From: Dan Smith <danms@us.ibm.com>
To: Michal Nazarewicz <mina86@mina86.com>
Cc: akpm@linux-foundation.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Ensure that walk_page_range()'s start and end are page-aligned
Date: Fri, 10 Feb 2012 11:57:31 -0800 [thread overview]
Message-ID: <874nuy31hw.fsf@caffeine.danplanet.com> (raw)
In-Reply-To: <op.v9hahmw23l0zgt@mpn-glaptop> (Michal Nazarewicz's message of "Fri, 10 Feb 2012 20:45:12 +0100")
MN> Commit message says about walk_pte_range() but commit changes
MN> walk_page_range().
Yep, the issue occurs in walk_pte_range(). The goal was to ensure that
the external interface to it (which is walk_page_range()) does the check
and avoids doing the walk entirely. I think the expectation is that
walk_page_range() is used on aligned addresses. If we put the check in
walk_pte_range() then only walks with a pte_entry handler would fail on
unaligned addresses, which is potentially confusing.
MN> So why not change the condition to addr < end?
That would work, of course, but seems sloppier and less precise. The
existing code was clearly written expecting to walk aligned addresses.
--
Dan Smith
IBM Linux Technology Center
email: danms@us.ibm.com
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next prev parent reply other threads:[~2012-02-10 19:57 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-10 19:39 Dan Smith
2012-02-10 19:45 ` Michal Nazarewicz
2012-02-10 19:57 ` Dan Smith [this message]
2012-02-10 20:13 ` Michal Nazarewicz
2012-02-13 10:12 ` David Rientjes
2012-02-13 14:52 ` Dan Smith
2012-02-13 21:55 ` David Rientjes
2012-02-14 14:59 ` Dan Smith
2012-02-14 21:04 ` David Rientjes
2012-02-15 14:39 ` Dan Smith
2012-02-24 19:19 ` Dan Smith
2012-02-24 20:55 ` Andrew Morton
2012-02-24 21:03 ` Dan Smith
-- strict thread matches above, loose matches on Subject: below --
2012-02-10 15:53 Dan Smith
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