From: Xin Hao <xhao@linux.alibaba.com>
To: SeongJae Park <sj@kernel.org>
Cc: akpm@linux-foundation.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH V1] mm/damon: Modify damon_rand() macro to static inline function
Date: Mon, 6 Dec 2021 20:48:18 +0800 [thread overview]
Message-ID: <08a13269-e3eb-219f-79bb-8d0153714c69@linux.alibaba.com> (raw)
In-Reply-To: <20211206124523.6259-1-sj@kernel.org>
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
prev parent reply other threads:[~2021-12-06 12:48 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
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 [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=08a13269-e3eb-219f-79bb-8d0153714c69@linux.alibaba.com \
--to=xhao@linux.alibaba.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=sj@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).