All of lore.kernel.org
 help / color / mirror / Atom feed
From: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Joe Perches <joe@perches.com>, Simon Horman <horms@verge.net.au>,
	"kexec@lists.infradead.org" <kexec@lists.infradead.org>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 2/2] kexec: Use min_t to simplify logic
Date: Tue, 26 Feb 2013 16:55:57 +0800	[thread overview]
Message-ID: <512C789D.1090404@cn.fujitsu.com> (raw)
In-Reply-To: <20130226005328.e2d31a97.akpm@linux-foundation.org>

于 2013年02月26日 16:53, Andrew Morton 写道:
> On Tue, 26 Feb 2013 16:49:02 +0800 Zhang Yanfei <zhangyanfei@cn.fujitsu.com> wrote:
> 
>>>> diff --git a/kernel/kexec.c b/kernel/kexec.c
>>> []
>>>> @@ -822,13 +822,9 @@ static int kimage_load_normal_segment(struct kimage *image,
>>> []
>>>> +		mchunk = min_t(size_t, mbytes,
>>>> +			       (size_t)(PAGE_SIZE - (maddr & ~PAGE_MASK)));
>>>
>>> #define min_t(type, x, y) ({			\
>>> 	type __min1 = (x);			\
>>> 	type __min2 = (y);			\
>>> 	__min1 < __min2 ? __min1: __min2; })
>>>
>>>
>>>
>>
>> Hmm, from the definition, the cast is redundant.
>>
>> Maybe I misunderstood what Andrew meant in the mail related to v2:
>>
>> "The types of PAGE_SIZE and PAGE_MASK are vague - iirc they once had
>> different types on different architectures, so some form of casting is
>> unavoidable here."
>>
>> Andrew, could you please explain the casting you meant above?
> 
> I mean that a cast (or min_t, which is a cast) will be needed. 
> The code you have here casts the same thing two times, which isn't
> necessary.
> 
> 

Thanks.

Should I resend the patch again? After removing this redundant cast,
it is the same with v2.

Zhang

_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

WARNING: multiple messages have this Message-ID (diff)
From: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Joe Perches <joe@perches.com>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Simon Horman <horms@verge.net.au>,
	"kexec@lists.infradead.org" <kexec@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 2/2] kexec: Use min_t to simplify logic
Date: Tue, 26 Feb 2013 16:55:57 +0800	[thread overview]
Message-ID: <512C789D.1090404@cn.fujitsu.com> (raw)
In-Reply-To: <20130226005328.e2d31a97.akpm@linux-foundation.org>

于 2013年02月26日 16:53, Andrew Morton 写道:
> On Tue, 26 Feb 2013 16:49:02 +0800 Zhang Yanfei <zhangyanfei@cn.fujitsu.com> wrote:
> 
>>>> diff --git a/kernel/kexec.c b/kernel/kexec.c
>>> []
>>>> @@ -822,13 +822,9 @@ static int kimage_load_normal_segment(struct kimage *image,
>>> []
>>>> +		mchunk = min_t(size_t, mbytes,
>>>> +			       (size_t)(PAGE_SIZE - (maddr & ~PAGE_MASK)));
>>>
>>> #define min_t(type, x, y) ({			\
>>> 	type __min1 = (x);			\
>>> 	type __min2 = (y);			\
>>> 	__min1 < __min2 ? __min1: __min2; })
>>>
>>>
>>>
>>
>> Hmm, from the definition, the cast is redundant.
>>
>> Maybe I misunderstood what Andrew meant in the mail related to v2:
>>
>> "The types of PAGE_SIZE and PAGE_MASK are vague - iirc they once had
>> different types on different architectures, so some form of casting is
>> unavoidable here."
>>
>> Andrew, could you please explain the casting you meant above?
> 
> I mean that a cast (or min_t, which is a cast) will be needed. 
> The code you have here casts the same thing two times, which isn't
> necessary.
> 
> 

Thanks.

Should I resend the patch again? After removing this redundant cast,
it is the same with v2.

Zhang

  reply	other threads:[~2013-02-26  8:57 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-26  5:15 [PATCH v3 1/2] kexec: fix wrong types of some local variables Zhang Yanfei
2013-02-26  5:15 ` Zhang Yanfei
2013-02-26  5:30 ` [PATCH v3 2/2] kexec: Use min_t to simplify logic Zhang Yanfei
2013-02-26  5:30   ` Zhang Yanfei
2013-02-26  8:38   ` Joe Perches
2013-02-26  8:38     ` Joe Perches
2013-02-26  8:49     ` Zhang Yanfei
2013-02-26  8:49       ` Zhang Yanfei
2013-02-26  8:53       ` Andrew Morton
2013-02-26  8:53         ` Andrew Morton
2013-02-26  8:55         ` Zhang Yanfei [this message]
2013-02-26  8:55           ` Zhang Yanfei
2013-02-27 22:31           ` Andrew Morton
2013-02-27 22:31             ` Andrew Morton
2013-03-01  1:31 ` [PATCH v3 1/2] kexec: fix wrong types of some local variables Simon Horman
2013-03-01  1:31   ` Simon Horman

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=512C789D.1090404@cn.fujitsu.com \
    --to=zhangyanfei@cn.fujitsu.com \
    --cc=akpm@linux-foundation.org \
    --cc=ebiederm@xmission.com \
    --cc=horms@verge.net.au \
    --cc=joe@perches.com \
    --cc=kexec@lists.infradead.org \
    --cc=linux-kernel@vger.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.