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From: Mathieu Desnoyers <mathieu.desnoyers@efficios•com>
To: Peter Zijlstra <peterz@infradead•org>,
	"Paul E . McKenney" <paulmck@linux•vnet.ibm.com>,
	Boqun Feng <boqun.feng@gmail•com>,
	Andy Lutomirski <luto@amacapital•net>,
	Dave Watson <davejwatson@fb•com>
Cc: linux-kernel@vger•kernel.org, linux-api@vger•kernel.org,
	Paul Turner <pjt@google•com>,
	Andrew Morton <akpm@linux-foundation•org>,
	Russell King <linux@arm•linux.org.uk>,
	Thomas Gleixner <tglx@linutronix•de>,
	Ingo Molnar <mingo@redhat•com>, "H . Peter Anvin" <hpa@zytor•com>,
	Andrew Hunter <ahh@google•com>, Andi Kleen <andi@firstfloor•org>,
	Chris Lameter <cl@linux•com>, Ben Maurer <bmaurer@fb•com>,
	Steven Rostedt <rostedt@goodmis•org>,
	Josh Triplett <josh@joshtriplett•org>,
	Linus Torvalds <torvalds@linux-foundation•org>,
	Catalin Marinas <catalin.marinas@arm•com>,
	Will Deacon <will.deacon@arm•com>,
	Michael Kerrisk <mtk.manpages@gmail•com>,
	Joel Fernandes <joelaf@google•com>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios•com>,
	Benjamin Herrenschmidt <benh@kernel•crashing.org>,
	Paul Mackerras <paulus@samba•org>,
	Michael Ellerman <mpe@ellerman•id.au>,
	linuxppc-dev@lists•ozlabs.org
Subject: [PATCH 08/14] powerpc: Wire up restartable sequences system call
Date: Mon, 30 Apr 2018 18:44:27 -0400	[thread overview]
Message-ID: <20180430224433.17407-9-mathieu.desnoyers@efficios.com> (raw)
In-Reply-To: <20180430224433.17407-1-mathieu.desnoyers@efficios.com>

From: Boqun Feng <boqun.feng@gmail•com>

Wire up the rseq system call on powerpc.

This provides an ABI improving the speed of a user-space getcpu
operation on powerpc by skipping the getcpu system call on the fast
path, as well as improving the speed of user-space operations on per-cpu
data compared to using load-reservation/store-conditional atomics.

TODO: wire up rseq_syscall() on return from system call. It is used with
CONFIG_DEBUG_RSEQ=y to ensure system calls are not issued within rseq critical
section

Signed-off-by: Boqun Feng <boqun.feng@gmail•com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios•com>
CC: Benjamin Herrenschmidt <benh@kernel•crashing.org>
CC: Paul Mackerras <paulus@samba•org>
CC: Michael Ellerman <mpe@ellerman•id.au>
CC: Peter Zijlstra <peterz@infradead•org>
CC: "Paul E. McKenney" <paulmck@linux•vnet.ibm.com>
CC: linuxppc-dev@lists•ozlabs.org
---
 arch/powerpc/include/asm/systbl.h      | 1 +
 arch/powerpc/include/asm/unistd.h      | 2 +-
 arch/powerpc/include/uapi/asm/unistd.h | 1 +
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/systbl.h b/arch/powerpc/include/asm/systbl.h
index d61f9c96d916..45d4d37495fd 100644
--- a/arch/powerpc/include/asm/systbl.h
+++ b/arch/powerpc/include/asm/systbl.h
@@ -392,3 +392,4 @@ SYSCALL(statx)
 SYSCALL(pkey_alloc)
 SYSCALL(pkey_free)
 SYSCALL(pkey_mprotect)
+SYSCALL(rseq)
diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index daf1ba97a00c..1e9708632dce 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -12,7 +12,7 @@
 #include <uapi/asm/unistd.h>
 
 
-#define NR_syscalls		387
+#define NR_syscalls		388
 
 #define __NR__exit __NR_exit
 
diff --git a/arch/powerpc/include/uapi/asm/unistd.h b/arch/powerpc/include/uapi/asm/unistd.h
index 389c36fd8299..ac5ba55066dd 100644
--- a/arch/powerpc/include/uapi/asm/unistd.h
+++ b/arch/powerpc/include/uapi/asm/unistd.h
@@ -398,5 +398,6 @@
 #define __NR_pkey_alloc		384
 #define __NR_pkey_free		385
 #define __NR_pkey_mprotect	386
+#define __NR_rseq		387
 
 #endif /* _UAPI_ASM_POWERPC_UNISTD_H_ */
-- 
2.11.0

      parent reply	other threads:[~2018-04-30 22:44 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20180430224433.17407-1-mathieu.desnoyers@efficios.com>
2018-04-30 22:44 ` [PATCH 07/14] powerpc: Add support for restartable sequences Mathieu Desnoyers
2018-05-16 16:18   ` Peter Zijlstra
2018-05-16 20:13     ` Mathieu Desnoyers
2018-05-17  1:19       ` Boqun Feng
2018-05-17  7:43         ` Peter Zijlstra
2018-05-17 15:28         ` Mathieu Desnoyers
2018-05-17 23:50           ` Boqun Feng
2018-05-18 18:17             ` Mathieu Desnoyers
2018-05-20 14:08               ` Boqun Feng
2018-05-23 20:14                 ` Mathieu Desnoyers
2018-05-23 20:46                   ` Paul E. McKenney
2018-05-23 21:29                   ` Mathieu Desnoyers
2018-05-24  1:03                     ` Michael Ellerman
2018-05-28  7:00                       ` Mathieu Desnoyers
2018-05-18 12:38           ` Michael Ellerman
2018-04-30 22:44 ` Mathieu Desnoyers [this message]

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