From: riel@surriel.com (Rik van Riel)
To: kernelnewbies@lists.kernelnewbies.org
Subject: [mm subsystem] A question about function page_table_range_init_count()
Date: Tue, 21 Mar 2017 10:01:23 -0400 [thread overview]
Message-ID: <1490104883.3406.7.camel@surriel.com> (raw)
In-Reply-To: <CA+PpKPmbz=KJvjVqemCxLr3VJfoQUYCMW8C4S930sfDurOYqHw@mail.gmail.com>
On Wed, 2017-03-15 at 22:12 +0800, Hao Lee wrote:
> Hi, all
>
> I encounter a problem when I read the source code of kernel 4.9.9.
>
> In arch/x86/mm/init_32.c, at line 125 [1], there is a function named
> page_table_range_init_count(...). I have analyzed some codes and find
> its two parameters are PKMAP_BASE and FIXADDR_START.
>
> Between Line 141 and Line 150, there is a for loop and I don't know
> what it means, especially Line 144-Line147.
>
> Could someone can give me some tips. Thanks a lot!
>
The code iterates over the virtual memory addresses
specified, and counts the number of pmds (second level
page tables) that will be needed to map that address
space.
prev parent reply other threads:[~2017-03-21 14:01 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-15 14:12 [mm subsystem] A question about function page_table_range_init_count() Hao Lee
2017-03-21 14:01 ` Rik van Riel [this message]
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