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Message-ID: <68a9b3aa-d064-ed6a-2bcd-9423eb4f595c@infradead.org>
Date:   Sat, 1 Jul 2023 08:21:20 -0700
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Subject: Re: [PATCH v2] Documentation/mm: Add information about
 kmap_local_folio()
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To:     "Fabio M. De Francesco" <fmdefrancesco@gmail.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Andrew Morton <akpm@linux-foundation.org>,
        "Mike Rapoport (IBM)" <rppt@kernel.org>,
        Deming Wang <wangdeming@inspur.com>,
        Ira Weiny <ira.weiny@intel.com>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc:     Catalin Marinas <catalin.marinas@arm.com>,
        Matthew Wilcox <willy@infradead.org>,
        Mike Rapoport <rppt@linux.ibm.com>,
        Peter Collingbourne <pcc@google.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Vlastimil Babka <vbabka@suse.cz>, Will Deacon <will@kernel.org>
References: <20230701142041.9992-1-fmdefrancesco@gmail.com>
From:   Randy Dunlap <rdunlap@infradead.org>
In-Reply-To: <20230701142041.9992-1-fmdefrancesco@gmail.com>
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On 7/1/23 07:19, Fabio M. De Francesco wrote:

> 
> v1->v2: I thought to Cc everybody but Andrew :-( Sorry, fixed.
> 	Andrew, can you please take this patch through your tree?
> 
>  Documentation/mm/highmem.rst | 27 +++++++++++++++------------
>  1 file changed, 15 insertions(+), 12 deletions(-)
> 
> diff --git a/Documentation/mm/highmem.rst b/Documentation/mm/highmem.rst
> index c964e0848702..bb9584f167a6 100644
> --- a/Documentation/mm/highmem.rst
> +++ b/Documentation/mm/highmem.rst
> @@ -51,11 +51,14 @@ Temporary Virtual Mappings
>  The kernel contains several ways of creating temporary mappings. The following
>  list shows them in order of preference of use.
>  
> -* kmap_local_page().  This function is used to require short term mappings.
> -  It can be invoked from any context (including interrupts) but the mappings
> -  can only be used in the context which acquired them.
> -
> -  This function should always be used, whereas kmap_atomic() and kmap() have
> +* kmap_local_page(), kmap_local_folio() - These functions are used to require

                                                                         acquire ?

> +  short term mappings. They can be invoked from any context (including
> +  interrupts) but the mappings can only be used in the context which acquired
> +  them. The only differences between them consist in the first taking a pointer
> +  to a struct page and the second taking a pointer to struct folio and the byte
> +  offset within the folio which identifies the page.

-- 
~Randy