From: Will Deacon <will.deacon@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, ard.biesheuvel@linaro.org,
catalin.marinas@arm.com, rml@tech9.net, tglx@linutronix.de,
peterz@infradead.org, schwidefsky@de.ibm.com,
Will Deacon <will.deacon@arm.com>
Subject: [PATCH 1/2] preempt: Move PREEMPT_NEED_RESCHED definition into arch code
Date: Tue, 27 Nov 2018 19:45:01 +0000 [thread overview]
Message-ID: <1543347902-21170-2-git-send-email-will.deacon@arm.com> (raw)
In-Reply-To: <1543347902-21170-1-git-send-email-will.deacon@arm.com>
PREEMPT_NEED_RESCHED is never used directly, so move it into the arch
code where it can potentially be implemented using either a different
bit in the preempt count or as an entirely separate entity.
Cc: Robert Love <rml@tech9.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
arch/s390/include/asm/preempt.h | 2 ++
arch/x86/include/asm/preempt.h | 3 +++
include/linux/preempt.h | 3 ---
3 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/s390/include/asm/preempt.h b/arch/s390/include/asm/preempt.h
index 23a14d187fb1..b5ea9e14c017 100644
--- a/arch/s390/include/asm/preempt.h
+++ b/arch/s390/include/asm/preempt.h
@@ -8,6 +8,8 @@
#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
+/* We use the MSB mostly because its available */
+#define PREEMPT_NEED_RESCHED 0x80000000
#define PREEMPT_ENABLED (0 + PREEMPT_NEED_RESCHED)
static inline int preempt_count(void)
diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
index 90cb2f36c042..99a7fa9ab0a3 100644
--- a/arch/x86/include/asm/preempt.h
+++ b/arch/x86/include/asm/preempt.h
@@ -8,6 +8,9 @@
DECLARE_PER_CPU(int, __preempt_count);
+/* We use the MSB mostly because its available */
+#define PREEMPT_NEED_RESCHED 0x80000000
+
/*
* We use the PREEMPT_NEED_RESCHED bit as an inverted NEED_RESCHED such
* that a decrement hitting 0 means we can and should reschedule.
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index c01813c3fbe9..dd92b1a93919 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -53,9 +53,6 @@
#define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET)
-/* We use the MSB mostly because its available */
-#define PREEMPT_NEED_RESCHED 0x80000000
-
#define PREEMPT_DISABLED (PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
/*
--
2.1.4
next prev parent reply other threads:[~2018-11-27 19:44 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-27 19:45 [PATCH 0/2] arm64: Only call into preempt_schedule() if need_resched() Will Deacon
2018-11-27 19:45 ` Will Deacon [this message]
2018-11-27 19:45 ` [PATCH 2/2] arm64: preempt: Provide our own implementation of asm/preempt.h Will Deacon
2018-11-28 15:35 ` Ard Biesheuvel
2018-11-28 16:40 ` Peter Zijlstra
2018-11-28 16:45 ` Ard Biesheuvel
2018-11-28 8:56 ` [PATCH 0/2] arm64: Only call into preempt_schedule() if need_resched() Peter Zijlstra
2018-11-28 9:01 ` Peter Zijlstra
2018-11-28 12:04 ` Will Deacon
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