From: Mike Kravetz <mike.kravetz@oracle.com>
To: Li Xinhai <lixinhai.lxh@gmail.com>,
John Hubbard <jhubbard@nvidia.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>
Cc: Linux API <linux-api@vger.kernel.org>, akpm <akpm@linux-foundation.org>
Subject: Re: [PATCH] mm: allow checking length for hugetlb mapping in mmap()
Date: Tue, 31 Mar 2020 15:04:54 -0700 [thread overview]
Message-ID: <e8e8ea0b-f912-2084-ee28-d4da1968e70a@oracle.com> (raw)
In-Reply-To: <2020033116350399980494@gmail.com>
On 3/31/20 1:35 AM, Li Xinhai wrote:
> My understanding may wrong, but it seems that once some application start to use
> some behavior of kernel, although that usage in user space is not logical, they
> will be protected from change in kernel side.
Correct. I too wish that the length argument to mmap for hugetlb mappings
was required to be a multiple of huge page size. That would make everything
nice and consistent. However, the behavior of rounding the length up to huge
page size has existed for quite some time and it well documented. Therefore,
we can not change it without the possibility of breaking some application.
--
Mike Kravetz
prev parent reply other threads:[~2020-03-31 22:07 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-29 3:08 [PATCH] mm: allow checking length for hugetlb mapping in mmap() Li Xinhai
2020-03-29 3:53 ` John Hubbard
2020-03-29 8:09 ` Li Xinhai
2020-03-30 18:39 ` Mike Kravetz
2020-03-31 8:35 ` Li Xinhai
2020-03-31 22:04 ` Mike Kravetz [this message]
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