SPU_CREATE(2) Linux Programmer's Manual SPU_CREATE(2)
spu_create - create a new spu context
int spu_create(const char *pathname, int flags, mode_t mode);
int spu_create(const char *pathname, int flags, mode_t mode,
Note: There is no glibc wrapper for this system call; see NOTES.
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 pathname and returns a file descriptor associated with
it. pathname must refer to a nonexistent directory in the mount point of the SPU file
system (spufs). If spu_create() is successful, a directory is created at pathname 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 pathname directory) once the last reference to the con-
text has gone; this usually occurs when the file descriptor returned by spu_create() is
The flags argument can be zero or any bitwise OR-ed combination of the following con-
Rather than using signals for reporting DMA errors, use the event argument to
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 parame-
ters--priority and policy. In the future, gang scheduling may be implemented caus-
ing the group to be switched in and out as a single unit.)
A new directory will be created at the location specified by the pathname 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().
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.
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.
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 argu-
Create a context with affinity to system memory. This affinity information is used
within the SPU scheduling algorithm.
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
On success, spu_create() returns a new file descriptor. On error, -1 is returned, and
errno is set to one of the error codes listed below.
EACCES The current user does not have write access to the spufs(7) mount point.
EEXIST An SPU context already exists at the given path name.
EFAULT pathname is not a valid string pointer in the calling process's address space.
EINVAL pathname is not a directory in the spufs(7) mount point, or invalid flags have been
ELOOP Too many symbolic links were found while resolving pathname.
EMFILE The process has reached its maximum open files limit.
pathname is too long.
ENFILE The system has reached the global open files limit.
ENODEV An isolated context was requested, but the hardware does not support SPU isolation.
ENOENT Part of pathname 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 hard-
ware does not provide SPUs or the spufs module is not loaded.
A part of pathname is not a directory.
EPERM The SPU_CREATE_NOSCHED flag has been given, but the user does not have the
pathname must point to a location beneath the mount point of spufs. By convention, it
gets mounted in /spu.
The spu_create() system call was added to Linux in kernel 2.6.16.
This call is Linux-specific and implemented only on the PowerPC architecture. Programs
using this system call are not portable.
Glibc does not provide a wrapper for this system call; call it using syscall(2). Note
however, that 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 release 3.53 of the Linux man-pages project. A description of the
project, and information about reporting bugs, can be found at
Linux 2012-08-05 SPU_CREATE(2)