[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <46999253.6020004@zytor.com>
Date: Sat, 14 Jul 2007 20:19:47 -0700
From: "H. Peter Anvin" <hpa@...or.com>
To: Albert Cahalan <acahalan@...il.com>
CC: olaf@...fle.de, akpm@...ux-foundation.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH] remove PAGE_SIZE from headers_install
Albert Cahalan wrote:
>
> A real constant-value PAGE_SIZE is useful and doable.
>
> It's useful because a getpagesize() can't be used for numerous
> things, such as setting the size of an array.
>
> It's doable, even on architectures that support multiple page
> sizes, because ABIs specify alignment requirements. There are
> two alignments of interest here:
>
> a. the smallest that mmap() will ever naturally return on any
> correct implementation of the architecture's ABI ("naturally"
> meaning that MAP_FIXED was not used)
>
> b. the smallest that mprotect() will tolerate on all
> correct implementations of the architecture
>
> Pick either to be the Linux definition of PAGE_SIZE.
>
If you specify it to be one of these, people will mis-use it for the
other. This is a bad idea.
-hpa
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists