From: Andrew Morton <akpm@linux-foundation.org>
To: Mina Almasry <almasrymina@google.com>
Cc: Ken Chen <kenchen@google.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Chris Kennelly <ckennelly@google.com>
Subject: Re: [PATCH v1] mm, hugepages: add mremap() support for hugepage backed vma
Date: Sun, 1 Aug 2021 12:49:17 -0700 [thread overview]
Message-ID: <20210801124917.ca6fce3972866dc738bfcb7b@linux-foundation.org> (raw)
In-Reply-To: <20210730221522.524256-1-almasrymina@google.com>
On Fri, 30 Jul 2021 15:15:22 -0700 Mina Almasry <almasrymina@google.com> wrote:
> Support mremap() for hugepage backed vma segment by simply repositioning
> page table entries. The page table entries are repositioned to the new
> virtual address on mremap().
>
> Hugetlb mremap() support is of course generic; my motivating use case
> is a library (hugepage_text), which reloads the ELF text of executables
> in hugepages. This significantly increases the execution performance of
> said executables.
>
> Restricts the mremap operation on hugepages to up to the size of the
> original mapping as the underlying hugetlb reservation is not yet
> capable of handling remapping to a larger size.
>
> Tested with a simple mmap/mremap test case, roughly:
>
> void* haddr = mmap(NULL, size, PROT_READ | PROT_WRITE | PROT_EXEC,
> MAP_ANONYMOUS | MAP_SHARED, -1, 0);
>
> void* taddr = mmap(NULL, size, PROT_NONE,
> MAP_HUGETLB | MAP_ANONYMOUS | MAP_SHARED, -1, 0);
>
> void* raddr = mremap(haddr, size, size, MREMAP_MAYMOVE | MREMAP_FIXED, taddr);
Could we please get testing for this added into tools/testing/selftests/?
next prev parent reply other threads:[~2021-08-01 19:49 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-30 22:15 [PATCH v1] mm, hugepages: add mremap() support for hugepage backed vma Mina Almasry
2021-08-01 19:49 ` Andrew Morton [this message]
2021-08-01 23:12 ` Mina Almasry
2021-08-02 23:50 ` Mike Kravetz
2021-08-04 18:03 ` Mina Almasry
2021-08-05 16:56 ` Mike Kravetz
2021-08-11 0:52 ` Mina Almasry
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210801124917.ca6fce3972866dc738bfcb7b@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=almasrymina@google.com \
--cc=ckennelly@google.com \
--cc=kenchen@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mike.kravetz@oracle.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).