[PATCH 1/2] take the segment adding out of locate_mem_hole functions

[PATCH 1/2] take the segment adding out of locate_mem_hole functions

[Baoquan He]

In locate_mem_hole functions, a memory hole is located and added as
kexec_segment. But from the name of locate_mem_hole, it should only
take responsibility of searching a available memory hole to contain
data of a specified size.

So in this patch add a new field 'mem' into kexec_buf, then take that
kexec segment adding code out of locate_mem_hole_top_down and
locate_mem_hole_bottom_up. This make clear of the functionality of
locate_mem_hole just like it declars to do. And by this
locate_mem_hole_callback chould be used later if anyone want to locate
a memory hole for other use.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
 include/linux/kexec.h | 1 +
 kernel/kexec.c        | 9 +++++----
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 4b2a0e1..9d957b7 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -178,6 +178,7 @@ struct kexec_buf {
 	struct kimage *image;
 	char *buffer;
 	unsigned long bufsz;
+	unsigned long mem;
 	unsigned long memsz;
 	unsigned long buf_align;
 	unsigned long buf_min;
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 0b49a0a..586444e 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -2054,8 +2054,7 @@ static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
 	} while (1);
 
 	/* If we are here, we found a suitable memory range */
-	__kexec_add_segment(image, kbuf->buffer, kbuf->bufsz, temp_start,
-			    kbuf->memsz);
+	kbuf->mem = temp_start;
 
 	/* Success, stop navigating through remaining System RAM ranges */
 	return 1;
@@ -2089,8 +2088,7 @@ static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
 	} while (1);
 
 	/* If we are here, we found a suitable memory range */
-	__kexec_add_segment(image, kbuf->buffer, kbuf->bufsz, temp_start,
-			    kbuf->memsz);
+	kbuf->mem = temp_start;
 
 	/* Success, stop navigating through remaining System RAM ranges */
 	return 1;
@@ -2176,6 +2174,9 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
 		return -EADDRNOTAVAIL;
 	}
 
+	__kexec_add_segment(image, kbuf->buffer, kbuf->bufsz, kbuf->mem,
+			    kbuf->memsz);
+
 	/* Found a suitable memory range */
 	ksegment = &image->segment[image->nr_segments - 1];
 	*load_addr = ksegment->mem;
-- 
1.8.5.3

[PATCH 2/2] check if crashk_res_low exists when exclude it from crash mem ranges

[Baoquan He]

Add a check if crashk_res_low exists just like GART region does. If
crashk_res_low doesn't exist, calling exclude_mem_range is unnecessary.

Meanwhile, since crashk_res_low has been initialized at definition, it's
safe just use "if (crashk_low_res.end)" to check if it's exist. And this
can make it consistent with other places of check.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
 arch/x86/kernel/crash.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 0553a34..c9e83f9 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -238,7 +238,7 @@ static void fill_up_crash_elf_data(struct crash_elf_data *ced,
 	ced->max_nr_ranges++;
 
 	/* If crashk_low_res is not 0, another range split possible */
-	if (crashk_low_res.end != 0)
+	if (crashk_low_res.end)
 		ced->max_nr_ranges++;
 }
 
@@ -336,9 +336,11 @@ static int elf_header_exclude_ranges(struct crash_elf_data *ced,
 	if (ret)
 		return ret;
 
-	ret = exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
-	if (ret)
-		return ret;
+	if (crashk_low_res.end) {
+		ret = exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
+		if (ret)
+			return ret;
+	}
 
 	/* Exclude GART region */
 	if (ced->gart_end) {
-- 
1.8.5.3

Re: [PATCH 2/2] check if crashk_res_low exists when exclude it from crash mem ranges

[Vivek Goyal]

On Tue, Aug 12, 2014 at 01:29:28PM +0800, Baoquan He wrote:
> Add a check if crashk_res_low exists just like GART region does. If
> crashk_res_low doesn't exist, calling exclude_mem_range is unnecessary.
> 
> Meanwhile, since crashk_res_low has been initialized at definition, it's
> safe just use "if (crashk_low_res.end)" to check if it's exist. And this
> can make it consistent with other places of check.
> 
> Signed-off-by: Baoquan He <bhe@redhat.com>

This patch looks good.

Acked-by: Vivek Goyal <vgoyal@redhat.com>

Vivek

> ---
>  arch/x86/kernel/crash.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> index 0553a34..c9e83f9 100644
> --- a/arch/x86/kernel/crash.c
> +++ b/arch/x86/kernel/crash.c
> @@ -238,7 +238,7 @@ static void fill_up_crash_elf_data(struct crash_elf_data *ced,
>  	ced->max_nr_ranges++;
>  
>  	/* If crashk_low_res is not 0, another range split possible */
> -	if (crashk_low_res.end != 0)
> +	if (crashk_low_res.end)
>  		ced->max_nr_ranges++;
>  }
>  
> @@ -336,9 +336,11 @@ static int elf_header_exclude_ranges(struct crash_elf_data *ced,
>  	if (ret)
>  		return ret;
>  
> -	ret = exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
> -	if (ret)
> -		return ret;
> +	if (crashk_low_res.end) {
> +		ret = exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
> +		if (ret)
> +			return ret;
> +	}
>  
>  	/* Exclude GART region */
>  	if (ced->gart_end) {
> -- 
> 1.8.5.3

Re: [PATCH 1/2] take the segment adding out of locate_mem_hole functions

[Vivek Goyal]

On Tue, Aug 12, 2014 at 01:29:27PM +0800, Baoquan He wrote:
> In locate_mem_hole functions, a memory hole is located and added as
> kexec_segment. But from the name of locate_mem_hole, it should only
> take responsibility of searching a available memory hole to contain
> data of a specified size.
> 
> So in this patch add a new field 'mem' into kexec_buf, then take that
> kexec segment adding code out of locate_mem_hole_top_down and
> locate_mem_hole_bottom_up. This make clear of the functionality of
> locate_mem_hole just like it declars to do. And by this
> locate_mem_hole_callback chould be used later if anyone want to locate
> a memory hole for other use.
> 
> Signed-off-by: Baoquan He <bhe@redhat.com>
> ---
>  include/linux/kexec.h | 1 +
>  kernel/kexec.c        | 9 +++++----
>  2 files changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index 4b2a0e1..9d957b7 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -178,6 +178,7 @@ struct kexec_buf {
>  	struct kimage *image;
>  	char *buffer;
>  	unsigned long bufsz;
> +	unsigned long mem;
>  	unsigned long memsz;
>  	unsigned long buf_align;
>  	unsigned long buf_min;
> diff --git a/kernel/kexec.c b/kernel/kexec.c
> index 0b49a0a..586444e 100644
> --- a/kernel/kexec.c
> +++ b/kernel/kexec.c
> @@ -2054,8 +2054,7 @@ static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
>  	} while (1);
>  
>  	/* If we are here, we found a suitable memory range */
> -	__kexec_add_segment(image, kbuf->buffer, kbuf->bufsz, temp_start, > -			    kbuf->memsz);
> +	kbuf->mem = temp_start;
>  
>  	/* Success, stop navigating through remaining System RAM ranges */
>  	return 1;
> @@ -2089,8 +2088,7 @@ static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
>  	} while (1);
>  
>  	/* If we are here, we found a suitable memory range */
> -	__kexec_add_segment(image, kbuf->buffer, kbuf->bufsz, temp_start,
> -			    kbuf->memsz);
> +	kbuf->mem = temp_start;
>  
>  	/* Success, stop navigating through remaining System RAM ranges */
>  	return 1;
> @@ -2176,6 +2174,9 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
>  		return -EADDRNOTAVAIL;
>  	}
>  
> +	__kexec_add_segment(image, kbuf->buffer, kbuf->bufsz, kbuf->mem,
> +			    kbuf->memsz);
> +

I think let us open code this function then. That way we have to
retreive ksegment pointer once and it is easy to read.

  	/* Found a suitable memory range */
	ksegment = &image->segment[image->nr_segments];
        ksegment->kbuf = kbuf->buffer;
        ksegment->bufsz = kbuf->bufsz;
        ksegment->mem = kbuf->mem;
        ksegment->memsz = kbuf->memsz;
        image->nr_segments++;
	*load_addr = ksegment->mem;

>  	/* Found a suitable memory range */
>  	ksegment = &image->segment[image->nr_segments - 1];
>  	*load_addr = ksegment->mem;

If possible, can you hold on to your cleanup patches for a bit. I want
to post some patches to introduce a config option for new syscall and
they will need to go in sooner. You can rebase your patches on top of
that.

Thanks
Vivek

Re: [PATCH 1/2] take the segment adding out of locate_mem_hole functions

[Baoquan He]

On 08/12/14 at 05:00pm, Vivek Goyal wrote:
> On Tue, Aug 12, 2014 at 01:29:27PM +0800, Baoquan He wrote:
> > In locate_mem_hole functions, a memory hole is located and added as
> > kexec_segment. But from the name of locate_mem_hole, it should only
> > take responsibility of searching a available memory hole to contain
> > data of a specified size.
> > 
> > So in this patch add a new field 'mem' into kexec_buf, then take that
> > kexec segment adding code out of locate_mem_hole_top_down and
> > locate_mem_hole_bottom_up. This make clear of the functionality of
> > locate_mem_hole just like it declars to do. And by this
> > locate_mem_hole_callback chould be used later if anyone want to locate
> > a memory hole for other use.
> > 
> > Signed-off-by: Baoquan He <bhe@redhat.com>
> > ---
> >  include/linux/kexec.h | 1 +
> >  kernel/kexec.c        | 9 +++++----
> >  2 files changed, 6 insertions(+), 4 deletions(-)
> > 
> > diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> > index 4b2a0e1..9d957b7 100644
> > --- a/include/linux/kexec.h
> > +++ b/include/linux/kexec.h
> > @@ -178,6 +178,7 @@ struct kexec_buf {
> >  	struct kimage *image;
> >  	char *buffer;
> >  	unsigned long bufsz;
> > +	unsigned long mem;
> >  	unsigned long memsz;
> >  	unsigned long buf_align;
> >  	unsigned long buf_min;
> > diff --git a/kernel/kexec.c b/kernel/kexec.c
> > index 0b49a0a..586444e 100644
> > --- a/kernel/kexec.c
> > +++ b/kernel/kexec.c
> > @@ -2054,8 +2054,7 @@ static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
> >  	} while (1);
> >  
> >  	/* If we are here, we found a suitable memory range */
> > -	__kexec_add_segment(image, kbuf->buffer, kbuf->bufsz, temp_start, > -			    kbuf->memsz);
> > +	kbuf->mem = temp_start;
> >  
> >  	/* Success, stop navigating through remaining System RAM ranges */
> >  	return 1;
> > @@ -2089,8 +2088,7 @@ static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
> >  	} while (1);
> >  
> >  	/* If we are here, we found a suitable memory range */
> > -	__kexec_add_segment(image, kbuf->buffer, kbuf->bufsz, temp_start,
> > -			    kbuf->memsz);
> > +	kbuf->mem = temp_start;
> >  
> >  	/* Success, stop navigating through remaining System RAM ranges */
> >  	return 1;
> > @@ -2176,6 +2174,9 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
> >  		return -EADDRNOTAVAIL;
> >  	}
> >  
> > +	__kexec_add_segment(image, kbuf->buffer, kbuf->bufsz, kbuf->mem,
> > +			    kbuf->memsz);
> > +
> 
> I think let us open code this function then. That way we have to
> retreive ksegment pointer once and it is easy to read.
> 
>   	/* Found a suitable memory range */
> 	ksegment = &image->segment[image->nr_segments];
>         ksegment->kbuf = kbuf->buffer;
>         ksegment->bufsz = kbuf->bufsz;
>         ksegment->mem = kbuf->mem;
>         ksegment->memsz = kbuf->memsz;
>         image->nr_segments++;
> 	*load_addr = ksegment->mem;

Yes, it's good to me.

> 
> >  	/* Found a suitable memory range */
> >  	ksegment = &image->segment[image->nr_segments - 1];
> >  	*load_addr = ksegment->mem;
> 
> If possible, can you hold on to your cleanup patches for a bit. I want
> to post some patches to introduce a config option for new syscall and
> they will need to go in sooner. You can rebase your patches on top of
> that.

Sure, I can wait. Thanks for telling.

> 
> Thanks
> Vivek