cpusetGetFlags(3x)

NAME
     cpusetGetFlags - get the mask of flags for a cpuset

SYNOPSIS
     #include <cpuset.h>

     int cpusetGetFlags(char *qname, int *flags);

DESCRIPTION
     The cpusetGetFlags function is used to obtain the attribute flags used
     when creating a cpuset.  The mask of flags will be copied into the memory
     referenced by the flags argument.

     Only processes running with a user ID or group ID that has read access
     permissions on the permissions file can successfully execute this
     function.  The qname argument is the name of the specified cpuset.

     The return value of the function indicates if the function was
     successfully executed.

     The mask of flags can be set to any of the following values:

     CPUSET_CPU_EXCLUSIVE
            Defines a cpuset to be restricted.  Only threads attached to the
            cpuset queue (descendents of an attached thread inherit the
            attachement) may execute on the CPUs contained in the cpuset.

     CPUSET_MEMORY_LOCAL
            Threads assigned to the cpuset will attempt to assign memory only
            from nodes within the cpuset.  Assignment of memory from outside
            the cpuset will occur only if no free memory is available from
            within the cpuset.  No restrictions are made on memory assignment
            to threads running outside the cpuset.

     CPUSET_MEMORY_EXCLUSIVE
            Threads assigned to the cpuset will attempt to assign memory only
            from nodes within the cpuset.  Assignment of memory from outside
            the cpuset will occur only if no free memory is available from
            within the cpuset.  Threads not assigned to the cpuset will not
            use memory from within the cpuset unless no memory outside the
            cpuset is available.  If, at the time a cpuset is created, memory
            is already assigned to threads that are already running, no
            attempt will be made to explicitly move this memory.  If page
            migration is enabled, the pages will be migrated when the system
            detects that most references to the pages are non-local.

     CPUSET_MEMORY_KERNEL_AVOID
            The kernel should attempt to avoid allocating memory from nodes
            contained in this cpuset. If kernel memory requests cannot be
            satisfied from outside this cpuset, this option will be ignored
            and allocations will occur from within the cpuset. (This avoidance
            currently extends only to keeping buffer cache away from the
            protected nodes.)

     CPUSET_MEMORY_MANDATORY
            The kernel will limit all memory allocations to nodes that are
            contained in this cpuset. If memory requests cannot be satisfied,
            the allocating process will sleep until memory is available. The
            process will be killed if no more memory can be allocated. See
            policies below.

     CPUSET_POLICY_PAGE
            Requires MEMORY_MANDATORY. This is the default policy if no policy
            is specified. This policy will cause the kernel to page user pages
            to the swap file (see swap(1M)) to free physical memory on the
            nodes contained in this cpuset. If swap space is exhausted, the
            process will be killed.

     CPUSET_POLICY_KILL
            Requires MEMORY_MANDATORY. The kernel will attempt to free as much
            space as possible from kernel heaps, but will not page user pages
            to the swap file.  If all physical memory on the nodes contained
            in this cpuset are exhausted, the process will be killed.

     CPUSET_POLICY_SHARE_WARN
            When creating a cpuset, if it is possible for the new cpuset to
            share memory on a node with another cpuset the new cpuset will be
            created but a warning message will be issued.  POLICY_SHARE_WARN
            and POLICY_SHARE_FAIL cannot be used together.

     CPUSET_POLICY_SHARE_FAIL
            When creating a cpuset, if it is possible for the new cpuset to
            share memory on a node with another cpuset the new cpuset will
            fail to be created and an error message will be issued.
            POLICY_SHARE_WARN and POLICY_SHARE_FAIL cannot be used together.

EXAMPLES
     This example prints out the flags defined for the cpuset mpi_set.

               char             *qname = "mpi_set";
               int              flags;

               /* Get the limits else print error & exit */
               if (!cpusetGetFlags(qname, &flags)) ) {
                   perror("cpusetGetFlags");
                   exit(1);
               }
               if (flags & CPUSET_CPU_EXCLUSIVE)
                   printf("    CPU_EXCLUSIVE0);
               if (flags & CPUSET_EXPLICIT)
                   printf("    CPU)_EXPLICIT0);
               if (flags & CPUSET_KERN)
                   printf("    KERN0);
               if (flags & CPUSET_MEMORY_LOCAL)
                   printf("    MEMORY_LOCAL0);
               if (flags & CPUSET_MEMORY_EXCLUSIVE)
                   printf("    MEMORY_EXCLUSIVE0);
               if (flags & CPUSET_MEMORY_KERNEL_AVOID)
                   printf("    MEMORY_KERNEL_AVOID0);
               if (flags & CPUSET_MEMORY_MANDATORY)
                   printf("    MEMORY_MANDATORY0);
               if (flags & CPUSET_POLICY_PAGE)
                   printf("    POLICY_PAGE0);
               if (flags & CPUSET_POLICY_KILL)
                   printf("    POLICY_KILL0);
               if (flags & CPUSET_POLICY_SHARE_WARN)
                   printf("    POLICY_SHARE_WARN0);
               if (flags & CPUSET_POLICY_SHARE_FAIL)
                   printf("    POLICY_SHARE_FAIL0);



NOTES
     cpusetGetFlags is found in the library "libcpuset.so", and will be loaded
     if the option -lcpuset is used with cc(1) or ld(1).

SEE ALSO
     cpuset(1), cpusetSetFlags(3x), cpuset(5).

DIAGNOSTICS
     If successful, cpusetGetFlags returns 1.  If cpusetGetFlags fails, it
     returns 0 and errno is set to indicate the error.  The possible values
     for errno include those values as set by sysmp(2) and sbrk(2).