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56 lines
2.3 KiB
XML
56 lines
2.3 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
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<pkgmetadata>
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<longdescription lang="en">
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This is an experimental version of XPMEM based on a version provided by
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Cray and uploaded to https://code.google.com/p/xpmem. This version supports
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any kernel 3.12 and newer. Keep in mind there may be bugs and this version
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may cause kernel panics, code crashes, eat your cat, etc.
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XPMEM is a Linux kernel module that enables a process to map the
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memory of another process into its virtual address space. Source code
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can be obtained by cloning the Git repository, original Mercurial
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repository or by downloading a tarball from the link above.
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The XPMEM API has three main functions:
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xpmem_make()
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xpmem_get()
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xpmem_attach()
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A process calls xpmem_make() to export a region of its virtual address
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space. Other processes can then attach to the region by calling
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xpmem_get() and xpmem_attach(). After a memory region is attached, it
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is accessed via direct loads and stores. This enables upper-level
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protocols such as MPI and SHMEM to perform single-copy address-space
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to address-space transfers, completely at user-level.
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Note, there is a limitation to the usage of an attached region. Any
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system call that will call get_user_pages() on the region from the
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non-owning process with get EFAULT. This include pthread mutexes
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and condition variable, and SYS V semaphores. We intend to address
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this limitation in a future release.
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XPMEM regions are free to have "holes" in them, meaning virtual memory
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regions that are not allocated. This makes XPMEM somewhat more
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flexible than mmap(). A process could, for example, export a region
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via XPMEM starting at address 0 and extending 4 GB. Accesses to
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allocated (valid) virtual addresses in this region proceed normally,
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and pages are mapped between address spaces on demand. A segfault will
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occur if the source process or any other process mapping the region
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tries to access an unallocated (invalid) virtual address in the
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region.
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</longdescription>
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<maintainer type="person">
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<email>lssndrbarbieri@gmail.com</email>
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<name>Alessandro Barbieri</name>
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</maintainer>
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<use>
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<flag name="modules">Build the kernel module</flag>
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</use>
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<upstream>
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<bugs-to>https://github.com/hjelmn/xpmem/issues</bugs-to>
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<remote-id type="github">hjelmn/xpmem</remote-id>
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</upstream>
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</pkgmetadata>
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