[PATCH] rseq: always inline rseq_debug_syscall_return()

[PATCH] rseq: always inline rseq_debug_syscall_return()

[Eric Dumazet]

To get full benefit of commit eaa9088d568c ("rseq: Use static branch
for syscall exit debug when GENERIC_IRQ_ENTRY=y"), clang needs
__always_inline instead of inline qualifier.

Tested:

for i in {1..10}; do taskset -c 4 perf5 bench syscall basic -l 100000000 | grep "ops/sec"; done

Before:
     15,490,350 ops/sec
     15,564,199 ops/sec
     15,450,324 ops/sec
     15,443,986 ops/sec
     15,519,631 ops/sec
     15,400,475 ops/sec
     15,282,792 ops/sec
     15,464,758 ops/sec
     15,344,973 ops/sec
     15,283,429 ops/sec

After:
     15,940,189 ops/sec
     15,971,037 ops/sec
     15,963,332 ops/sec
     15,897,626 ops/sec
     15,824,637 ops/sec
     15,719,760 ops/sec
     15,823,175 ops/sec
     15,745,080 ops/sec
     15,930,646 ops/sec
     15,906,730 ops/sec

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 include/linux/rseq_entry.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/rseq_entry.h b/include/linux/rseq_entry.h
index c92167ff8a7fbd1a0771d5a79c71ee8bc4a0f8bf..a36b472627dec83a9a196eb33b83e8d39061ffbe 100644
--- a/include/linux/rseq_entry.h
+++ b/include/linux/rseq_entry.h
@@ -596,7 +596,7 @@ static __always_inline void rseq_exit_to_user_mode_legacy(void)
 
 void __rseq_debug_syscall_return(struct pt_regs *regs);
 
-static inline void rseq_debug_syscall_return(struct pt_regs *regs)
+static __always_inline void rseq_debug_syscall_return(struct pt_regs *regs)
 {
 	if (static_branch_unlikely(&rseq_debug_enabled))
 		__rseq_debug_syscall_return(regs);
-- 
2.52.0.223.gf5cc29aaa4-goog

Re: [PATCH] rseq: always inline rseq_debug_syscall_return()

[Mathieu Desnoyers]

On 2025-12-05 05:07, Eric Dumazet wrote:
> To get full benefit of commit eaa9088d568c ("rseq: Use static branch
> for syscall exit debug when GENERIC_IRQ_ENTRY=y"), clang needs
> __always_inline instead of inline qualifier.
> ...
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

-- 
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com

[tip: core/urgent] rseq: Always inline rseq_debug_syscall_return()

[tip-bot2 for Eric Dumazet]

The following commit has been merged into the core/urgent branch of tip:

Commit-ID:     ad9c647ad7627d1ced814fca6d75d046b5a04d6b
Gitweb:        https://git.kernel.org/tip/ad9c647ad7627d1ced814fca6d75d046b5a04d6b
Author:        Eric Dumazet <edumazet@google.com>
AuthorDate:    Fri, 05 Dec 2025 10:07:53 
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Wed, 10 Dec 2025 10:10:05 +09:00

rseq: Always inline rseq_debug_syscall_return()

To get the full benefit of commit eaa9088d568c ("rseq: Use static branch
for syscall exit debug when GENERIC_IRQ_ENTRY=y"), clang needs
__always_inline instead of a plain inline qualifier.

for i in {1..10}; do taskset -c 4 perf5 bench syscall basic -l 100000000 | grep "ops/sec"; done

      	 Before	     After
ops/sec  15424491    15872221   +2.9%

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20251205100753.4073221-1-edumazet@google.com
---
 include/linux/rseq_entry.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/rseq_entry.h b/include/linux/rseq_entry.h
index c92167f..a36b472 100644
--- a/include/linux/rseq_entry.h
+++ b/include/linux/rseq_entry.h
@@ -596,7 +596,7 @@ static __always_inline void rseq_exit_to_user_mode_legacy(void)
 
 void __rseq_debug_syscall_return(struct pt_regs *regs);
 
-static inline void rseq_debug_syscall_return(struct pt_regs *regs)
+static __always_inline void rseq_debug_syscall_return(struct pt_regs *regs)
 {
 	if (static_branch_unlikely(&rseq_debug_enabled))
 		__rseq_debug_syscall_return(regs);

[tip: core/urgent] rseq: Always inline rseq_debug_syscall_return()

[tip-bot2 for Eric Dumazet]

The following commit has been merged into the core/urgent branch of tip:

Commit-ID:     f1de49094b9e0b44f85a0f8b77bc27d8ca222e3c
Gitweb:        https://git.kernel.org/tip/f1de49094b9e0b44f85a0f8b77bc27d8ca222e3c
Author:        Eric Dumazet <edumazet@google.com>
AuthorDate:    Fri, 05 Dec 2025 10:07:53 
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 12 Dec 2025 10:07:06 +01:00

rseq: Always inline rseq_debug_syscall_return()

To get the full benefit of:

  eaa9088d568c ("rseq: Use static branch for syscall exit debug when GENERIC_IRQ_ENTRY=y")

clang needs an __always_inline instead of a plain inline qualifier:

	$ for i in {1..10}; do taskset -c 4 perf5 bench syscall basic -l 100000000 | grep "ops/sec"; done

		 Before	     After
	ops/sec  15424491    15872221   +2.9%

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20251205100753.4073221-1-edumazet@google.com
---
 include/linux/rseq_entry.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/rseq_entry.h b/include/linux/rseq_entry.h
index c92167f..a36b472 100644
--- a/include/linux/rseq_entry.h
+++ b/include/linux/rseq_entry.h
@@ -596,7 +596,7 @@ static __always_inline void rseq_exit_to_user_mode_legacy(void)
 
 void __rseq_debug_syscall_return(struct pt_regs *regs);
 
-static inline void rseq_debug_syscall_return(struct pt_regs *regs)
+static __always_inline void rseq_debug_syscall_return(struct pt_regs *regs)
 {
 	if (static_branch_unlikely(&rseq_debug_enabled))
 		__rseq_debug_syscall_return(regs);

[tip: core/urgent] rseq: Always inline rseq_debug_syscall_return()

[tip-bot2 for Eric Dumazet]

The following commit has been merged into the core/urgent branch of tip:

Commit-ID:     bdae29d6512ddc589200b9ae6bda467bdbab863d
Gitweb:        https://git.kernel.org/tip/bdae29d6512ddc589200b9ae6bda467bdbab863d
Author:        Eric Dumazet <edumazet@google.com>
AuthorDate:    Fri, 05 Dec 2025 10:07:53 
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 12 Dec 2025 10:26:26 +01:00

rseq: Always inline rseq_debug_syscall_return()

To get the full benefit of:

  eaa9088d568c ("rseq: Use static branch for syscall exit debug when GENERIC_IRQ_ENTRY=y")

clang needs an __always_inline instead of a plain inline qualifier:

	$ for i in {1..10}; do taskset -c 4 perf5 bench syscall basic -l 100000000 | grep "ops/sec"; done

		 Before	     After
	ops/sec  15424491    15872221   +2.9%

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20251205100753.4073221-1-edumazet@google.com
---
 include/linux/rseq_entry.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/rseq_entry.h b/include/linux/rseq_entry.h
index c92167f..a36b472 100644
--- a/include/linux/rseq_entry.h
+++ b/include/linux/rseq_entry.h
@@ -596,7 +596,7 @@ static __always_inline void rseq_exit_to_user_mode_legacy(void)
 
 void __rseq_debug_syscall_return(struct pt_regs *regs);
 
-static inline void rseq_debug_syscall_return(struct pt_regs *regs)
+static __always_inline void rseq_debug_syscall_return(struct pt_regs *regs)
 {
 	if (static_branch_unlikely(&rseq_debug_enabled))
 		__rseq_debug_syscall_return(regs);