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From: anton.ivanov@cambridgegreys.com
To: linux-um@lists.infradead.org
Cc: richard@nod.at, Anton Ivanov <anton.ivanov@cambridgegreys.com>
Subject: [PATCH v4 3/7] um: "borrow" atomics from x86 architecture
Date: Fri, 11 Dec 2020 17:45:55 +0000	[thread overview]
Message-ID: <20201211174559.26010-4-anton.ivanov@cambridgegreys.com> (raw)
In-Reply-To: <20201211174559.26010-1-anton.ivanov@cambridgegreys.com>

From: Anton Ivanov <anton.ivanov@cambridgegreys.com>

This moves UML on 64 bit from generic atomics to their x86
equivalents.

Generic atomics bracket most operations by interrupts off/interrupts
on. This is quite expensive on UML - it translates to changing
the signal mask and rerunning the signal loop every time.

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
---
 arch/um/include/asm/atomic-x86.h  | 1 +
 arch/um/include/asm/atomic.h      | 7 +++++++
 arch/um/include/asm/atomic64_64.h | 1 +
 3 files changed, 9 insertions(+)
 create mode 120000 arch/um/include/asm/atomic-x86.h
 create mode 100644 arch/um/include/asm/atomic.h
 create mode 120000 arch/um/include/asm/atomic64_64.h

diff --git a/arch/um/include/asm/atomic-x86.h b/arch/um/include/asm/atomic-x86.h
new file mode 120000
index 000000000000..e71a389e112d
--- /dev/null
+++ b/arch/um/include/asm/atomic-x86.h
@@ -0,0 +1 @@
+../../../x86/include/asm/atomic.h
\ No newline at end of file
diff --git a/arch/um/include/asm/atomic.h b/arch/um/include/asm/atomic.h
new file mode 100644
index 000000000000..6ff22c587c10
--- /dev/null
+++ b/arch/um/include/asm/atomic.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_ATOMIC_XOR_H
+#define _ASM_ATOMIC_XOR_H
+
+#include <asm/atomic-x86.h>
+
+#endif
diff --git a/arch/um/include/asm/atomic64_64.h b/arch/um/include/asm/atomic64_64.h
new file mode 120000
index 000000000000..f817a1478603
--- /dev/null
+++ b/arch/um/include/asm/atomic64_64.h
@@ -0,0 +1 @@
+../../../x86/include/asm/atomic64_64.h
\ No newline at end of file
-- 
2.20.1


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  parent reply	other threads:[~2020-12-11 17:46 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-11 17:45 Amended and retested for 32 bit "borrow ops" series anton.ivanov
2020-12-11 17:45 ` [PATCH v4 1/7] um: allow the use of glibc functions instead of builtins anton.ivanov
2020-12-11 20:03   ` Johannes Berg
2020-12-11 17:45 ` [PATCH v4 2/7] um: enable the use of optimized xor routines in UML anton.ivanov
2020-12-11 20:07   ` Johannes Berg
2020-12-11 21:57     ` Anton Ivanov
2020-12-11 22:00       ` Johannes Berg
2020-12-11 22:40         ` Anton Ivanov
2020-12-14  9:07         ` Anton Ivanov
2020-12-14  9:12           ` Johannes Berg
2020-12-14  9:36             ` Anton Ivanov
2020-12-11 17:45 ` anton.ivanov [this message]
2020-12-11 20:08   ` [PATCH v4 3/7] um: "borrow" atomics from x86 architecture Johannes Berg
2020-12-11 21:31     ` Anton Ivanov
2020-12-11 17:45 ` [PATCH v4 4/7] um: add a UML specific futex implementation anton.ivanov
2020-12-11 20:10   ` Johannes Berg
2020-12-11 17:45 ` [PATCH v4 5/7] um: "borrow" cmpxchg from x86 tree in UML anton.ivanov
2020-12-11 17:45 ` [PATCH v4 6/7] um: swithch futex ops to cmpxchg anton.ivanov
2020-12-11 20:12   ` Johannes Berg
2020-12-11 21:33     ` Anton Ivanov
2020-12-11 17:45 ` [PATCH v4 7/7] um: borrow bitops from the x86 tree anton.ivanov

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