* [PATCH V1] mm/damon: Modify damon_rand() macro to static inline function
@ 2021-12-06 12:41 Xin Hao
2021-12-06 12:45 ` SeongJae Park
0 siblings, 1 reply; 3+ messages in thread
From: Xin Hao @ 2021-12-06 12:41 UTC (permalink / raw)
To: sj; +Cc: xhao, akpm, linux-mm, linux-kernel
The damon_rand() func can not be implemented as a macro.
Example:
damon_rand(a++, b);
The value of 'a' will be incremented twice, This is obviously
unreasonable, So there fix it.
Fixes: b9a6ac4e4ede ("mm/damon: adaptively adjust regions")
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
---
include/linux/damon.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/include/linux/damon.h b/include/linux/damon.h
index c6df025d8704..bc9c8932b1e8 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -19,7 +19,10 @@
#define DAMOS_MAX_SCORE (99)
/* Get a random number in [l, r) */
-#define damon_rand(l, r) (l + prandom_u32_max(r - l))
+static inline unsigned long damon_rand(unsigned long l, unsigned long r)
+{
+ return l + (r - l);
+}
/**
* struct damon_addr_range - Represents an address region of [@start, @end).
--
2.31.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH V1] mm/damon: Modify damon_rand() macro to static inline function
2021-12-06 12:41 [PATCH V1] mm/damon: Modify damon_rand() macro to static inline function Xin Hao
@ 2021-12-06 12:45 ` SeongJae Park
2021-12-06 12:48 ` Xin Hao
0 siblings, 1 reply; 3+ messages in thread
From: SeongJae Park @ 2021-12-06 12:45 UTC (permalink / raw)
To: Xin Hao; +Cc: sj, akpm, linux-mm, linux-kernel
On Mon, 6 Dec 2021 20:41:29 +0800 Xin Hao <xhao@linux.alibaba.com> wrote:
> The damon_rand() func can not be implemented as a macro.
> Example:
> damon_rand(a++, b);
> The value of 'a' will be incremented twice, This is obviously
> unreasonable, So there fix it.
>
> Fixes: b9a6ac4e4ede ("mm/damon: adaptively adjust regions")
> Reported-by: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
> ---
> include/linux/damon.h | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/damon.h b/include/linux/damon.h
> index c6df025d8704..bc9c8932b1e8 100644
> --- a/include/linux/damon.h
> +++ b/include/linux/damon.h
> @@ -19,7 +19,10 @@
> #define DAMOS_MAX_SCORE (99)
>
> /* Get a random number in [l, r) */
> -#define damon_rand(l, r) (l + prandom_u32_max(r - l))
> +static inline unsigned long damon_rand(unsigned long l, unsigned long r)
> +{
> + return l + (r - l);
Seems prandom_u32_max() is missed?
Thanks,
SJ
> +}
>
> /**
> * struct damon_addr_range - Represents an address region of [@start, @end).
> --
> 2.31.0
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH V1] mm/damon: Modify damon_rand() macro to static inline function
2021-12-06 12:45 ` SeongJae Park
@ 2021-12-06 12:48 ` Xin Hao
0 siblings, 0 replies; 3+ messages in thread
From: Xin Hao @ 2021-12-06 12:48 UTC (permalink / raw)
To: SeongJae Park; +Cc: akpm, linux-mm, linux-kernel
On 12/6/21 8:45 PM, SeongJae Park wrote:
> On Mon, 6 Dec 2021 20:41:29 +0800 Xin Hao <xhao@linux.alibaba.com> wrote:
>
>> The damon_rand() func can not be implemented as a macro.
>> Example:
>> damon_rand(a++, b);
>> The value of 'a' will be incremented twice, This is obviously
>> unreasonable, So there fix it.
>>
>> Fixes: b9a6ac4e4ede ("mm/damon: adaptively adjust regions")
>> Reported-by: Andrew Morton <akpm@linux-foundation.org>
>> Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
>> ---
>> include/linux/damon.h | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/linux/damon.h b/include/linux/damon.h
>> index c6df025d8704..bc9c8932b1e8 100644
>> --- a/include/linux/damon.h
>> +++ b/include/linux/damon.h
>> @@ -19,7 +19,10 @@
>> #define DAMOS_MAX_SCORE (99)
>>
>> /* Get a random number in [l, r) */
>> -#define damon_rand(l, r) (l + prandom_u32_max(r - l))
>> +static inline unsigned long damon_rand(unsigned long l, unsigned long r)
>> +{
>> + return l + (r - l);
> Seems prandom_u32_max() is missed?
Sorry, my fault, i write a simple test case like this, but i forgot to
correct in patch, i will send a new one.
#include <stdio.h>
#define damon_rand(l, r) (l + (r - l))
static inline long damon_rand1(int l, int r)
{
return l + (r - l);
}
int main(void)
{
int a = 0;
int b = 0;
damon_rand(a++, 4);
damon_rand1(b++, 4);
printf("a is %d \n", a);
printf("b is %d \n", b);
return 0;
}
>
>
> Thanks,
> SJ
>
>> +}
>>
>> /**
>> * struct damon_addr_range - Represents an address region of [@start, @end).
>> --
>> 2.31.0
--
Best Regards!
Xin Hao
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-12-06 12:41 [PATCH V1] mm/damon: Modify damon_rand() macro to static inline function Xin Hao
2021-12-06 12:45 ` SeongJae Park
2021-12-06 12:48 ` Xin Hao
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