* [ltt-dev] [PATCH] uatomic: use generic-size macros for common implementation of atomic ops
@ 2011-06-09 13:57 Paolo Bonzini
2011-06-09 14:12 ` Mathieu Desnoyers
0 siblings, 1 reply; 2+ messages in thread
From: Paolo Bonzini @ 2011-06-09 13:57 UTC (permalink / raw)
The definition of _uatomic_cmpxchg is different in x86 and other architectures.
For x86 it is a 4-argument macro, for other architectures it is a 3-argument
function. This patch makes it easier to implement atomic operations
incrementally (first as a generic version and then in machine-specific code),
which aids testing and bisectability.
Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
---
Examples will come once I'll be back from my holidays. :P
urcu/uatomic_generic.h | 24 ++++++++++++++++--------
1 files changed, 16 insertions(+), 8 deletions(-)
diff --git a/urcu/uatomic_generic.h b/urcu/uatomic_generic.h
index cef58f3..337fe40 100644
--- a/urcu/uatomic_generic.h
+++ b/urcu/uatomic_generic.h
@@ -395,7 +395,8 @@ unsigned long _uatomic_add_return(void *addr, unsigned long val, int len)
oldt = uatomic_read((unsigned char *)addr);
do {
old = oldt;
- oldt = _uatomic_cmpxchg(addr, old, old + val, 1);
+ oldt = uatomic_cmpxchg((unsigned char *)addr,
+ old, old + val);
} while (oldt != old);
return old + val;
@@ -409,7 +410,8 @@ unsigned long _uatomic_add_return(void *addr, unsigned long val, int len)
oldt = uatomic_read((unsigned short *)addr);
do {
old = oldt;
- oldt = _uatomic_cmpxchg(addr, old, old + val, 2);
+ oldt = uatomic_cmpxchg((unsigned short *)addr,
+ old, old + val);
} while (oldt != old);
return old + val;
@@ -422,7 +424,8 @@ unsigned long _uatomic_add_return(void *addr, unsigned long val, int len)
oldt = uatomic_read((unsigned int *)addr);
do {
old = oldt;
- oldt = _uatomic_cmpxchg(addr, old, old + val, 4);
+ oldt = uatomic_cmpxchg((unsigned int *)addr,
+ old, old + val);
} while (oldt != old);
return old + val;
@@ -435,7 +438,8 @@ unsigned long _uatomic_add_return(void *addr, unsigned long val, int len)
oldt = uatomic_read((unsigned long *)addr);
do {
old = oldt;
- oldt = _uatomic_cmpxchg(addr, old, old + val, 8);
+ oldt = uatomic_cmpxchg((unsigned long *)addr,
+ old, old + val);
} while (oldt != old);
return old + val;
@@ -467,7 +471,8 @@ unsigned long _uatomic_exchange(void *addr, unsigned long val, int len)
oldt = uatomic_read((unsigned char *)addr);
do {
old = oldt;
- oldt = _uatomic_cmpxchg(addr, old, val, 1);
+ oldt = uatomic_cmpxchg((unsigned char *)addr,
+ old, val);
} while (oldt != old);
return old;
@@ -481,7 +486,8 @@ unsigned long _uatomic_exchange(void *addr, unsigned long val, int len)
oldt = uatomic_read((unsigned short *)addr);
do {
old = oldt;
- oldt = _uatomic_cmpxchg(addr, old, val, 2);
+ oldt = uatomic_cmpxchg((unsigned short *)addr,
+ old, val);
} while (oldt != old);
return old;
@@ -494,7 +500,8 @@ unsigned long _uatomic_exchange(void *addr, unsigned long val, int len)
oldt = uatomic_read((unsigned int *)addr);
do {
old = oldt;
- oldt = _uatomic_cmpxchg(addr, old, val, 4);
+ oldt = uatomic_cmpxchg((unsigned int *)addr,
+ old, val);
} while (oldt != old);
return old;
@@ -507,7 +514,8 @@ unsigned long _uatomic_exchange(void *addr, unsigned long val, int len)
oldt = uatomic_read((unsigned long *)addr);
do {
old = oldt;
- oldt = _uatomic_cmpxchg(addr, old, val, 8);
+ oldt = uatomic_cmpxchg((unsigned long *)addr,
+ old, val);
} while (oldt != old);
return old;
--
1.7.4.4
^ permalink raw reply [flat|nested] 2+ messages in thread* [ltt-dev] [PATCH] uatomic: use generic-size macros for common implementation of atomic ops
2011-06-09 13:57 [ltt-dev] [PATCH] uatomic: use generic-size macros for common implementation of atomic ops Paolo Bonzini
@ 2011-06-09 14:12 ` Mathieu Desnoyers
0 siblings, 0 replies; 2+ messages in thread
From: Mathieu Desnoyers @ 2011-06-09 14:12 UTC (permalink / raw)
* Paolo Bonzini (pbonzini at redhat.com) wrote:
> The definition of _uatomic_cmpxchg is different in x86 and other architectures.
> For x86 it is a 4-argument macro, for other architectures it is a 3-argument
> function. This patch makes it easier to implement atomic operations
> incrementally (first as a generic version and then in machine-specific code),
> which aids testing and bisectability.
Merged, thanks!
Mathieu
>
> Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
> ---
> Examples will come once I'll be back from my holidays. :P
>
> urcu/uatomic_generic.h | 24 ++++++++++++++++--------
> 1 files changed, 16 insertions(+), 8 deletions(-)
>
> diff --git a/urcu/uatomic_generic.h b/urcu/uatomic_generic.h
> index cef58f3..337fe40 100644
> --- a/urcu/uatomic_generic.h
> +++ b/urcu/uatomic_generic.h
> @@ -395,7 +395,8 @@ unsigned long _uatomic_add_return(void *addr, unsigned long val, int len)
> oldt = uatomic_read((unsigned char *)addr);
> do {
> old = oldt;
> - oldt = _uatomic_cmpxchg(addr, old, old + val, 1);
> + oldt = uatomic_cmpxchg((unsigned char *)addr,
> + old, old + val);
> } while (oldt != old);
>
> return old + val;
> @@ -409,7 +410,8 @@ unsigned long _uatomic_add_return(void *addr, unsigned long val, int len)
> oldt = uatomic_read((unsigned short *)addr);
> do {
> old = oldt;
> - oldt = _uatomic_cmpxchg(addr, old, old + val, 2);
> + oldt = uatomic_cmpxchg((unsigned short *)addr,
> + old, old + val);
> } while (oldt != old);
>
> return old + val;
> @@ -422,7 +424,8 @@ unsigned long _uatomic_add_return(void *addr, unsigned long val, int len)
> oldt = uatomic_read((unsigned int *)addr);
> do {
> old = oldt;
> - oldt = _uatomic_cmpxchg(addr, old, old + val, 4);
> + oldt = uatomic_cmpxchg((unsigned int *)addr,
> + old, old + val);
> } while (oldt != old);
>
> return old + val;
> @@ -435,7 +438,8 @@ unsigned long _uatomic_add_return(void *addr, unsigned long val, int len)
> oldt = uatomic_read((unsigned long *)addr);
> do {
> old = oldt;
> - oldt = _uatomic_cmpxchg(addr, old, old + val, 8);
> + oldt = uatomic_cmpxchg((unsigned long *)addr,
> + old, old + val);
> } while (oldt != old);
>
> return old + val;
> @@ -467,7 +471,8 @@ unsigned long _uatomic_exchange(void *addr, unsigned long val, int len)
> oldt = uatomic_read((unsigned char *)addr);
> do {
> old = oldt;
> - oldt = _uatomic_cmpxchg(addr, old, val, 1);
> + oldt = uatomic_cmpxchg((unsigned char *)addr,
> + old, val);
> } while (oldt != old);
>
> return old;
> @@ -481,7 +486,8 @@ unsigned long _uatomic_exchange(void *addr, unsigned long val, int len)
> oldt = uatomic_read((unsigned short *)addr);
> do {
> old = oldt;
> - oldt = _uatomic_cmpxchg(addr, old, val, 2);
> + oldt = uatomic_cmpxchg((unsigned short *)addr,
> + old, val);
> } while (oldt != old);
>
> return old;
> @@ -494,7 +500,8 @@ unsigned long _uatomic_exchange(void *addr, unsigned long val, int len)
> oldt = uatomic_read((unsigned int *)addr);
> do {
> old = oldt;
> - oldt = _uatomic_cmpxchg(addr, old, val, 4);
> + oldt = uatomic_cmpxchg((unsigned int *)addr,
> + old, val);
> } while (oldt != old);
>
> return old;
> @@ -507,7 +514,8 @@ unsigned long _uatomic_exchange(void *addr, unsigned long val, int len)
> oldt = uatomic_read((unsigned long *)addr);
> do {
> old = oldt;
> - oldt = _uatomic_cmpxchg(addr, old, val, 8);
> + oldt = uatomic_cmpxchg((unsigned long *)addr,
> + old, val);
> } while (oldt != old);
>
> return old;
> --
> 1.7.4.4
>
>
>
> _______________________________________________
> ltt-dev mailing list
> ltt-dev at lists.casi.polymtl.ca
> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
>
--
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com
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2011-06-09 14:12 ` Mathieu Desnoyers
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