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From: tip-bot for Thomas Gleixner <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: luto@kernel.org, peterz@infradead.org,
	linux-kernel@vger.kernel.org, torvalds@linux-foundation.org,
	hpa@zytor.com, rostedt@goodmis.org, mingo@kernel.org,
	tglx@linutronix.de, bp@alien8.de
Subject: [tip:x86/apic] x86/smp: Use static key for reschedule interrupt tracing
Date: Tue, 29 Aug 2017 04:09:40 -0700	[thread overview]
Message-ID: <tip-3cd788c1eec4b3659671aa13d335a15102ac4d06@git.kernel.org> (raw)
In-Reply-To: <20170828064957.299808677@linutronix.de>

Commit-ID:  3cd788c1eec4b3659671aa13d335a15102ac4d06
Gitweb:     http://git.kernel.org/tip/3cd788c1eec4b3659671aa13d335a15102ac4d06
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Mon, 28 Aug 2017 08:47:30 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 29 Aug 2017 11:42:27 +0200

x86/smp: Use static key for reschedule interrupt tracing

It's worth to avoid the extra irq_enter()/irq_exit() pair in the case that
the reschedule interrupt tracepoints are disabled.

Use the static key which indicates that exception tracing is enabled. For
now this key is global. It will be optimized in a later step.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170828064957.299808677@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/include/asm/hw_irq.h |  2 +-
 arch/x86/kernel/smp.c         | 40 +++++++++++++++-------------------------
 2 files changed, 16 insertions(+), 26 deletions(-)

diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index 8fb6c22..4626f87 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -48,7 +48,7 @@ extern asmlinkage void call_function_single_interrupt(void);
 
 #ifdef CONFIG_TRACING
 /* Interrupt handlers registered during init_IRQ */
-extern void trace_reschedule_interrupt(void);
+#define trace_reschedule_interrupt	reschedule_interrupt
 #define trace_call_function_interrupt	call_function_interrupt
 #define trace_call_function_single_interrupt	call_function_single_interrupt
 #define trace_thermal_interrupt	thermal_interrupt
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index fb49e10..cfe865b 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -254,37 +254,27 @@ finish:
 }
 
 /*
- * Reschedule call back.
+ * Reschedule call back. KVM uses this interrupt to force a cpu out of
+ * guest mode
  */
-static inline void __smp_reschedule_interrupt(void)
-{
-	inc_irq_stat(irq_resched_count);
-	scheduler_ipi();
-}
-
 __visible void __irq_entry smp_reschedule_interrupt(struct pt_regs *regs)
 {
 	ack_APIC_irq();
-	__smp_reschedule_interrupt();
-	/*
-	 * KVM uses this interrupt to force a cpu out of guest mode
-	 */
-}
-
-__visible void __irq_entry smp_trace_reschedule_interrupt(struct pt_regs *regs)
-{
-	/*
-	 * Need to call irq_enter() before calling the trace point.
-	 * __smp_reschedule_interrupt() calls irq_enter/exit() too (in
-	 * scheduler_ipi(). This is OK, since those functions are allowed
-	 * to nest.
-	 */
-	ipi_entering_ack_irq();
-	trace_reschedule_entry(RESCHEDULE_VECTOR);
 	inc_irq_stat(irq_resched_count);
+
+	if (trace_irqvectors_enabled()) {
+		/*
+		 * scheduler_ipi() might call irq_enter() as well, but
+		 * nested calls are fine.
+		 */
+		irq_enter();
+		trace_reschedule_entry(RESCHEDULE_VECTOR);
+		scheduler_ipi();
+		trace_reschedule_exit(RESCHEDULE_VECTOR);
+		irq_exit();
+		return;
+	}
 	scheduler_ipi();
-	trace_reschedule_exit(RESCHEDULE_VECTOR);
-	exiting_irq();
 }
 
 __visible void __irq_entry smp_call_function_interrupt(struct pt_regs *regs)

  reply	other threads:[~2017-08-29 11:14 UTC|newest]

Thread overview: 95+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-28  6:47 [patch V3 00/44] x86: Cleanup IDT code Thomas Gleixner
2017-08-28  6:47 ` [patch V3 01/44] x86/irq: Remove vector_used_by_percpu_irq() Thomas Gleixner
2017-08-29 11:04   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 02/44] x86/irq: Unexport used_vectors Thomas Gleixner
2017-08-29 11:04   ` [tip:x86/apic] x86/irq: Unexport used_vectors[] tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 03/44] x86/irq: Get rid of the first_system_vector bogisity Thomas Gleixner
2017-08-29 11:04   ` [tip:x86/apic] x86/irq: Get rid of the 'first_system_vector' indirection bogosity tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 04/44] x86/irq: Remove duplicated used_vectors definition Thomas Gleixner
2017-08-29 11:05   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 05/44] x86/boot: Move EISA setup to a proper place Thomas Gleixner
2017-08-29 11:05   ` [tip:x86/apic] x86/boot: Move EISA setup to a separate file tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 06/44] x86/tracing: Introduce a static key for exception tracing Thomas Gleixner
2017-08-29 11:06   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 07/44] x86/traps: Simplify pagefault tracing logic Thomas Gleixner
2017-08-29 11:06   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 08/44] x86/apic: Remove the duplicated tracing version of local_timer_interrupt Thomas Gleixner
2017-08-29 11:07   ` [tip:x86/apic] x86/apic: Remove the duplicated tracing version of local_timer_interrupt() tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 09/44] x86/apic: Use this_cpu_ptr in local_timer_interrupt Thomas Gleixner
2017-08-29 11:07   ` [tip:x86/apic] x86/apic: Use this_cpu_ptr() in local_timer_interrupt() tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 10/44] x86/irq: Get rid of duplicated trace_x86_platform_ipi() code Thomas Gleixner
2017-08-29 11:07   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 11/44] x86/apic: Remove the duplicated tracing versions of interrupts Thomas Gleixner
2017-08-29 11:08   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 12/44] x86/irqwork: Get rid of duplicated tracing interrupt code Thomas Gleixner
2017-08-29 11:08   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 13/44] x86/mce: Remove " Thomas Gleixner
2017-08-29 11:08   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 14/44] x86/smp: Remove pointless duplicated " Thomas Gleixner
2017-08-29 11:09   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 15/44] x86/smp: Use static key for reschedule interrupt tracing Thomas Gleixner
2017-08-29 11:09   ` tip-bot for Thomas Gleixner [this message]
2017-08-28  6:47 ` [patch V3 16/44] x86/idt: Remove tracing idt completely Thomas Gleixner
2017-08-29 11:10   ` [tip:x86/apic] x86/idt: Remove the tracing IDT completely tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 17/44] x86/idt: Cleanup the i386 low level entry macros Thomas Gleixner
2017-08-29 11:10   ` [tip:x86/apic] x86/idt: Clean up " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 18/44] x86/tracing: Disentangle pagefault and resched IPI tracing key Thomas Gleixner
2017-08-29 11:10   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 19/44] x86/ipi: Make platform IPI depend on APIC Thomas Gleixner
2017-08-29 11:11   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 20/44] x86/irq_work: Make it " Thomas Gleixner
2017-08-29 11:11   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 21/44] x86/tracing: Build tracepoints only when they are used Thomas Gleixner
2017-08-29 11:12   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 22/44] x86/idt: Unify gate_struct handling for 32/64bit Thomas Gleixner
2017-08-29 11:12   ` [tip:x86/apic] x86/idt: Unify gate_struct handling for 32/64-bit kernels tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 23/44] x86/percpu: Use static initializer for GDT entry Thomas Gleixner
2017-08-29 11:13   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 24/44] x86/fpu: Use bitfield accessors for desc_struct Thomas Gleixner
2017-08-29 11:13   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 25/44] x86: Replace access to desc_struct:a/b fields Thomas Gleixner
2017-08-29 11:13   ` [tip:x86/apic] x86/asm: " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 26/44] x86/gdt: Use bitfields for initialization Thomas Gleixner
2017-08-29 11:14   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 27/44] x86/ldttss: Cleanup 32bit descriptors Thomas Gleixner
2017-08-29 11:14   ` [tip:x86/apic] x86/ldttss: Clean up 32-bit descriptors tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 28/44] x86/idt: Create file for IDT related code Thomas Gleixner
2017-08-29 11:15   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 29/44] x86/idt: Move 32bit idt_descr to C code Thomas Gleixner
2017-08-29 11:15   ` [tip:x86/apic] x86/idt: Move 32-bit " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 30/44] x86/idt: Remove unused set_trap_gate() Thomas Gleixner
2017-08-29 11:16   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 31/44] x86/idt: Consolidate IDT invalidation Thomas Gleixner
2017-08-29 11:16   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 32/44] x86/idt: Move early IDT handler setup to IDT code Thomas Gleixner
2017-08-29 11:16   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 33/44] x86/idt: Move early IDT setup out of 32bit asm Thomas Gleixner
2017-08-29 11:17   ` [tip:x86/apic] x86/idt: Move early IDT setup out of 32-bit asm tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 34/44] x86/idt: Prepare for table based init Thomas Gleixner
2017-08-29 11:17   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 35/44] x86/idt: Switch early trap init to IDT tables Thomas Gleixner
2017-08-29 11:18   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 36/44] x86/idt: Move debug stack init to table based Thomas Gleixner
2017-08-29 11:18   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 37/44] x86/idt: Move ist stack based traps to table init Thomas Gleixner
2017-08-29 11:18   ` [tip:x86/apic] x86/idt: Move IST " tip-bot for Thomas Gleixner
2017-09-01  6:28     ` Andrei Vagin
2017-09-01  8:26       ` [PATCH] x86/idt: Fix the X86_TRAP_BP gate Ingo Molnar
2017-09-01  8:59         ` Thomas Gleixner
2017-09-01  9:09         ` [tip:x86/apic] " tip-bot for Ingo Molnar
2017-09-01 14:39         ` [PATCH] " Andrei Vagin
2017-08-28  6:47 ` [patch V3 38/44] x86/idt: Move regular trap init to tables Thomas Gleixner
2017-08-29 11:19   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 39/44] x86/idt: Move APIC gate initialization " Thomas Gleixner
2017-08-29 11:19   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 40/44] x86/idt: Move interrupt gate initialization to IDT code Thomas Gleixner
2017-08-29 11:20   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 41/44] x86/idt: Remove unused functions/inlines Thomas Gleixner
2017-08-29 11:20   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 42/44] x86/idt: Deinline setup functions Thomas Gleixner
2017-08-29 11:20   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 43/44] x86/idt: Simplify alloc_intr_gate Thomas Gleixner
2017-08-28 14:35   ` KY Srinivasan
2017-08-29 11:21   ` [tip:x86/apic] x86/idt: Simplify alloc_intr_gate() tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 44/44] x86/idt: Hide set_intr_gate() Thomas Gleixner
2017-08-29 11:21   ` [tip:x86/apic] " tip-bot for Thomas Gleixner

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