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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, John Stultz <john.stultz@linaro.org>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	Andy Lutomirski <luto@kernel.org>,
	Christophe Leroy <christophe.leroy@c-s.fr>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Juergen Gross <jgross@suse.com>,
	Michael Kelley <mikelley@microsoft.com>,
	Sasha Levin <sashal@kernel.org>,
	Ralf Baechle <ralf@linux-mips.org>,
	Paul Burton <paulburton@kernel.org>,
	James Hogan <jhogan@kernel.org>,
	Russell King <linux@armlinux.org.uk>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Marc Zyngier <maz@kernel.org>, Andrei Vagin <avagin@gmail.com>
Subject: [patch V2 13/17] lib/vdso: Avoid highres update if clocksource is not VDSO capable
Date: Fri, 07 Feb 2020 13:39:00 +0100	[thread overview]
Message-ID: <20200207124403.563379423@linutronix.de> (raw)
In-Reply-To: 20200207123847.339896630@linutronix.de

From: Thomas Gleixner <tglx@linutronix.de>

If the current clocksource is not VDSO capable there is no point in
updating the high resolution parts of the VDSO data.

Replace the architecture specific check with a check for a VDSO capable
clocksource and skip the update if there is none.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/arm/include/asm/vdso/vsyscall.h |    7 -------
 include/asm-generic/vdso/vsyscall.h  |    7 -------
 kernel/time/vsyscall.c               |    6 +++---
 3 files changed, 3 insertions(+), 17 deletions(-)

--- a/arch/arm/include/asm/vdso/vsyscall.h
+++ b/arch/arm/include/asm/vdso/vsyscall.h
@@ -22,13 +22,6 @@ struct vdso_data *__arm_get_k_vdso_data(
 #define __arch_get_k_vdso_data __arm_get_k_vdso_data
 
 static __always_inline
-bool __arm_update_vdso_data(void)
-{
-	return cntvct_ok;
-}
-#define __arch_update_vdso_data __arm_update_vdso_data
-
-static __always_inline
 void __arm_sync_vdso_data(struct vdso_data *vdata)
 {
 	flush_dcache_page(virt_to_page(vdata));
--- a/include/asm-generic/vdso/vsyscall.h
+++ b/include/asm-generic/vdso/vsyscall.h
@@ -11,13 +11,6 @@ static __always_inline struct vdso_data
 }
 #endif /* __arch_get_k_vdso_data */
 
-#ifndef __arch_update_vdso_data
-static __always_inline bool __arch_update_vdso_data(void)
-{
-	return true;
-}
-#endif /* __arch_update_vdso_data */
-
 #ifndef __arch_update_vsyscall
 static __always_inline void __arch_update_vsyscall(struct vdso_data *vdata,
 						   struct timekeeper *tk)
--- a/kernel/time/vsyscall.c
+++ b/kernel/time/vsyscall.c
@@ -105,10 +105,10 @@ void update_vsyscall(struct timekeeper *
 	WRITE_ONCE(vdata[CS_HRES_COARSE].hrtimer_res, hrtimer_resolution);
 
 	/*
-	 * Architectures can opt out of updating the high resolution part
-	 * of the VDSO.
+	 * If the current clocksource is not VDSO capable, then spare the
+	 * update of the high reolution parts.
 	 */
-	if (__arch_update_vdso_data())
+	if (clock_mode != VDSO_CLOCKMODE_NONE)
 		update_vdso_data(vdata, tk);
 
 	__arch_update_vsyscall(vdata, tk);


  parent reply	other threads:[~2020-02-07 13:26 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-07 12:38 [patch V2 00/17] VDSO consolidation Thomas Gleixner
2020-02-07 12:38 ` [patch V2 01/17] x86/vdso: Mark the TSC clocksource path likely Thomas Gleixner
2020-02-14 12:00   ` Vincenzo Frascino
2020-02-17 15:12   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 02/17] ARM: vdso: Remove unused function Thomas Gleixner
2020-02-14 10:21   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 03/17] lib/vdso: Allow the high resolution parts to be compiled out Thomas Gleixner
2020-02-14 11:54   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 04/17] ARM: vdso: Compile high resolution parts conditionally Thomas Gleixner
2020-02-14 11:55   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 05/17] MIPS: " Thomas Gleixner
2020-02-14 11:55   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 06/17] clocksource: Cleanup struct clocksource and documentation Thomas Gleixner
2020-02-14 11:57   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 07/17] x86/vdso: Move VDSO clocksource state tracking to callback Thomas Gleixner
2020-02-14 11:58   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 08/17] clocksource: Add common vdso clock mode storage Thomas Gleixner
2020-02-17 10:36   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 09/17] x86/vdso: Use generic VDSO " Thomas Gleixner
2020-02-14 10:32   ` Paolo Bonzini
2020-02-17 10:57   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 10/17] mips: vdso: " Thomas Gleixner
2020-02-17 10:52   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-17 19:18   ` tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 11/17] ARM/arm64: vdso: Use common vdso " Thomas Gleixner
2020-02-17 10:43   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-17 19:18   ` tip-bot2 for Thomas Gleixner
     [not found]   ` <CGME20200221115643eucas1p12ecb95c6161853a0e7dfe9207db079be@eucas1p1.samsung.com>
2020-02-21 11:56     ` [patch V2 11/17] " Marek Szyprowski
2020-02-21 13:08       ` Vincenzo Frascino
2020-02-21 18:24       ` Vincenzo Frascino
2020-02-07 12:38 ` [patch V2 12/17] lib/vdso: Cleanup clock mode storage leftovers Thomas Gleixner
2020-02-17 11:04   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-17 19:18   ` tip-bot2 for Thomas Gleixner
2020-02-07 12:39 ` Thomas Gleixner [this message]
2020-02-17 11:07   ` [patch V2 13/17] lib/vdso: Avoid highres update if clocksource is not VDSO capable Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-17 19:18   ` tip-bot2 for Thomas Gleixner
2020-02-07 12:39 ` [patch V2 14/17] lib/vdso: Move VCLOCK_TIMENS to vdso_clock_modes Thomas Gleixner
2020-02-17 11:12   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-17 19:18   ` tip-bot2 for Thomas Gleixner
2020-02-07 12:39 ` [patch V2 15/17] lib/vdso: Allow fixed clock mode Thomas Gleixner
2020-02-17 11:14   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Christophe Leroy
2020-02-17 19:18   ` tip-bot2 for Christophe Leroy
2020-02-07 12:39 ` [patch V2 16/17] lib/vdso: Allow architectures to override the ns shift operation Thomas Gleixner
2020-02-17 11:15   ` Vincenzo Frascino
2020-02-07 12:39 ` [patch V2 17/17] lib/vdso: Allow architectures to provide the vdso data pointer Thomas Gleixner
2020-02-17 12:09   ` Vincenzo Frascino

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