[PATCH] Documentation: highmem: Use literal block for *kmap_local_folio() example

[PATCH] Documentation: highmem: Use literal block for *kmap_local_folio() example

[Bagas Sanjaya]

When building htmldocs on Linus' tree, there are inline emphasis warnings
on include/linux/highmem.h:

Documentation/vm/highmem:166: ./include/linux/highmem.h:154: WARNING: Inline emphasis start-string without end-string.
Documentation/vm/highmem:166: ./include/linux/highmem.h:157: WARNING: Inline emphasis start-string without end-string.

These warnings above are due to comments in code example of
*kmap_local_folio() are enclosed by double dash (--) instead of prefixed
with comment symbol (#).

Fix these warnings by indenting the code example with literal block
indentation and prefixing comments inside the example with #.

Fixes: 85a85e7601263f ("Documentation/vm: move "Using kmap-atomic" to highmem.h")
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 include/linux/highmem.h | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 3af34de54330cb..a244e0345c87ca 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -149,19 +149,19 @@ static inline void *kmap_local_folio(struct folio *folio, size_t offset);
  * It is used in atomic context when code wants to access the contents of a
  * page that might be allocated from high memory (see __GFP_HIGHMEM), for
  * example a page in the pagecache.  The API has two functions, and they
- * can be used in a manner similar to the following:
+ * can be used in a manner similar to the following::
  *
- * -- Find the page of interest. --
- * struct page *page = find_get_page(mapping, offset);
+ *   # Find the page of interest.
+ *   struct page *page = find_get_page(mapping, offset);
  *
- * -- Gain access to the contents of that page. --
- * void *vaddr = kmap_atomic(page);
+ *   # Gain access to the contents of that page.
+ *   void *vaddr = kmap_atomic(page);
  *
- * -- Do something to the contents of that page. --
- * memset(vaddr, 0, PAGE_SIZE);
+ *   # Do something to the contents of that page.
+ *   memset(vaddr, 0, PAGE_SIZE);
  *
- * -- Unmap that page. --
- * kunmap_atomic(vaddr);
+ *   # Unmap that page.
+ *   kunmap_atomic(vaddr);
  *
  * Note that the kunmap_atomic() call takes the result of the kmap_atomic()
  * call, not the argument.

base-commit: b13baccc3850ca8b8cccbf8ed9912dbaa0fdf7f3
-- 
An old man doll... just what I always wanted! - Clara

Re: [PATCH] Documentation: highmem: Use literal block for *kmap_local_folio() example

[Matthew Wilcox]

On Tue, Jun 14, 2022 at 07:31:16PM +0700, Bagas Sanjaya wrote:
> When building htmldocs on Linus' tree, there are inline emphasis warnings
> on include/linux/highmem.h:
> 
> Documentation/vm/highmem:166: ./include/linux/highmem.h:154: WARNING: Inline emphasis start-string without end-string.
> Documentation/vm/highmem:166: ./include/linux/highmem.h:157: WARNING: Inline emphasis start-string without end-string.
> 
> These warnings above are due to comments in code example of
> *kmap_local_folio() are enclosed by double dash (--) instead of prefixed
> with comment symbol (#).

That's clearly the code example for kmap_atomic(), not
kmap_local_folio().

> Fix these warnings by indenting the code example with literal block
> indentation and prefixing comments inside the example with #.
> 
> Fixes: 85a85e7601263f ("Documentation/vm: move "Using kmap-atomic" to highmem.h")
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
> Cc: "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Cc: linux-mm@kvack.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
> ---
>  include/linux/highmem.h | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/include/linux/highmem.h b/include/linux/highmem.h
> index 3af34de54330cb..a244e0345c87ca 100644
> --- a/include/linux/highmem.h
> +++ b/include/linux/highmem.h
> @@ -149,19 +149,19 @@ static inline void *kmap_local_folio(struct folio *folio, size_t offset);
>   * It is used in atomic context when code wants to access the contents of a
>   * page that might be allocated from high memory (see __GFP_HIGHMEM), for
>   * example a page in the pagecache.  The API has two functions, and they
> - * can be used in a manner similar to the following:
> + * can be used in a manner similar to the following::
>   *
> - * -- Find the page of interest. --
> - * struct page *page = find_get_page(mapping, offset);
> + *   # Find the page of interest.
> + *   struct page *page = find_get_page(mapping, offset);
>   *
> - * -- Gain access to the contents of that page. --
> - * void *vaddr = kmap_atomic(page);
> + *   # Gain access to the contents of that page.
> + *   void *vaddr = kmap_atomic(page);
>   *
> - * -- Do something to the contents of that page. --
> - * memset(vaddr, 0, PAGE_SIZE);
> + *   # Do something to the contents of that page.
> + *   memset(vaddr, 0, PAGE_SIZE);
>   *
> - * -- Unmap that page. --
> - * kunmap_atomic(vaddr);
> + *   # Unmap that page.
> + *   kunmap_atomic(vaddr);
>   *
>   * Note that the kunmap_atomic() call takes the result of the kmap_atomic()
>   * call, not the argument.
> 
> base-commit: b13baccc3850ca8b8cccbf8ed9912dbaa0fdf7f3
> -- 
> An old man doll... just what I always wanted! - Clara
> 

Re: [PATCH] Documentation: highmem: Use literal block for *kmap_local_folio() example

[Bagas Sanjaya]

On 6/14/22 20:08, Matthew Wilcox wrote:
> On Tue, Jun 14, 2022 at 07:31:16PM +0700, Bagas Sanjaya wrote:
>> These warnings above are due to comments in code example of
>> *kmap_local_folio() are enclosed by double dash (--) instead of prefixed
>> with comment symbol (#).
> 
> That's clearly the code example for kmap_atomic(), not
> kmap_local_folio().
> 

Ah! I don't see void *vaddr that make use of kmap_atomic(). Thanks
for reminding.

-- 
An old man doll... just what I always wanted! - Clara

Re: [PATCH] Documentation: highmem: Use literal block for *kmap_local_folio() example

[Ira Weiny]

On Tue, Jun 14, 2022 at 07:31:16PM +0700, Bagas Sanjaya wrote:
> When building htmldocs on Linus' tree, there are inline emphasis warnings
> on include/linux/highmem.h:
> 
> Documentation/vm/highmem:166: ./include/linux/highmem.h:154: WARNING: Inline emphasis start-string without end-string.
> Documentation/vm/highmem:166: ./include/linux/highmem.h:157: WARNING: Inline emphasis start-string without end-string.

Nice catch.

> 
> These warnings above are due to comments in code example of
> *kmap_local_folio() are enclosed by double dash (--) instead of prefixed

As Willy said these are for kmap_atomic()

> with comment symbol (#).

I'd rather see '//' used since this is C code and it makes the output
consistent with C syntax rather than mixing shell and C.

Thanks for the fixup!
Ira


diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index a244e0345c87..56d6a0196534 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -151,16 +151,16 @@ static inline void *kmap_local_folio(struct folio *folio, size_t offset);
  * example a page in the pagecache.  The API has two functions, and they
  * can be used in a manner similar to the following::
  *
- *   # Find the page of interest.
+ *   // Find the page of interest.
  *   struct page *page = find_get_page(mapping, offset);
  *
- *   # Gain access to the contents of that page.
+ *   // Gain access to the contents of that page.
  *   void *vaddr = kmap_atomic(page);
  *
- *   # Do something to the contents of that page.
+ *   // Do something to the contents of that page.
  *   memset(vaddr, 0, PAGE_SIZE);
  *
- *   # Unmap that page.
+ *   // Unmap that page.
  *   kunmap_atomic(vaddr);
  *
  * Note that the kunmap_atomic() call takes the result of the kmap_atomic()


> 
> Fix these warnings by indenting the code example with literal block
> indentation and prefixing comments inside the example with #.
> 
> Fixes: 85a85e7601263f ("Documentation/vm: move "Using kmap-atomic" to highmem.h")
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
> Cc: "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Cc: linux-mm@kvack.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
> ---
>  include/linux/highmem.h | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/include/linux/highmem.h b/include/linux/highmem.h
> index 3af34de54330cb..a244e0345c87ca 100644
> --- a/include/linux/highmem.h
> +++ b/include/linux/highmem.h
> @@ -149,19 +149,19 @@ static inline void *kmap_local_folio(struct folio *folio, size_t offset);
>   * It is used in atomic context when code wants to access the contents of a
>   * page that might be allocated from high memory (see __GFP_HIGHMEM), for
>   * example a page in the pagecache.  The API has two functions, and they
> - * can be used in a manner similar to the following:
> + * can be used in a manner similar to the following::
>   *
> - * -- Find the page of interest. --
> - * struct page *page = find_get_page(mapping, offset);
> + *   # Find the page of interest.
> + *   struct page *page = find_get_page(mapping, offset);
>   *
> - * -- Gain access to the contents of that page. --
> - * void *vaddr = kmap_atomic(page);
> + *   # Gain access to the contents of that page.
> + *   void *vaddr = kmap_atomic(page);
>   *
> - * -- Do something to the contents of that page. --
> - * memset(vaddr, 0, PAGE_SIZE);
> + *   # Do something to the contents of that page.
> + *   memset(vaddr, 0, PAGE_SIZE);
>   *
> - * -- Unmap that page. --
> - * kunmap_atomic(vaddr);
> + *   # Unmap that page.
> + *   kunmap_atomic(vaddr);
>   *
>   * Note that the kunmap_atomic() call takes the result of the kmap_atomic()
>   * call, not the argument.
> 
> base-commit: b13baccc3850ca8b8cccbf8ed9912dbaa0fdf7f3
> -- 
> An old man doll... just what I always wanted! - Clara
>