Re: [PATCH 4/8] struct page: add field for vm_struct

[J Freyensee]

On 3/15/18 2:38 AM, Igor Stoppa wrote:

On 14/03/18 19:43, J Freyensee wrote:

On 3/13/18 3:00 PM, Matthew Wilcox wrote:

[...]


Signed-off-by: Igor Stoppa 

Reviewed-by: Matthew Wilcox 

Igor, do you mind sticking these tags on the files that have spent some
time reviewing a revision of your patchset (like the Reviewed-by: tags I
provided last revision?)

Apologies, that was not intentional, I forgot it.
I will do it, although most of the files will now change so much that I
am not sure what will survive, beside this patch, in the form that you
reviewed.

I suppose the Review-by tag drops, if the patch changes.


That's true, if so much of the patch changes it basically looks like 
something different, the Reviewed-by: would drop.


Jay



--
igor

Re: [PATCH 4/8] struct page: add field for vm_struct

[J Freyensee]

On 3/15/18 2:38 AM, Igor Stoppa wrote:

On 14/03/18 19:43, J Freyensee wrote:

On 3/13/18 3:00 PM, Matthew Wilcox wrote:

[...]


Signed-off-by: Igor Stoppa 

Reviewed-by: Matthew Wilcox 

Igor, do you mind sticking these tags on the files that have spent some
time reviewing a revision of your patchset (like the Reviewed-by: tags I
provided last revision?)

Apologies, that was not intentional, I forgot it.
I will do it, although most of the files will now change so much that I
am not sure what will survive, beside this patch, in the form that you
reviewed.

I suppose the Review-by tag drops, if the patch changes.


That's true, if so much of the patch changes it basically looks like 
something different, the Reviewed-by: would drop.


Jay



--
igor

Re: [PATCH 4/8] struct page: add field for vm_struct

[Igor Stoppa]

On 14/03/18 19:43, J Freyensee wrote:
> On 3/13/18 3:00 PM, Matthew Wilcox wrote:

[...]

>>> Signed-off-by: Igor Stoppa 
>> Reviewed-by: Matthew Wilcox 
> 
> Igor, do you mind sticking these tags on the files that have spent some 
> time reviewing a revision of your patchset (like the Reviewed-by: tags I 
> provided last revision?)

Apologies, that was not intentional, I forgot it.
I will do it, although most of the files will now change so much that I
am not sure what will survive, beside this patch, in the form that you
reviewed.

I suppose the Review-by tag drops, if the patch changes.

--
igor

Re: [PATCH 4/8] struct page: add field for vm_struct

[Igor Stoppa]

On 14/03/18 19:43, J Freyensee wrote:
> On 3/13/18 3:00 PM, Matthew Wilcox wrote:

[...]

>>> Signed-off-by: Igor Stoppa 
>> Reviewed-by: Matthew Wilcox 
> 
> Igor, do you mind sticking these tags on the files that have spent some 
> time reviewing a revision of your patchset (like the Reviewed-by: tags I 
> provided last revision?)

Apologies, that was not intentional, I forgot it.
I will do it, although most of the files will now change so much that I
am not sure what will survive, beside this patch, in the form that you
reviewed.

I suppose the Review-by tag drops, if the patch changes.

--
igor

Re: [PATCH 4/8] struct page: add field for vm_struct

[J Freyensee]

On 3/13/18 3:00 PM, Matthew Wilcox wrote:

On Tue, Mar 13, 2018 at 11:45:50PM +0200, Igor Stoppa wrote:

When a page is used for virtual memory, it is often necessary to obtain
a handler to the corresponding vm_struct, which refers to the virtually
continuous area generated when invoking vmalloc.

The struct page has a "mapping" field, which can be re-used, to store a
pointer to the parent area.

This will avoid more expensive searches, later on.

Signed-off-by: Igor Stoppa 

Reviewed-by: Matthew Wilcox 


Igor, do you mind sticking these tags on the files that have spent some 
time reviewing a revision of your patchset (like the Reviewed-by: tags I 
provided last revision?)


Thanks,
Jay

Re: [PATCH 4/8] struct page: add field for vm_struct

[J Freyensee]

On 3/13/18 3:00 PM, Matthew Wilcox wrote:

On Tue, Mar 13, 2018 at 11:45:50PM +0200, Igor Stoppa wrote:

When a page is used for virtual memory, it is often necessary to obtain
a handler to the corresponding vm_struct, which refers to the virtually
continuous area generated when invoking vmalloc.

The struct page has a "mapping" field, which can be re-used, to store a
pointer to the parent area.

This will avoid more expensive searches, later on.

Signed-off-by: Igor Stoppa 

Reviewed-by: Matthew Wilcox 


Igor, do you mind sticking these tags on the files that have spent some 
time reviewing a revision of your patchset (like the Reviewed-by: tags I 
provided last revision?)


Thanks,
Jay

Re: [PATCH 4/8] struct page: add field for vm_struct

[Matthew Wilcox]

On Tue, Mar 13, 2018 at 11:45:50PM +0200, Igor Stoppa wrote:
> When a page is used for virtual memory, it is often necessary to obtain
> a handler to the corresponding vm_struct, which refers to the virtually
> continuous area generated when invoking vmalloc.
> 
> The struct page has a "mapping" field, which can be re-used, to store a
> pointer to the parent area.
> 
> This will avoid more expensive searches, later on.
> 
> Signed-off-by: Igor Stoppa 

Reviewed-by: Matthew Wilcox 

Regardless of the fate of the rest of this patchset, this makes sense
and we should have this.

Re: [PATCH 4/8] struct page: add field for vm_struct

[Matthew Wilcox]

On Tue, Mar 13, 2018 at 11:45:50PM +0200, Igor Stoppa wrote:
> When a page is used for virtual memory, it is often necessary to obtain
> a handler to the corresponding vm_struct, which refers to the virtually
> continuous area generated when invoking vmalloc.
> 
> The struct page has a "mapping" field, which can be re-used, to store a
> pointer to the parent area.
> 
> This will avoid more expensive searches, later on.
> 
> Signed-off-by: Igor Stoppa 

Reviewed-by: Matthew Wilcox 

Regardless of the fate of the rest of this patchset, this makes sense
and we should have this.

[PATCH 4/8] struct page: add field for vm_struct

[Igor Stoppa]

When a page is used for virtual memory, it is often necessary to obtain
a handler to the corresponding vm_struct, which refers to the virtually
continuous area generated when invoking vmalloc.

The struct page has a "mapping" field, which can be re-used, to store a
pointer to the parent area.

This will avoid more expensive searches, later on.

Signed-off-by: Igor Stoppa 
---
 include/linux/mm_types.h | 1 +
 mm/vmalloc.c | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index fd1af6b9591d..c3a4825e10c0 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -84,6 +84,7 @@ struct page {
void *s_mem;/* slab first object */
atomic_t compound_mapcount; /* first tail page */
/* page_deferred_list().next -- second tail page */
+   struct vm_struct *area;
};
 
/* Second double word */
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index ebff729cc956..61a1ca22b0f6 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1536,6 +1536,7 @@ static void __vunmap(const void *addr, int 
deallocate_pages)
struct page *page = area->pages[i];
 
BUG_ON(!page);
+   page->area = NULL;
__free_pages(page, 0);
}
 
@@ -1705,6 +1706,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, 
gfp_t gfp_mask,
area->nr_pages = i;
goto fail;
}
+   page->area = area;
area->pages[i] = page;
if (gfpflags_allow_blocking(gfp_mask|highmem_mask))
cond_resched();
-- 
2.14.1

[PATCH 4/8] struct page: add field for vm_struct

[Igor Stoppa]

When a page is used for virtual memory, it is often necessary to obtain
a handler to the corresponding vm_struct, which refers to the virtually
continuous area generated when invoking vmalloc.

The struct page has a "mapping" field, which can be re-used, to store a
pointer to the parent area.

This will avoid more expensive searches, later on.

Signed-off-by: Igor Stoppa 
---
 include/linux/mm_types.h | 1 +
 mm/vmalloc.c | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index fd1af6b9591d..c3a4825e10c0 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -84,6 +84,7 @@ struct page {
void *s_mem;/* slab first object */
atomic_t compound_mapcount; /* first tail page */
/* page_deferred_list().next -- second tail page */
+   struct vm_struct *area;
};
 
/* Second double word */
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index ebff729cc956..61a1ca22b0f6 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1536,6 +1536,7 @@ static void __vunmap(const void *addr, int 
deallocate_pages)
struct page *page = area->pages[i];
 
BUG_ON(!page);
+   page->area = NULL;
__free_pages(page, 0);
}
 
@@ -1705,6 +1706,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, 
gfp_t gfp_mask,
area->nr_pages = i;
goto fail;
}
+   page->area = area;
area->pages[i] = page;
if (gfpflags_allow_blocking(gfp_mask|highmem_mask))
cond_resched();
-- 
2.14.1