From: Jack Steiner <steiner@sgi.com>
To: linux-ia64@vger.kernel.org
Subject: Re: [PATCH] - deleting huge pages
Date: Mon, 03 May 2004 19:47:32 +0000 [thread overview]
Message-ID: <20040503194732.GA22056@sgi.com> (raw)
In-Reply-To: <20040502123028.GA13812@sgi.com>
(Update to previous mail - patch updated for latest tree)
If you attempt to allocate a LOT more huge pages than are physically
available, the kernel may reference a NULL pte.
If the mmap fails, do_mmap_pgoff attempts to unmap the vma range it
was mapping. Depending on where it failed during
the mmap, some of the higher level PGD/PMDs may not have been assigned.
The same problem exists in 2.4. I'll post a second patch in a few
days....
--- linux_base/arch/ia64/mm/hugetlbpage.c 2004-05-03 09:36:00.000000000 -0500
+++ linux/arch/ia64/mm/hugetlbpage.c 2004-05-03 14:38:21.000000000 -0500
@@ -245,7 +245,7 @@
for (address = start; address < end; address += HPAGE_SIZE) {
pte = huge_pte_offset(mm, address);
- if (pte_none(*pte))
+ if (!pte || pte_none(*pte))
continue;
page = pte_page(*pte);
put_page(page);
--
Thanks
Jack Steiner (steiner@sgi.com) 651-683-5302
Principal Engineer SGI - Silicon Graphics, Inc.
prev parent reply other threads:[~2004-05-03 19:47 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-05-02 12:30 [PATCH] - deleting huge pages Jack Steiner
2004-05-02 18:33 ` Chen, Kenneth W
2004-05-03 14:53 ` Jack Steiner
2004-05-03 17:12 ` Chen, Kenneth W
2004-05-03 19:47 ` Jack Steiner [this message]
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