flags may increase the size of the kernel slightly. )

config OPTPROBES
def_bool y
diff --git a/arch/ia64/include/asm/paravirt.h b/arch/ia64/include/asm/paravirt.h
index 32551d3..b149b88 100644
--- a/arch/ia64/include/asm/paravirt.h
+++ b/arch/ia64/include/asm/paravirt.h
@@ -281,9 +281,9 @@ paravirt_init_missing_ticks_accounting(int cpu)
pv_time_ops.init_missing_ticks_accounting(cpu);
}

-struct jump_label_key;
-extern struct jump_label_key paravirt_steal_enabled;
-extern struct jump_label_key paravirt_steal_rq_enabled;
+struct static_key;
+extern struct static_key paravirt_steal_enabled;
+extern struct static_key paravirt_steal_rq_enabled;

static inline int
paravirt_do_steal_accounting(unsigned long *new_itm)
diff --git a/arch/ia64/kernel/paravirt.c b/arch/ia64/kernel/paravirt.c
index 1008682..1b22f6d 100644
--- a/arch/ia64/kernel/paravirt.c
+++ b/arch/ia64/kernel/paravirt.c
@@ -634,8 +634,8 @@ struct pv_irq_ops pv_irq_ops = {
* pv_time_ops
* time operations
*/
-struct jump_label_key paravirt_steal_enabled;
-struct jump_label_key paravirt_steal_rq_enabled;
+struct static_key paravirt_steal_enabled;
+struct static_key paravirt_steal_rq_enabled;

static int
ia64_native_do_steal_accounting(unsigned long *new_itm)
diff --git a/arch/mips/include/asm/jump_label.h b/arch/mips/include/asm/jump_label.h
index 1881b31..4d6d77e 100644
--- a/arch/mips/include/asm/jump_label.h
+++ b/arch/mips/include/asm/jump_label.h
@@ -20,7 +20,7 @@
#define WORD_INSN ".word"
#endif

-static __always_inline bool arch_static_branch(struct jump_label_key *key)
+static __always_inline bool arch_static_branch(struct static_key *key)
{
asm goto("1:\tnop\n\t"
"nop\n\t"
diff --git a/arch/powerpc/include/asm/jump_label.h b/arch/powerpc/include/asm/jump_label.h
index 938986e..ae098c4 100644
--- a/arch/powerpc/include/asm/jump_label.h
+++ b/arch/powerpc/include/asm/jump_label.h
@@ -17,7 +17,7 @@
#define JUMP_ENTRY_TYPE stringify_in_c(FTR_ENTRY_LONG)
#define JUMP_LABEL_NOP_SIZE 4

-static __always_inline bool arch_static_branch(struct jump_label_key *key)
+static __always_inline bool arch_static_branch(struct static_key *key)
{
asm goto("1:\n\t"
"nop\n\t"
diff --git a/arch/s390/include/asm/jump_label.h b/arch/s390/include/asm/jump_label.h
index 95a6cf2..6c32190 100644
--- a/arch/s390/include/asm/jump_label.h
+++ b/arch/s390/include/asm/jump_label.h
@@ -13,7 +13,7 @@
#define ASM_ALIGN ".balign 4"
#endif

-static __always_inline bool arch_static_branch(struct jump_label_key *key)
+static __always_inline bool arch_static_branch(struct static_key *key)
{
asm goto("0: brcl 0,0\n"
".pushsection __jump_table, \"aw\"\n"
diff --git a/arch/sparc/include/asm/jump_label.h b/arch/sparc/include/asm/jump_label.h
index fc73a82..5080d16 100644
--- a/arch/sparc/include/asm/jump_label.h
+++ b/arch/sparc/include/asm/jump_label.h
@@ -7,7 +7,7 @@

#define JUMP_LABEL_NOP_SIZE 4

-static __always_inline bool arch_static_branch(struct jump_label_key *key)
+static __always_inline bool arch_static_branch(struct static_key *key)
{
asm goto("1:\n\t"
"nop\n\t"
diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h
index a32b18c..3a16c14 100644
--- a/arch/x86/include/asm/jump_label.h
+++ b/arch/x86/include/asm/jump_label.h
@@ -9,12 +9,12 @@

#define JUMP_LABEL_NOP_SIZE 5

-#define JUMP_LABEL_INITIAL_NOP ".byte 0xe9 \n\t .long 0\n\t"
+#define STATIC_KEY_INITIAL_NOP ".byte 0xe9 \n\t .long 0\n\t"

-static __always_inline bool arch_static_branch(struct jump_label_key *key)
+static __always_inline bool arch_static_branch(struct static_key *key)
{
asm goto("1:"
- JUMP_LABEL_INITIAL_NOP
+ STATIC_KEY_INITIAL_NOP
".pushsection __jump_table, \"aw\" \n\t"
_ASM_ALIGN "\n\t"
_ASM_PTR "1b, %l[l_yes], %c0 \n\t"
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index a7d2db9..c0180fd 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -230,9 +230,9 @@ static inline unsigned long long paravirt_sched_clock(void)
return PVOP_CALL0(unsigned long long, pv_time_ops.sched_clock);
}

-struct jump_label_key;
-extern struct jump_label_key paravirt_steal_enabled;
-extern struct jump_label_key paravirt_steal_rq_enabled;
+struct static_key;
+extern struct static_key paravirt_steal_enabled;
+extern struct static_key paravirt_steal_rq_enabled;

static inline u64 paravirt_steal_clock(int cpu)
{
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index f0c6fd6..694d801 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -438,9 +438,9 @@ void __init kvm_guest_init(void)
static __init int activate_jump_labels(void)
{
if (has_steal_clock) {
- jump_label_inc(&paravirt_steal_enabled);
+ static_key_slow_inc(&paravirt_steal_enabled);
if (steal_acc)
- jump_label_inc(&paravirt_steal_rq_enabled);
+ static_key_slow_inc(&paravirt_steal_rq_enabled);
}

return 0;
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index d90272e..ada2f99 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -202,8 +202,8 @@ static void native_flush_tlb_single(unsigned long addr)
__native_flush_tlb_single(addr);
}

-struct jump_label_key paravirt_steal_enabled;
-struct jump_label_key paravirt_steal_rq_enabled;
+struct static_key paravirt_steal_enabled;
+struct static_key paravirt_steal_rq_enabled;

static u64 native_steal_clock(int cpu)
{
diff --git a/arch/x86/kvm/mmu_audit.c b/arch/x86/kvm/mmu_audit.c
index fe15dcc..ea7b4fd 100644
--- a/arch/x86/kvm/mmu_audit.c
+++ b/arch/x86/kvm/mmu_audit.c
@@ -234,7 +234,7 @@ static void audit_vcpu_spte(struct kvm_vcpu *vcpu)
}

static bool mmu_audit;
-static struct jump_label_key mmu_audit_key;
+static struct static_key mmu_audit_key;

static void __kvm_mmu_audit(struct kvm_vcpu *vcpu, int point)
{
@@ -250,7 +250,7 @@ static void __kvm_mmu_audit(struct kvm_vcpu *vcpu, int point)

static inline void kvm_mmu_audit(struct kvm_vcpu *vcpu, int point)
{
- if (static_branch((&mmu_audit_key)))
+ if (static_key_false((&mmu_audit_key)))
__kvm_mmu_audit(vcpu, point);
}

@@ -259,7 +259,7 @@ static void mmu_audit_enable(void)
if (mmu_audit)
return;

- jump_label_inc(&mmu_audit_key);
+ static_key_slow_inc(&mmu_audit_key);
mmu_audit = true;
}

@@ -268,7 +268,7 @@ static void mmu_audit_disable(void)
if (!mmu_audit)
return;

- jump_label_dec(&mmu_audit_key);
+ static_key_slow_dec(&mmu_audit_key);
mmu_audit = false;
}

diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index f7c6958..30d0023 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -9,15 +9,15 @@
*
* Jump labels provide an interface to generate dynamic branches using
* self-modifying code. Assuming toolchain and architecture support the result
- * of a "if (static_branch(&key))" statement is a unconditional branch (which
+ * of a "if (static_key_false(&key))" statement is a unconditional branch (which
* defaults to false - and the true block is placed out of line).
*
- * However at runtime we can change the 'static' branch target using
- * jump_label_{inc,dec}(). These function as a 'reference' count on the key
+ * However at runtime we can change the branch target using
+ * static_key_slow_{inc,dec}(). These function as a 'reference' count on the key
* object and for as long as there are references all branches referring to
* that particular key will point to the (out of line) true block.
*
- * Since this relies on modifying code the jump_label_{inc,dec}() functions
+ * Since this relies on modifying code the static_key_slow_{inc,dec}() functions
* must be considered absolute slow paths (machine wide synchronization etc.).
* OTOH, since the affected branches are unconditional their runtime overhead
* will be absolutely minimal, esp. in the default (off) case where the total
@@ -26,12 +26,26 @@
*
* When the control is directly exposed to userspace it is prudent to delay the
* decrement to avoid high frequency code modifications which can (and do)
- * cause significant performance degradation. Struct jump_label_key_deferred and
- * jump_label_dec_deferred() provide for this.
+ * cause significant performance degradation. Struct static_key_deferred and
+ * static_key_slow_dec_deferred() provide for this.
*
* Lacking toolchain and or architecture support, it falls back to a simple
* conditional branch.
- */
+ *
+ * struct static_key my_key = STATIC_KEY_INIT_TRUE;
+ *
+ * if (static_key_true(&my_key)) {
+ * }
+ *
+ * will result in the true case being in-line and starts the key with a single
+ * reference. Mixing static_key_true() and static_key_false() on the same key is not
+ * allowed.
+ *
+ * Not initializing the key (static data is initialized to 0s anyway) is the
+ * same as using STATIC_KEY_INIT_FALSE and static_key_false() is
+ * equivalent with static_branch().
+ *
+*/

#include <linux/types.h>
#include <linux/compiler.h>
@@ -39,16 +53,17 @@

#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)

-struct jump_label_key {
+struct static_key {
atomic_t enabled;
+/* Set lsb bit to 1 if branch is default true, 0 ot */
struct jump_entry *entries;
#ifdef CONFIG_MODULES
- struct jump_label_mod *next;
+ struct static_key_mod *next;
#endif
};

-struct jump_label_key_deferred {
- struct jump_label_key key;
+struct static_key_deferred {
+ struct static_key key;
unsigned long timeout;
struct delayed_work work;
};
@@ -66,13 +81,34 @@ struct module;

#ifdef HAVE_JUMP_LABEL

-#ifdef CONFIG_MODULES
-#define JUMP_LABEL_INIT {ATOMIC_INIT(0), NULL, NULL}
-#else
-#define JUMP_LABEL_INIT {ATOMIC_INIT(0), NULL}
-#endif
+#define JUMP_LABEL_TRUE_BRANCH 1UL
+
+static
+inline struct jump_entry *jump_label_get_entries(struct static_key *key)
+{
+ return (struct jump_entry *)((unsigned long)key->entries
+ & ~JUMP_LABEL_TRUE_BRANCH);
+}
+
+static inline bool jump_label_get_branch_default(struct static_key *key)
+{
+ if ((unsigned long)key->entries & JUMP_LABEL_TRUE_BRANCH)
+ return true;
+ return false;
+}
+
+static __always_inline bool static_key_false(struct static_key *key)
+{
+ return arch_static_branch(key);
+}

-static __always_inline bool static_branch(struct jump_label_key *key)
+static __always_inline bool static_key_true(struct static_key *key)
+{
+ return !static_key_false(key);
+}
+
+/* Deprecated. Please use 'static_key_false() instead. */
+static __always_inline bool static_branch(struct static_key *key)
{
return arch_static_branch(key);
}
@@ -88,21 +124,24 @@ extern void arch_jump_label_transform(struct jump_entry *entry,
extern void arch_jump_label_transform_static(struct jump_entry *entry,
enum jump_label_type type);
extern int jump_label_text_reserved(void *start, void *end);
-extern void jump_label_inc(struct jump_label_key *key);
-extern void jump_label_dec(struct jump_label_key *key);
-extern void jump_label_dec_deferred(struct jump_label_key_deferred *key);
-extern bool jump_label_enabled(struct jump_label_key *key);
+extern void static_key_slow_inc(struct static_key *key);
+extern void static_key_slow_dec(struct static_key *key);
+extern void static_key_slow_dec_deferred(struct static_key_deferred *key);
+extern bool static_key_true(struct static_key *key);
extern void jump_label_apply_nops(struct module *mod);
-extern void jump_label_rate_limit(struct jump_label_key_deferred *key,
- unsigned long rl);
+extern void
+jump_label_rate_limit(struct static_key_deferred *key, unsigned long rl);
+
+#define STATIC_KEY_INIT_TRUE ((struct static_key) \
+ { .enabled = ATOMIC_INIT(1), .entries = (void *)1 })
+#define STATIC_KEY_INIT_FALSE ((struct static_key) \
+ { .enabled = ATOMIC_INIT(0), .entries = (void *)0 })

#else /* !HAVE_JUMP_LABEL */

#include <linux/atomic.h>

-#define JUMP_LABEL_INIT {ATOMIC_INIT(0)}
-
-struct jump_label_key {
+struct static_key {
atomic_t enabled;
};

@@ -110,30 +149,45 @@ static __always_inline void jump_label_init(void)
{
}

-struct jump_label_key_deferred {
- struct jump_label_key key;
+struct static_key_deferred {
+ struct static_key key;
};

-static __always_inline bool static_branch(struct jump_label_key *key)
+static __always_inline bool static_key_false(struct static_key *key)
+{
+ if (unlikely(atomic_read(&key->enabled)) > 0)
+ return true;
+ return false;
+}
+
+static __always_inline bool static_key_true(struct static_key *key)
{
- if (unlikely(atomic_read(&key->enabled)))
+ if (likely(atomic_read(&key->enabled)) > 0)
return true;
return false;
}

-static inline void jump_label_inc(struct jump_label_key *key)
+/* Deprecated. Please use 'static_key_false() instead. */
+static __always_inline bool static_branch(struct static_key *key)
+{
+ if (unlikely(atomic_read(&key->enabled)) > 0)
+ return true;
+ return false;
+}
+
+static inline void static_key_slow_inc(struct static_key *key)
{
atomic_inc(&key->enabled);
}

-static inline void jump_label_dec(struct jump_label_key *key)
+static inline void static_key_slow_dec(struct static_key *key)
{
atomic_dec(&key->enabled);
}

-static inline void jump_label_dec_deferred(struct jump_label_key_deferred *key)
+static inline void static_key_slow_dec_deferred(struct static_key_deferred *key)
{
- jump_label_dec(&key->key);
+ static_key_slow_dec(&key->key);
}

static inline int jump_label_text_reserved(void *start, void *end)
@@ -144,9 +198,9 @@ static inline int jump_label_text_reserved(void *start, void *end)
static inline void jump_label_lock(void) {}
static inline void jump_label_unlock(void) {}

-static inline bool jump_label_enabled(struct jump_label_key *key)
+static inline bool static_key_true(struct static_key *key)
{
- return !!atomic_read(&key->enabled);
+ return (atomic_read(&key->enabled) > 0);
}

static inline int jump_label_apply_nops(struct module *mod)
@@ -154,13 +208,20 @@ static inline int jump_label_apply_nops(struct module *mod)
return 0;
}

-static inline void jump_label_rate_limit(struct jump_label_key_deferred *key,
+static inline void
+jump_label_rate_limit(struct static_key_deferred *key,
unsigned long rl)
{
}
+
+#define STATIC_KEY_INIT_TRUE ((struct static_key) \
+ { .enabled = ATOMIC_INIT(1) })
+#define STATIC_KEY_INIT_FALSE ((struct static_key) \
+ { .enabled = ATOMIC_INIT(0) })
+
#endif /* HAVE_JUMP_LABEL */

-#define jump_label_key_enabled ((struct jump_label_key){ .enabled = ATOMIC_INIT(1), })
-#define jump_label_key_disabled ((struct jump_label_key){ .enabled = ATOMIC_INIT(0), })
+#define STATIC_KEY_INIT STATIC_KEY_INIT_FALSE
+#define jump_label_enabled static_key_true

#endif /* _LINUX_JUMP_LABEL_H */
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 0eac07c..7dfaae7 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -214,8 +214,8 @@ enum {
#include <linux/skbuff.h>

#ifdef CONFIG_RPS
-#include <linux/jump_label.h>
-extern struct jump_label_key rps_needed;
+#include <linux/static_key.h>
+extern struct static_key rps_needed;
#endif

struct neighbour;
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index b809265..29734be 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -163,13 +163,13 @@ extern struct ctl_path nf_net_ipv4_netfilter_sysctl_path[];
extern struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS];

#if defined(CONFIG_JUMP_LABEL)
-#include <linux/jump_label.h>
-extern struct jump_label_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
+#include <linux/static_key.h>
+extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook)
{
if (__builtin_constant_p(pf) &&
__builtin_constant_p(hook))
- return static_branch(&nf_hooks_needed[pf][hook]);
+ return static_key_false(&nf_hooks_needed[pf][hook]);

return !list_empty(&nf_hooks[pf][hook]);
}
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 412b790..0d21e6f 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -514,7 +514,7 @@ struct perf_guest_info_callbacks {
#include <linux/ftrace.h>
#include <linux/cpu.h>
#include <linux/irq_work.h>
-#include <linux/jump_label.h>
+#include <linux/static_key.h>
#include <linux/atomic.h>
#include <asm/local.h>

@@ -1038,7 +1038,7 @@ static inline int is_software_event(struct perf_event *event)
return event->pmu->task_ctx_nr == perf_sw_context;
}

-extern struct jump_label_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
+extern struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];

extern void __perf_sw_event(u32, u64, struct pt_regs *, u64);

@@ -1066,7 +1066,7 @@ perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
{
struct pt_regs hot_regs;

- if (static_branch(&perf_swevent_enabled[event_id])) {
+ if (static_key_false(&perf_swevent_enabled[event_id])) {
if (!regs) {
perf_fetch_caller_regs(&hot_regs);
regs = &hot_regs;
@@ -1075,12 +1075,12 @@ perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
}
}

-extern struct jump_label_key_deferred perf_sched_events;
+extern struct static_key_deferred perf_sched_events;

static inline void perf_event_task_sched_in(struct task_struct *prev,
struct task_struct *task)
{
- if (static_branch(&perf_sched_events.key))
+ if (static_key_false(&perf_sched_events.key))
__perf_event_task_sched_in(prev, task);
}

@@ -1089,7 +1089,7 @@ static inline void perf_event_task_sched_out(struct task_struct *prev,
{
perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, NULL, 0);

- if (static_branch(&perf_sched_events.key))
+ if (static_key_false(&perf_sched_events.key))
__perf_event_task_sched_out(prev, next);
}

diff --git a/include/linux/static_key.h b/include/linux/static_key.h
new file mode 100644
index 0000000..27bd3f8
--- /dev/null
+++ b/include/linux/static_key.h
@@ -0,0 +1 @@
+#include <linux/jump_label.h>
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index fc36da9..bd96ecd 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -17,7 +17,7 @@
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/rcupdate.h>
-#include <linux/jump_label.h>
+#include <linux/static_key.h>

struct module;
struct tracepoint;
@@ -29,7 +29,7 @@ struct tracepoint_func {

struct tracepoint {
const char *name; /* Tracepoint name */
- struct jump_label_key key;
+ struct static_key key;
void (*regfunc)(void);
void (*unregfunc)(void);
struct tracepoint_func __rcu *funcs;
@@ -145,7 +145,7 @@ static inline void tracepoint_synchronize_unregister(void)
extern struct tracepoint __tracepoint_##name; \
static inline void trace_##name(proto) \
{ \
- if (static_branch(&__tracepoint_##name.key)) \
+ if (static_key_false(&__tracepoint_##name.key)) \
__DO_TRACE(&__tracepoint_##name, \
TP_PROTO(data_proto), \
TP_ARGS(data_args), \
@@ -188,7 +188,7 @@ static inline void tracepoint_synchronize_unregister(void)
__attribute__((section("__tracepoints_strings"))) = #name; \
struct tracepoint __tracepoint_##name \
__attribute__((section("__tracepoints"))) = \
- { __tpstrtab_##name, JUMP_LABEL_INIT, reg, unreg, NULL };\
+ { __tpstrtab_##name, STATIC_KEY_INIT_FALSE, reg, unreg, NULL };\
static struct tracepoint * const __tracepoint_ptr_##name __used \
__attribute__((section("__tracepoints_ptrs"))) = \
&__tracepoint_##name;
diff --git a/include/net/sock.h b/include/net/sock.h
index 91c1c8b..dcde2d9 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -55,7 +55,7 @@
#include <linux/uaccess.h>
#include <linux/memcontrol.h>
#include <linux/res_counter.h>
-#include <linux/jump_label.h>
+#include <linux/static_key.h>

#include <linux/filter.h>
#include <linux/rculist_nulls.h>
@@ -924,13 +924,13 @@ inline void sk_refcnt_debug_release(const struct sock *sk)
#endif /* SOCK_REFCNT_DEBUG */

#if defined(CONFIG_CGROUP_MEM_RES_CTLR_KMEM) && defined(CONFIG_NET)
-extern struct jump_label_key memcg_socket_limit_enabled;
+extern struct static_key memcg_socket_limit_enabled;
static inline struct cg_proto *parent_cg_proto(struct proto *proto,
struct cg_proto *cg_proto)
{
return proto->proto_cgroup(parent_mem_cgroup(cg_proto->memcg));
}
-#define mem_cgroup_sockets_enabled static_branch(&memcg_socket_limit_enabled)
+#define mem_cgroup_sockets_enabled static_key_false(&memcg_socket_limit_enabled)
#else
#define mem_cgroup_sockets_enabled 0
static inline struct cg_proto *parent_cg_proto(struct proto *proto,
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 7c3b9de..5e0f8bb 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -128,7 +128,7 @@ enum event_type_t {
* perf_sched_events : >0 events exist
* perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
*/
-struct jump_label_key_deferred perf_sched_events __read_mostly;
+struct static_key_deferred perf_sched_events __read_mostly;
static DEFINE_PER_CPU(atomic_t, perf_cgroup_events);

static atomic_t nr_mmap_events __read_mostly;
@@ -2769,7 +2769,7 @@ static void free_event(struct perf_event *event)

if (!event->parent) {
if (event->attach_state & PERF_ATTACH_TASK)
- jump_label_dec_deferred(&perf_sched_events);
+ static_key_slow_dec_deferred(&perf_sched_events);
if (event->attr.mmap || event->attr.mmap_data)
atomic_dec(&nr_mmap_events);
if (event->attr.comm)
@@ -2780,7 +2780,7 @@ static void free_event(struct perf_event *event)
put_callchain_buffers();
if (is_cgroup_event(event)) {
atomic_dec(&per_cpu(perf_cgroup_events, event->cpu));
- jump_label_dec_deferred(&perf_sched_events);
+ static_key_slow_dec_deferred(&perf_sched_events);
}
}

@@ -4982,7 +4982,7 @@ fail:
return err;
}

-struct jump_label_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
+struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];

static void sw_perf_event_destroy(struct perf_event *event)
{
@@ -4990,7 +4990,7 @@ static void sw_perf_event_destroy(struct perf_event *event)

WARN_ON(event->parent);

- jump_label_dec(&perf_swevent_enabled[event_id]);
+ static_key_slow_dec(&perf_swevent_enabled[event_id]);
swevent_hlist_put(event);
}

@@ -5020,7 +5020,7 @@ static int perf_swevent_init(struct perf_event *event)
if (err)
return err;

- jump_label_inc(&perf_swevent_enabled[event_id]);
+ static_key_slow_inc(&perf_swevent_enabled[event_id]);
event->destroy = sw_perf_event_destroy;
}

@@ -5843,7 +5843,7 @@ done:

if (!event->parent) {
if (event->attach_state & PERF_ATTACH_TASK)
- jump_label_inc(&perf_sched_events.key);
+ static_key_slow_inc(&perf_sched_events.key);
if (event->attr.mmap || event->attr.mmap_data)
atomic_inc(&nr_mmap_events);
if (event->attr.comm)
@@ -6081,7 +6081,7 @@ SYSCALL_DEFINE5(perf_event_open,
* - that may need work on context switch
*/
atomic_inc(&per_cpu(perf_cgroup_events, event->cpu));
- jump_label_inc(&perf_sched_events.key);
+ static_key_slow_inc(&perf_sched_events.key);
}

/*
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 543782e..1cc32e3 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -12,7 +12,7 @@
#include <linux/slab.h>
#include <linux/sort.h>
#include <linux/err.h>
-#include <linux/jump_label.h>
+#include <linux/static_key.h>

#ifdef HAVE_JUMP_LABEL

@@ -29,10 +29,11 @@ void jump_label_unlock(void)
mutex_unlock(&jump_label_mutex);
}

-bool jump_label_enabled(struct jump_label_key *key)
+bool static_key_true(struct static_key *key)
{
- return !!atomic_read(&key->enabled);
+ return (atomic_read(&key->enabled) > 0);
}
+EXPORT_SYMBOL_GPL(static_key_true);

static int jump_label_cmp(const void *a, const void *b)
{
@@ -58,22 +59,26 @@ jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop)
sort(start, size, sizeof(struct jump_entry), jump_label_cmp, NULL);
}

-static void jump_label_update(struct jump_label_key *key, int enable);
+static void jump_label_update(struct static_key *key, int enable);

-void jump_label_inc(struct jump_label_key *key)
+void static_key_slow_inc(struct static_key *key)
{
if (atomic_inc_not_zero(&key->enabled))
return;

jump_label_lock();
- if (atomic_read(&key->enabled) == 0)
- jump_label_update(key, JUMP_LABEL_ENABLE);
+ if (atomic_read(&key->enabled) == 0) {
+ if (!jump_label_get_branch_default(key))
+ jump_label_update(key, JUMP_LABEL_ENABLE);
+ else
+ jump_label_update(key, JUMP_LABEL_DISABLE);
+ }
atomic_inc(&key->enabled);
jump_label_unlock();
}
-EXPORT_SYMBOL_GPL(jump_label_inc);
+EXPORT_SYMBOL_GPL(static_key_slow_inc);

-static void __jump_label_dec(struct jump_label_key *key,
+static void __static_key_slow_dec(struct static_key *key,
unsigned long rate_limit, struct delayed_work *work)
{
if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex)) {
@@ -85,32 +90,35 @@ static void __jump_label_dec(struct jump_label_key *key,
if (rate_limit) {
atomic_inc(&key->enabled);
schedule_delayed_work(work, rate_limit);
- } else
- jump_label_update(key, JUMP_LABEL_DISABLE);
-
+ } else {
+ if (!jump_label_get_branch_default(key))
+ jump_label_update(key, JUMP_LABEL_DISABLE);
+ else
+ jump_label_update(key, JUMP_LABEL_ENABLE);
+ }
jump_label_unlock();
}
-EXPORT_SYMBOL_GPL(jump_label_dec);

static void jump_label_update_timeout(struct work_struct *work)
{
- struct jump_label_key_deferred *key =
- container_of(work, struct jump_label_key_deferred, work.work);
- __jump_label_dec(&key->key, 0, NULL);
+ struct static_key_deferred *key =
+ container_of(work, struct static_key_deferred, work.work);
+ __static_key_slow_dec(&key->key, 0, NULL);
}

-void jump_label_dec(struct jump_label_key *key)
+void static_key_slow_dec(struct static_key *key)
{
- __jump_label_dec(key, 0, NULL);
+ __static_key_slow_dec(key, 0, NULL);
}
+EXPORT_SYMBOL_GPL(static_key_slow_dec);

-void jump_label_dec_deferred(struct jump_label_key_deferred *key)
+void static_key_slow_dec_deferred(struct static_key_deferred *key)
{
- __jump_label_dec(&key->key, key->timeout, &key->work);
+ __static_key_slow_dec(&key->key, key->timeout, &key->work);
}
+EXPORT_SYMBOL_GPL(static_key_slow_dec_deferred);

-
-void jump_label_rate_limit(struct jump_label_key_deferred *key,
+void jump_label_rate_limit(struct static_key_deferred *key,
unsigned long rl)
{
key->timeout = rl;
@@ -153,7 +161,7 @@ void __weak __init_or_module arch_jump_label_transform_static(struct jump_entry
arch_jump_label_transform(entry, type);
}

-static void __jump_label_update(struct jump_label_key *key,
+static void __jump_label_update(struct static_key *key,
struct jump_entry *entry,
struct jump_entry *stop, int enable)
{
@@ -170,27 +178,40 @@ static void __jump_label_update(struct jump_label_key *key,
}
}

+static enum jump_label_type jump_label_type(struct static_key *key)
+{
+ bool true_branch = jump_label_get_branch_default(key);
+ bool state = static_key_true(key);
+
+ if ((!true_branch && state) || (true_branch && !state))
+ return JUMP_LABEL_ENABLE;
+
+ return JUMP_LABEL_DISABLE;
+}
+
void __init jump_label_init(void)
{
struct jump_entry *iter_start = __start___jump_table;
struct jump_entry *iter_stop = __stop___jump_table;
- struct jump_label_key *key = NULL;
+ struct static_key *key = NULL;
struct jump_entry *iter;

jump_label_lock();
jump_label_sort_entries(iter_start, iter_stop);

for (iter = iter_start; iter < iter_stop; iter++) {
- struct jump_label_key *iterk;
+ struct static_key *iterk;

- iterk = (struct jump_label_key *)(unsigned long)iter->key;
- arch_jump_label_transform_static(iter, jump_label_enabled(iterk) ?
- JUMP_LABEL_ENABLE : JUMP_LABEL_DISABLE);
+ iterk = (struct static_key *)(unsigned long)iter->key;
+ arch_jump_label_transform_static(iter, jump_label_type(iterk));
if (iterk == key)
continue;

key = iterk;
- key->entries = iter;
+ /*
+ * Set key->entries to iter, but preserve JUMP_LABEL_TRUE_BRANCH.
+ */
+ *((unsigned long *)&key->entries) += (unsigned long)iter;
#ifdef CONFIG_MODULES
key->next = NULL;
#endif
@@ -200,8 +221,8 @@ void __init jump_label_init(void)

#ifdef CONFIG_MODULES

-struct jump_label_mod {
- struct jump_label_mod *next;
+struct static_key_mod {
+ struct static_key_mod *next;
struct jump_entry *entries;
struct module *mod;
};
@@ -221,9 +242,9 @@ static int __jump_label_mod_text_reserved(void *start, void *end)
start, end);
}

-static void __jump_label_mod_update(struct jump_label_key *key, int enable)
+static void __jump_label_mod_update(struct static_key *key, int enable)
{
- struct jump_label_mod *mod = key->next;
+ struct static_key_mod *mod = key->next;

while (mod) {
struct module *m = mod->mod;
@@ -254,11 +275,7 @@ void jump_label_apply_nops(struct module *mod)
return;

for (iter = iter_start; iter < iter_stop; iter++) {
- struct jump_label_key *iterk;
-
- iterk = (struct jump_label_key *)(unsigned long)iter->key;
- arch_jump_label_transform_static(iter, jump_label_enabled(iterk) ?
- JUMP_LABEL_ENABLE : JUMP_LABEL_DISABLE);
+ arch_jump_label_transform_static(iter, JUMP_LABEL_DISABLE);
}
}

@@ -267,8 +284,8 @@ static int jump_label_add_module(struct module *mod)
struct jump_entry *iter_start = mod->jump_entries;
struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
struct jump_entry *iter;
- struct jump_label_key *key = NULL;
- struct jump_label_mod *jlm;
+ struct static_key *key = NULL;
+ struct static_key_mod *jlm;

/* if the module doesn't have jump label entries, just return */
if (iter_start == iter_stop)
@@ -277,28 +294,30 @@ static int jump_label_add_module(struct module *mod)
jump_label_sort_entries(iter_start, iter_stop);

for (iter = iter_start; iter < iter_stop; iter++) {
- if (iter->key == (jump_label_t)(unsigned long)key)
- continue;
+ struct static_key *iterk;

- key = (struct jump_label_key *)(unsigned long)iter->key;
+ iterk = (struct static_key *)(unsigned long)iter->key;
+ if (iterk == key)
+ continue;

+ key = iterk;
if (__module_address(iter->key) == mod) {
- atomic_set(&key->enabled, 0);
- key->entries = iter;
+ /*
+ * Set key->entries to iter, but preserve JUMP_LABEL_TRUE_BRANCH.
+ */
+ *((unsigned long *)&key->entries) += (unsigned long)iter;
key->next = NULL;
continue;
}
-
- jlm = kzalloc(sizeof(struct jump_label_mod), GFP_KERNEL);
+ jlm = kzalloc(sizeof(struct static_key_mod), GFP_KERNEL);
if (!jlm)
return -ENOMEM;
-
jlm->mod = mod;
jlm->entries = iter;
jlm->next = key->next;
key->next = jlm;

- if (jump_label_enabled(key))
+ if (jump_label_type(key) == JUMP_LABEL_ENABLE)
__jump_label_update(key, iter, iter_stop, JUMP_LABEL_ENABLE);
}

@@ -310,14 +329,14 @@ static void jump_label_del_module(struct module *mod)
struct jump_entry *iter_start = mod->jump_entries;
struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
struct jump_entry *iter;
- struct jump_label_key *key = NULL;
- struct jump_label_mod *jlm, **prev;
+ struct static_key *key = NULL;
+ struct static_key_mod *jlm, **prev;

for (iter = iter_start; iter < iter_stop; iter++) {
if (iter->key == (jump_label_t)(unsigned long)key)
continue;

- key = (struct jump_label_key *)(unsigned long)iter->key;
+ key = (struct static_key *)(unsigned long)iter->key;

if (__module_address(iter->key) == mod)
continue;
@@ -419,9 +438,10 @@ int jump_label_text_reserved(void *start, void *end)
return ret;
}

-static void jump_label_update(struct jump_label_key *key, int enable)
+static void jump_label_update(struct static_key *key, int enable)
{
- struct jump_entry *entry = key->entries, *stop = __stop___jump_table;
+ struct jump_entry *stop = __stop___jump_table;
+ struct jump_entry *entry = jump_label_get_entries(key);

#ifdef CONFIG_MODULES
struct module *mod = __module_address((unsigned long)key);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5255c9d..05fb5df 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -162,13 +162,13 @@ static int sched_feat_show(struct seq_file *m, void *v)

#ifdef HAVE_JUMP_LABEL

-#define jump_label_key__true jump_label_key_enabled
-#define jump_label_key__false jump_label_key_disabled
+#define jump_label_key__true STATIC_KEY_INIT_TRUE
+#define jump_label_key__false STATIC_KEY_INIT_FALSE

#define SCHED_FEAT(name, enabled) \
jump_label_key__##enabled ,

-struct jump_label_key sched_feat_keys[__SCHED_FEAT_NR] = {
+struct static_key sched_feat_keys[__SCHED_FEAT_NR] = {
#include "features.h"
};

@@ -176,14 +176,14 @@ struct jump_label_key sched_feat_keys[__SCHED_FEAT_NR] = {

static void sched_feat_disable(int i)
{
- if (jump_label_enabled(&sched_feat_keys[i]))
- jump_label_dec(&sched_feat_keys[i]);
+ if (static_key_true(&sched_feat_keys[i]))
+ static_key_slow_dec(&sched_feat_keys[i]);
}

static void sched_feat_enable(int i)
{
- if (!jump_label_enabled(&sched_feat_keys[i]))
- jump_label_inc(&sched_feat_keys[i]);
+ if (!static_key_true(&sched_feat_keys[i]))
+ static_key_slow_inc(&sched_feat_keys[i]);
}
#else
static void sched_feat_disable(int i) { };
@@ -894,7 +894,7 @@ static void update_rq_clock_task(struct rq *rq, s64 delta)
delta -= irq_delta;
#endif
#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
- if (static_branch((&paravirt_steal_rq_enabled))) {
+ if (static_key_false((&paravirt_steal_rq_enabled))) {
u64 st;

steal = paravirt_steal_clock(cpu_of(rq));
@@ -2756,7 +2756,7 @@ void account_idle_time(cputime_t cputime)
static __always_inline bool steal_account_process_tick(void)
{
#ifdef CONFIG_PARAVIRT
- if (static_branch(&paravirt_steal_enabled)) {
+ if (static_key_false(&paravirt_steal_enabled)) {
u64 steal, st = 0;

steal = paravirt_steal_clock(smp_processor_id());
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 7c6414f..423547a 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1399,20 +1399,20 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
#ifdef CONFIG_CFS_BANDWIDTH

#ifdef HAVE_JUMP_LABEL
-static struct jump_label_key __cfs_bandwidth_used;
+static struct static_key __cfs_bandwidth_used;

static inline bool cfs_bandwidth_used(void)
{
- return static_branch(&__cfs_bandwidth_used);
+ return static_key_false(&__cfs_bandwidth_used);
}

void account_cfs_bandwidth_used(int enabled, int was_enabled)
{
/* only need to count groups transitioning between enabled/!enabled */
if (enabled && !was_enabled)
- jump_label_inc(&__cfs_bandwidth_used);
+ static_key_slow_inc(&__cfs_bandwidth_used);
else if (!enabled && was_enabled)
- jump_label_dec(&__cfs_bandwidth_used);
+ static_key_slow_dec(&__cfs_bandwidth_used);
}
#else /* HAVE_JUMP_LABEL */
static bool cfs_bandwidth_used(void)
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 98c0c26..b4cd6d8 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -611,7 +611,7 @@ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
* Tunables that become constants when CONFIG_SCHED_DEBUG is off:
*/
#ifdef CONFIG_SCHED_DEBUG
-# include <linux/jump_label.h>
+# include <linux/static_key.h>
# define const_debug __read_mostly
#else
# define const_debug const
@@ -630,18 +630,18 @@ enum {
#undef SCHED_FEAT

#if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
-static __always_inline bool static_branch__true(struct jump_label_key *key)
+static __always_inline bool static_branch__true(struct static_key *key)
{
- return likely(static_branch(key)); /* Not out of line branch. */
+ return static_key_true(key); /* Not out of line branch. */
}

-static __always_inline bool static_branch__false(struct jump_label_key *key)
+static __always_inline bool static_branch__false(struct static_key *key)
{
- return unlikely(static_branch(key)); /* Out of line branch. */
+ return static_key_false(key); /* Out of line branch. */
}

#define SCHED_FEAT(name, enabled) \
-static __always_inline bool static_branch_##name(struct jump_label_key *key) \
+static __always_inline bool static_branch_##name(struct static_key *key) \
{ \
return static_branch__##enabled(key); \
}
@@ -650,7 +650,7 @@ static __always_inline bool static_branch_##name(struct jump_label_key *key) \

#undef SCHED_FEAT

-extern struct jump_label_key sched_feat_keys[__SCHED_FEAT_NR];
+extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
#define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
#else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index f1539de..5e37c26 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -25,7 +25,7 @@
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/sched.h>
-#include <linux/jump_label.h>
+#include <linux/static_key.h>

extern struct tracepoint * const __start___tracepoints_ptrs[];
extern struct tracepoint * const __stop___tracepoints_ptrs[];
@@ -256,9 +256,9 @@ static void set_tracepoint(struct tracepoint_entry **entry,
{
WARN_ON(strcmp((*entry)->name, elem->name) != 0);

- if (elem->regfunc && !jump_label_enabled(&elem->key) && active)
+ if (elem->regfunc && !static_key_true(&elem->key) && active)
elem->regfunc();
- else if (elem->unregfunc && jump_label_enabled(&elem->key) && !active)
+ else if (elem->unregfunc && static_key_true(&elem->key) && !active)
elem->unregfunc();

/*
@@ -269,10 +269,10 @@ static void set_tracepoint(struct tracepoint_entry **entry,
* is used.
*/
rcu_assign_pointer(elem->funcs, (*entry)->funcs);
- if (active && !jump_label_enabled(&elem->key))
- jump_label_inc(&elem->key);
- else if (!active && jump_label_enabled(&elem->key))
- jump_label_dec(&elem->key);
+ if (active && !static_key_true(&elem->key))
+ static_key_slow_inc(&elem->key);
+ else if (!active && static_key_true(&elem->key))
+ static_key_slow_dec(&elem->key);
}

/*
@@ -283,11 +283,11 @@ static void set_tracepoint(struct tracepoint_entry **entry,
*/
static void disable_tracepoint(struct tracepoint *elem)
{
- if (elem->unregfunc && jump_label_enabled(&elem->key))
+ if (elem->unregfunc && static_key_true(&elem->key))
elem->unregfunc();

- if (jump_label_enabled(&elem->key))
- jump_label_dec(&elem->key);
+ if (static_key_true(&elem->key))
+ static_key_slow_dec(&elem->key);
rcu_assign_pointer(elem->funcs, NULL);
}

diff --git a/net/core/dev.c b/net/core/dev.c
index 115dee1..da7ce7f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -134,7 +134,7 @@
#include <linux/inetdevice.h>
#include <linux/cpu_rmap.h>
#include <linux/net_tstamp.h>
-#include <linux/jump_label.h>
+#include <linux/static_key.h>
#include <net/flow_keys.h>

#include "net-sysfs.h"
@@ -1441,11 +1441,11 @@ int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
}
EXPORT_SYMBOL(call_netdevice_notifiers);

-static struct jump_label_key netstamp_needed __read_mostly;
+static struct static_key netstamp_needed __read_mostly;
#ifdef HAVE_JUMP_LABEL
-/* We are not allowed to call jump_label_dec() from irq context
+/* We are not allowed to call static_key_slow_dec() from irq context
* If net_disable_timestamp() is called from irq context, defer the
- * jump_label_dec() calls.
+ * static_key_slow_dec() calls.
*/
static atomic_t netstamp_needed_deferred;
#endif
@@ -1457,12 +1457,12 @@ void net_enable_timestamp(void)

if (deferred) {
while (--deferred)
- jump_label_dec(&netstamp_needed);
+ static_key_slow_dec(&netstamp_needed);
return;
}
#endif
WARN_ON(in_interrupt());
- jump_label_inc(&netstamp_needed);
+ static_key_slow_inc(&netstamp_needed);
}
EXPORT_SYMBOL(net_enable_timestamp);

@@ -1474,19 +1474,19 @@ void net_disable_timestamp(void)
return;
}
#endif
- jump_label_dec(&netstamp_needed);
+ static_key_slow_dec(&netstamp_needed);
}
EXPORT_SYMBOL(net_disable_timestamp);

static inline void net_timestamp_set(struct sk_buff *skb)
{
skb->tstamp.tv64 = 0;
- if (static_branch(&netstamp_needed))
+ if (static_key_false(&netstamp_needed))
__net_timestamp(skb);
}

#define net_timestamp_check(COND, SKB) \
- if (static_branch(&netstamp_needed)) { \
+ if (static_key_false(&netstamp_needed)) { \
if ((COND) && !(SKB)->tstamp.tv64) \
__net_timestamp(SKB); \
} \
@@ -2660,7 +2660,7 @@ EXPORT_SYMBOL(__skb_get_rxhash);
struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
EXPORT_SYMBOL(rps_sock_flow_table);

-struct jump_label_key rps_needed __read_mostly;
+struct static_key rps_needed __read_mostly;

static struct rps_dev_flow *
set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
@@ -2945,7 +2945,7 @@ int netif_rx(struct sk_buff *skb)

trace_netif_rx(skb);
#ifdef CONFIG_RPS
- if (static_branch(&rps_needed)) {
+ if (static_key_false(&rps_needed)) {
struct rps_dev_flow voidflow, *rflow = &voidflow;
int cpu;

@@ -3309,7 +3309,7 @@ int netif_receive_skb(struct sk_buff *skb)
return NET_RX_SUCCESS;

#ifdef CONFIG_RPS
- if (static_branch(&rps_needed)) {
+ if (static_key_false(&rps_needed)) {
struct rps_dev_flow voidflow, *rflow = &voidflow;
int cpu, ret;

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index a1727cd..4955862 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -608,10 +608,10 @@ static ssize_t store_rps_map(struct netdev_rx_queue *queue,
spin_unlock(&rps_map_lock);

if (map)
- jump_label_inc(&rps_needed);
+ static_key_slow_inc(&rps_needed);
if (old_map) {
kfree_rcu(old_map, rcu);
- jump_label_dec(&rps_needed);
+ static_key_slow_dec(&rps_needed);
}
free_cpumask_var(mask);
return len;
diff --git a/net/core/sock.c b/net/core/sock.c
index 3e81fd2..3a4e581 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -111,7 +111,7 @@
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/user_namespace.h>
-#include <linux/jump_label.h>
+#include <linux/static_key.h>
#include <linux/memcontrol.h>

#include <asm/uaccess.h>
@@ -184,7 +184,7 @@ void mem_cgroup_sockets_destroy(struct cgroup *cgrp, struct cgroup_subsys *ss)
static struct lock_class_key af_family_keys[AF_MAX];
static struct lock_class_key af_family_slock_keys[AF_MAX];

-struct jump_label_key memcg_socket_limit_enabled;
+struct static_key memcg_socket_limit_enabled;
EXPORT_SYMBOL(memcg_socket_limit_enabled);

/*
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
index d05559d..0c28508 100644
--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c
@@ -69,9 +69,9 @@ static int rps_sock_flow_sysctl(ctl_table *table, int write,
if (sock_table != orig_sock_table) {
rcu_assign_pointer(rps_sock_flow_table, sock_table);
if (sock_table)
- jump_label_inc(&rps_needed);
+ static_key_slow_inc(&rps_needed);
if (orig_sock_table) {
- jump_label_dec(&rps_needed);
+ static_key_slow_dec(&rps_needed);
synchronize_rcu();
vfree(orig_sock_table);
}
diff --git a/net/ipv4/tcp_memcontrol.c b/net/ipv4/tcp_memcontrol.c
index 4997878..602fb30 100644
--- a/net/ipv4/tcp_memcontrol.c
+++ b/net/ipv4/tcp_memcontrol.c
@@ -111,7 +111,7 @@ void tcp_destroy_cgroup(struct cgroup *cgrp, struct cgroup_subsys *ss)
val = res_counter_read_u64(&tcp->tcp_memory_allocated, RES_LIMIT);

if (val != RESOURCE_MAX)
- jump_label_dec(&memcg_socket_limit_enabled);
+ static_key_slow_dec(&memcg_socket_limit_enabled);
}
EXPORT_SYMBOL(tcp_destroy_cgroup);

@@ -143,9 +143,9 @@ static int tcp_update_limit(struct mem_cgroup *memcg, u64 val)
net->ipv4.sysctl_tcp_mem[i]);

if (val == RESOURCE_MAX && old_lim != RESOURCE_MAX)
- jump_label_dec(&memcg_socket_limit_enabled);
+ static_key_slow_dec(&memcg_socket_limit_enabled);
else if (old_lim == RESOURCE_MAX && val != RESOURCE_MAX)
- jump_label_inc(&memcg_socket_limit_enabled);
+ static_key_slow_inc(&memcg_socket_limit_enabled);

return 0;
}
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index b4e8ff0..e1b7e05 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -56,7 +56,7 @@ struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS] __read_mostly;
EXPORT_SYMBOL(nf_hooks);

#if defined(CONFIG_JUMP_LABEL)
-struct jump_label_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
+struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
EXPORT_SYMBOL(nf_hooks_needed);
#endif

@@ -77,7 +77,7 @@ int nf_register_hook(struct nf_hook_ops *reg)
list_add_rcu(&reg->list, elem->list.prev);
mutex_unlock(&nf_hook_mutex);
#if defined(CONFIG_JUMP_LABEL)
- jump_label_inc(&nf_hooks_needed[reg->pf][reg->hooknum]);
+ static_key_slow_inc(&nf_hooks_needed[reg->pf][reg->hooknum]);
#endif
return 0;
}
@@ -89,7 +89,7 @@ void nf_unregister_hook(struct nf_hook_ops *reg)
list_del_rcu(&reg->list);
mutex_unlock(&nf_hook_mutex);
#if defined(CONFIG_JUMP_LABEL)
- jump_label_dec(&nf_hooks_needed[reg->pf][reg->hooknum]);
+ static_key_slow_dec(&nf_hooks_needed[reg->pf][reg->hooknum]);
#endif
synchronize_net();
}

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  Last update: 2012-02-24 09:01    [from the cache]
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