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NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | FILES | STANDARDS | HISTORY | NOTES | EXAMPLES | SEE ALSO | COLOPHON |
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spu_create(2) System Calls Manual spu_create(2)
spu_create - create a new spu context
Standard C library (libc, -lc)
#include <sys/spu.h> /* Definition of SPU_* constants */
#include <sys/syscall.h> /* Definition of SYS_* constants */
#include <unistd.h>
int syscall(SYS_spu_create, const char *path, unsigned int flags,
mode_t mode, int neighbor_fd);
Note: glibc provides no wrapper for spu_create(), necessitating
the use of syscall(2).
The spu_create() system call is used on PowerPC machines that
implement the Cell Broadband Engine Architecture in order to
access Synergistic Processor Units (SPUs). It creates a new
logical context for an SPU in path and returns a file descriptor
associated with it. path must refer to a nonexistent directory in
the mount point of the SPU filesystem (spufs). If spu_create() is
successful, a directory is created at path and it is populated
with the files described in spufs(7).
When a context is created, the returned file descriptor can only
be passed to spu_run(2), used as the dirfd argument to the *at
family of system calls (e.g., openat(2)), or closed; other
operations are not defined. A logical SPU context is destroyed
(along with all files created within the context's path directory)
once the last reference to the context has gone; this usually
occurs when the file descriptor returned by spu_create() is
closed.
The mode argument (minus any bits set in the process's umask(2))
specifies the permissions used for creating the new directory in
spufs. See stat(2) for a full list of the possible mode values.
The neighbor_fd is used only when the SPU_CREATE_AFFINITY_SPU flag
is specified; see below.
The flags argument can be zero or any bitwise OR-ed combination of
the following constants:
SPU_CREATE_EVENTS_ENABLED
Rather than using signals for reporting DMA errors, use the
event argument to spu_run(2).
SPU_CREATE_GANG
Create an SPU gang instead of a context. (A gang is a
group of SPU contexts that are functionally related to each
other and which share common scheduling parameters—priority
and policy. In the future, gang scheduling may be
implemented causing the group to be switched in and out as
a single unit.)
A new directory will be created at the location specified
by the path argument. This gang may be used to hold other
SPU contexts, by providing a pathname that is within the
gang directory to further calls to spu_create().
SPU_CREATE_NOSCHED
Create a context that is not affected by the SPU scheduler.
Once the context is run, it will not be scheduled out until
it is destroyed by the creating process.
Because the context cannot be removed from the SPU, some
functionality is disabled for SPU_CREATE_NOSCHED contexts.
Only a subset of the files will be available in this
context directory in spufs. Additionally,
SPU_CREATE_NOSCHED contexts cannot dump a core file when
crashing.
Creating SPU_CREATE_NOSCHED contexts requires the
CAP_SYS_NICE capability.
SPU_CREATE_ISOLATE
Create an isolated SPU context. Isolated contexts are
protected from some PPE (PowerPC Processing Element)
operations, such as access to the SPU local store and the
NPC register.
Creating SPU_CREATE_ISOLATE contexts also requires the
SPU_CREATE_NOSCHED flag.
SPU_CREATE_AFFINITY_SPU (since Linux 2.6.23)
Create a context with affinity to another SPU context.
This affinity information is used within the SPU scheduling
algorithm. Using this flag requires that a file descriptor
referring to the other SPU context be passed in the
neighbor_fd argument.
SPU_CREATE_AFFINITY_MEM (since Linux 2.6.23)
Create a context with affinity to system memory. This
affinity information is used within the SPU scheduling
algorithm.
On success, spu_create() returns a new file descriptor. On
failure, -1 is returned, and errno is set to indicate the error.
EACCES The current user does not have write access to the spufs(7)
mount point.
EEXIST An SPU context already exists at the given pathname.
EFAULT path is not a valid string pointer in the calling process's
address space.
EINVAL path is not a directory in the spufs(7) mount point, or
invalid flags have been provided.
ELOOP Too many symbolic links were found while resolving path.
EMFILE The per-process limit on the number of open file
descriptors has been reached.
ENAMETOOLONG
path is too long.
ENFILE The system-wide limit on the total number of open files has
been reached.
ENODEV An isolated context was requested, but the hardware does
not support SPU isolation.
ENOENT Part of path could not be resolved.
ENOMEM The kernel could not allocate all resources required.
ENOSPC There are not enough SPU resources available to create a
new context or the user-specific limit for the number of
SPU contexts has been reached.
ENOSYS The functionality is not provided by the current system,
because either the hardware does not provide SPUs or the
spufs module is not loaded.
ENOTDIR
A part of path is not a directory.
EPERM The SPU_CREATE_NOSCHED flag has been given, but the user
does not have the CAP_SYS_NICE capability.
path must point to a location beneath the mount point of spufs.
By convention, it gets mounted in /spu.
Linux on PowerPC.
Linux 2.6.16.
Prior to the addition of the SPU_CREATE_AFFINITY_SPU flag in Linux
2.6.23, the spu_create() system call took only three arguments
(i.e., there was no neighbor_fd argument).
spu_create() is meant to be used from libraries that implement a
more abstract interface to SPUs, not to be used from regular
applications. See
⟨http://www.bsc.es/projects/deepcomputing/linuxoncell/⟩ for the
recommended libraries.
See spu_run(2) for an example of the use of spu_create()
close(2), spu_run(2), capabilities(7), spufs(7)
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.15.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2025-08-11. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
[email protected]
Linux man-pages 6.15 2025-05-17 spu_create(2)
Pages that refer to this page: spu_run(2), syscalls(2), spufs(7)
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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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