2015-07-28 04:47:40

by Minfei Huang

[permalink] [raw]
Subject: [REPOST PATCH] kexec: Remove the unnecessary conditional judgement to simplify the code logic

Transforming PFN(Page Frame Number) to struct page is never failure, so
we can simplify the code logic to do the image->control_page assignment
directly in the loop, and remove the unnecessary conditional judgement.

Signed-off-by: Minfei Huang <[email protected]>
Acked-by: Dave Young <[email protected]>
Acked-by: Vivek Goyal <[email protected]>
---
kernel/kexec.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 6f1ed75..cf82474 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -807,11 +807,10 @@ static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
/* If I don't overlap any segments I have found my hole! */
if (i == image->nr_segments) {
pages = pfn_to_page(hole_start >> PAGE_SHIFT);
+ image->control_page = hole_end;
break;
}
}
- if (pages)
- image->control_page = hole_end;

return pages;
}
--
2.4.0


2015-08-13 00:55:29

by Simon Horman

[permalink] [raw]
Subject: Re: [REPOST PATCH] kexec: Remove the unnecessary conditional judgement to simplify the code logic

On Tue, Jul 28, 2015 at 12:46:42PM +0800, Minfei Huang wrote:
> Transforming PFN(Page Frame Number) to struct page is never failure, so
> we can simplify the code logic to do the image->control_page assignment
> directly in the loop, and remove the unnecessary conditional judgement.
>
> Signed-off-by: Minfei Huang <[email protected]>
> Acked-by: Dave Young <[email protected]>
> Acked-by: Vivek Goyal <[email protected]>

Andrew, could you consider picking this up.
It seems to have been sufficiently reviewed, acked, etc...

> ---
> kernel/kexec.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/kernel/kexec.c b/kernel/kexec.c
> index 6f1ed75..cf82474 100644
> --- a/kernel/kexec.c
> +++ b/kernel/kexec.c
> @@ -807,11 +807,10 @@ static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
> /* If I don't overlap any segments I have found my hole! */
> if (i == image->nr_segments) {
> pages = pfn_to_page(hole_start >> PAGE_SHIFT);
> + image->control_page = hole_end;
> break;
> }
> }
> - if (pages)
> - image->control_page = hole_end;
>
> return pages;
> }
> --
> 2.4.0
>
>
> _______________________________________________
> kexec mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/kexec
>

2015-08-13 05:53:50

by Baoquan He

[permalink] [raw]
Subject: Re: [REPOST PATCH] kexec: Remove the unnecessary conditional judgement to simplify the code logic

On 08/13/15 at 09:55am, Simon Horman wrote:
> On Tue, Jul 28, 2015 at 12:46:42PM +0800, Minfei Huang wrote:
> > Transforming PFN(Page Frame Number) to struct page is never failure, so
> > we can simplify the code logic to do the image->control_page assignment
> > directly in the loop, and remove the unnecessary conditional judgement.
> >
> > Signed-off-by: Minfei Huang <[email protected]>
> > Acked-by: Dave Young <[email protected]>
> > Acked-by: Vivek Goyal <[email protected]>
>
> Andrew, could you consider picking this up.
> It seems to have been sufficiently reviewed, acked, etc...

I saw this has been in linux-next tree.

commit b90b6ef0f152ef42fe66ce5c9ccf2783ea84fa69
Author: Minfei Huang <[email protected]>
Date: Thu Jul 30 09:56:18 2015 +1000

kexec: remove unnecessary test in kimage_alloc_crash_control_pages()

Thanks
Baoquan

2015-08-13 07:57:39

by Simon Horman

[permalink] [raw]
Subject: Re: [REPOST PATCH] kexec: Remove the unnecessary conditional judgement to simplify the code logic

On Thu, Aug 13, 2015 at 01:53:45PM +0800, Baoquan He wrote:
> On 08/13/15 at 09:55am, Simon Horman wrote:
> > On Tue, Jul 28, 2015 at 12:46:42PM +0800, Minfei Huang wrote:
> > > Transforming PFN(Page Frame Number) to struct page is never failure, so
> > > we can simplify the code logic to do the image->control_page assignment
> > > directly in the loop, and remove the unnecessary conditional judgement.
> > >
> > > Signed-off-by: Minfei Huang <[email protected]>
> > > Acked-by: Dave Young <[email protected]>
> > > Acked-by: Vivek Goyal <[email protected]>
> >
> > Andrew, could you consider picking this up.
> > It seems to have been sufficiently reviewed, acked, etc...
>
> I saw this has been in linux-next tree.

Excellent, sorry for the noise.

> commit b90b6ef0f152ef42fe66ce5c9ccf2783ea84fa69
> Author: Minfei Huang <[email protected]>
> Date: Thu Jul 30 09:56:18 2015 +1000
>
> kexec: remove unnecessary test in kimage_alloc_crash_control_pages()
>
> Thanks
> Baoquan
>

2015-08-13 20:43:09

by Andrew Morton

[permalink] [raw]
Subject: Re: [REPOST PATCH] kexec: Remove the unnecessary conditional judgement to simplify the code logic

On Thu, 13 Aug 2015 09:55:25 +0900 Simon Horman <[email protected]> wrote:

> On Tue, Jul 28, 2015 at 12:46:42PM +0800, Minfei Huang wrote:
> > Transforming PFN(Page Frame Number) to struct page is never failure, so
> > we can simplify the code logic to do the image->control_page assignment
> > directly in the loop, and remove the unnecessary conditional judgement.
> >
> > Signed-off-by: Minfei Huang <[email protected]>
> > Acked-by: Dave Young <[email protected]>
> > Acked-by: Vivek Goyal <[email protected]>
>
> Andrew, could you consider picking this up.
> It seems to have been sufficiently reviewed, acked, etc...

I grabbed this one of July 28.
http://ozlabs.org/~akpm/mmotm/broken-out/kexec-remove-the-unnecessary-conditional-judgement-to-simplify-the-code-logic.patch