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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
	linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Carsten Emde <C.Emde@osadl.org>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	John Kacur <jkacur@redhat.com>,
	Paul Gortmaker <paul.gortmaker@windriver.com>
Subject: [PATCH RT 06/15] ARM: imx: always use TWD on IMX6Q
Date: Tue, 12 Jul 2016 10:29:13 -0400	[thread overview]
Message-ID: <20160712142919.647214235@goodmis.org> (raw)
In-Reply-To: 20160712142907.636678217@goodmis.org

[-- Attachment #1: 0006-ARM-imx-always-use-TWD-on-IMX6Q.patch --]
[-- Type: text/plain, Size: 1127 bytes --]

3.18.36-rt38-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

There is no reason to limit the TWD to be used on SMP kernels only if the
hardware has it available.
On Wandboard i.MX6SOLO, running PREEMPT-RT and cyclictest I see as max
immediately after start in idle:
UP : ~90us
SMP: ~50us
UP + TWD: ~20us.
Based on this numbers I prefer the TWD over the slightly slower MXC
timer.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 arch/arm/mach-imx/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index 11b2957f792b..41792b506b2e 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -605,7 +605,7 @@ config SOC_IMX6Q
 	bool "i.MX6 Quad/DualLite support"
 	select ARM_ERRATA_764369 if SMP
 	select HAVE_ARM_SCU if SMP
-	select HAVE_ARM_TWD if SMP
+	select HAVE_ARM_TWD
 	select PCI_DOMAINS if PCI
 	select PINCTRL_IMX6Q
 	select SOC_IMX6
-- 
2.8.1

  parent reply	other threads:[~2016-07-12 14:29 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-12 14:29 [PATCH RT 00/15] Linux 3.18.36-rt38-rc1 Steven Rostedt
2016-07-12 14:29 ` [PATCH RT 01/15] kvm, rt: change async pagefault code locking for PREEMPT_RT Steven Rostedt
2016-07-12 14:29 ` [PATCH RT 02/15] mm/zsmalloc: Use get/put_cpu_light in zs_map_object()/zs_unmap_object() Steven Rostedt
2016-07-12 14:29 ` [PATCH RT 03/15] net: dev: always take qdiscs busylock in __dev_xmit_skb() Steven Rostedt
2016-07-12 14:29 ` [PATCH RT 04/15] drivers/block/zram: Replace bit spinlocks with rtmutex for -rt Steven Rostedt
2016-07-12 14:29 ` [PATCH RT 05/15] list_bl: fixup bogus lockdep warning Steven Rostedt
2016-07-12 14:29 ` Steven Rostedt [this message]
2016-07-12 14:29 ` [PATCH RT 07/15] drivers/block/zram: fixup compile for !RT Steven Rostedt
2016-07-12 14:29 ` [PATCH RT 08/15] perf/x86/intel/rapl: Make PMU lock raw Steven Rostedt
2016-07-12 14:29 ` [PATCH RT 09/15] sched,preempt: Fix preempt_count manipulations Steven Rostedt
2016-07-12 14:29 ` [PATCH RT 10/15] kernel/printk: Dont try to print from IRQ/NMI region Steven Rostedt
2016-07-12 14:29 ` [PATCH RT 11/15] arm: lazy preempt: correct resched condition Steven Rostedt
2016-07-12 14:29 ` [PATCH RT 12/15] locallock: add local_lock_on() Steven Rostedt
2016-07-12 14:29 ` [PATCH RT 13/15] mm: perform lru_add_drain_all() remotely Steven Rostedt
2016-07-12 14:29 ` [PATCH RT 14/15] trace: correct off by one while recording the trace-event Steven Rostedt
2016-07-12 14:29 ` [PATCH RT 15/15] Linux 3.18.36-rt38-rc1 Steven Rostedt
2016-07-12 23:20 ` Linux 3.18.36-rt38-rc2 Steven Rostedt

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