* [PATCH] x86: introduce and use percpu_inc()
@ 2010-04-21 14:21 Jan Beulich
2010-04-21 17:56 ` H. Peter Anvin
2010-04-29 0:54 ` [tip:x86/asm] x86, asm: Introduce " tip-bot for Jan Beulich
0 siblings, 2 replies; 3+ messages in thread
From: Jan Beulich @ 2010-04-21 14:21 UTC (permalink / raw)
To: mingo, tglx, hpa; +Cc: linux-kernel
... generating slightly smaller code.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
---
arch/x86/include/asm/hardirq.h | 2 +-
arch/x86/include/asm/percpu.h | 24 ++++++++++++++++++++++++
arch/x86/kernel/cpu/mcheck/mce.c | 4 ++--
3 files changed, 27 insertions(+), 3 deletions(-)
--- linux-2.6.34-rc5/arch/x86/include/asm/hardirq.h 2010-02-24 19:52:17.000000000 +0100
+++ 2.6.34-rc5-x86-inc-percpu/arch/x86/include/asm/hardirq.h 2010-04-15 11:58:06.000000000 +0200
@@ -35,7 +35,7 @@ DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpust
#define __ARCH_IRQ_STAT
-#define inc_irq_stat(member) percpu_add(irq_stat.member, 1)
+#define inc_irq_stat(member) percpu_inc(irq_stat.member)
#define local_softirq_pending() percpu_read(irq_stat.__softirq_pending)
--- linux-2.6.34-rc5/arch/x86/include/asm/percpu.h 2010-04-20 16:07:41.000000000 +0200
+++ 2.6.34-rc5-x86-inc-percpu/arch/x86/include/asm/percpu.h 2010-04-15 11:58:06.000000000 +0200
@@ -190,6 +190,29 @@ do { \
pfo_ret__; \
})
+#define percpu_unary_op(op, var) \
+({ \
+ switch (sizeof(var)) { \
+ case 1: \
+ asm(op "b "__percpu_arg(0) \
+ : "+m" (var)); \
+ break; \
+ case 2: \
+ asm(op "w "__percpu_arg(0) \
+ : "+m" (var)); \
+ break; \
+ case 4: \
+ asm(op "l "__percpu_arg(0) \
+ : "+m" (var)); \
+ break; \
+ case 8: \
+ asm(op "q "__percpu_arg(0) \
+ : "+m" (var)); \
+ break; \
+ default: __bad_percpu_size(); \
+ } \
+})
+
/*
* percpu_read() makes gcc load the percpu variable every time it is
* accessed while percpu_read_stable() allows the value to be cached.
@@ -207,6 +230,7 @@ do { \
#define percpu_and(var, val) percpu_to_op("and", var, val)
#define percpu_or(var, val) percpu_to_op("or", var, val)
#define percpu_xor(var, val) percpu_to_op("xor", var, val)
+#define percpu_inc(var) percpu_unary_op("inc", var)
#define __this_cpu_read_1(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define __this_cpu_read_2(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
--- linux-2.6.34-rc5/arch/x86/kernel/cpu/mcheck/mce.c 2010-04-20 16:07:42.000000000 +0200
+++ 2.6.34-rc5-x86-inc-percpu/arch/x86/kernel/cpu/mcheck/mce.c 2010-04-15 11:58:06.000000000 +0200
@@ -539,7 +539,7 @@ void machine_check_poll(enum mcp_flags f
struct mce m;
int i;
- __get_cpu_var(mce_poll_count)++;
+ percpu_inc(mce_poll_count);
mce_setup(&m);
@@ -934,7 +934,7 @@ void do_machine_check(struct pt_regs *re
atomic_inc(&mce_entry);
- __get_cpu_var(mce_exception_count)++;
+ percpu_inc(mce_exception_count);
if (notify_die(DIE_NMI, "machine check", regs, error_code,
18, SIGKILL) == NOTIFY_STOP)
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] x86: introduce and use percpu_inc()
2010-04-21 14:21 [PATCH] x86: introduce and use percpu_inc() Jan Beulich
@ 2010-04-21 17:56 ` H. Peter Anvin
2010-04-29 0:54 ` [tip:x86/asm] x86, asm: Introduce " tip-bot for Jan Beulich
1 sibling, 0 replies; 3+ messages in thread
From: H. Peter Anvin @ 2010-04-21 17:56 UTC (permalink / raw)
To: Jan Beulich; +Cc: mingo, tglx, linux-kernel
On 04/21/2010 07:21 AM, Jan Beulich wrote:
> ... generating slightly smaller code.
>
> Signed-off-by: Jan Beulich <jbeulich@novell.com>
How much smaller? Keep in mind that although INC is smaller than ADD,
the former has flag dependencies that the latter doesn't...
-hpa
^ permalink raw reply [flat|nested] 3+ messages in thread
* [tip:x86/asm] x86, asm: Introduce and use percpu_inc()
2010-04-21 14:21 [PATCH] x86: introduce and use percpu_inc() Jan Beulich
2010-04-21 17:56 ` H. Peter Anvin
@ 2010-04-29 0:54 ` tip-bot for Jan Beulich
1 sibling, 0 replies; 3+ messages in thread
From: tip-bot for Jan Beulich @ 2010-04-29 0:54 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, jbeulich, JBeulich, tglx
Commit-ID: 402af0d7c692ddcfa2333e93d3f275ebd0487926
Gitweb: http://git.kernel.org/tip/402af0d7c692ddcfa2333e93d3f275ebd0487926
Author: Jan Beulich <JBeulich@novell.com>
AuthorDate: Wed, 21 Apr 2010 15:21:51 +0100
Committer: H. Peter Anvin <hpa@zytor.com>
CommitDate: Wed, 28 Apr 2010 16:58:49 -0700
x86, asm: Introduce and use percpu_inc()
... generating slightly smaller code.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <4BCF261F020000780003B33C@vpn.id2.novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
arch/x86/include/asm/hardirq.h | 2 +-
arch/x86/include/asm/percpu.h | 24 ++++++++++++++++++++++++
arch/x86/kernel/cpu/mcheck/mce.c | 4 ++--
3 files changed, 27 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index 0f85764..aeab29a 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -35,7 +35,7 @@ DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
#define __ARCH_IRQ_STAT
-#define inc_irq_stat(member) percpu_add(irq_stat.member, 1)
+#define inc_irq_stat(member) percpu_inc(irq_stat.member)
#define local_softirq_pending() percpu_read(irq_stat.__softirq_pending)
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index 66a272d..0ec6d12 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -190,6 +190,29 @@ do { \
pfo_ret__; \
})
+#define percpu_unary_op(op, var) \
+({ \
+ switch (sizeof(var)) { \
+ case 1: \
+ asm(op "b "__percpu_arg(0) \
+ : "+m" (var)); \
+ break; \
+ case 2: \
+ asm(op "w "__percpu_arg(0) \
+ : "+m" (var)); \
+ break; \
+ case 4: \
+ asm(op "l "__percpu_arg(0) \
+ : "+m" (var)); \
+ break; \
+ case 8: \
+ asm(op "q "__percpu_arg(0) \
+ : "+m" (var)); \
+ break; \
+ default: __bad_percpu_size(); \
+ } \
+})
+
/*
* percpu_read() makes gcc load the percpu variable every time it is
* accessed while percpu_read_stable() allows the value to be cached.
@@ -207,6 +230,7 @@ do { \
#define percpu_and(var, val) percpu_to_op("and", var, val)
#define percpu_or(var, val) percpu_to_op("or", var, val)
#define percpu_xor(var, val) percpu_to_op("xor", var, val)
+#define percpu_inc(var) percpu_unary_op("inc", var)
#define __this_cpu_read_1(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define __this_cpu_read_2(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 8a6f0af..7a355dd 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -539,7 +539,7 @@ void machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
struct mce m;
int i;
- __get_cpu_var(mce_poll_count)++;
+ percpu_inc(mce_poll_count);
mce_setup(&m);
@@ -934,7 +934,7 @@ void do_machine_check(struct pt_regs *regs, long error_code)
atomic_inc(&mce_entry);
- __get_cpu_var(mce_exception_count)++;
+ percpu_inc(mce_exception_count);
if (notify_die(DIE_NMI, "machine check", regs, error_code,
18, SIGKILL) == NOTIFY_STOP)
^ permalink raw reply [flat|nested] 3+ messages in thread
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2010-04-21 14:21 [PATCH] x86: introduce and use percpu_inc() Jan Beulich
2010-04-21 17:56 ` H. Peter Anvin
2010-04-29 0:54 ` [tip:x86/asm] x86, asm: Introduce " tip-bot for Jan Beulich
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