Tim Hockin wrote:
> If we are going to pick an affinity system, please, let's consider sysmp().
Not too bad. I picked a random sysmp(2) man page off the net (attached
for ease of other's reference).
It duplicates some stuff set elsewhere, and seems more than a bit like
ioctl(2) by another name, but doesn't seem too bad. Note we should be
careful not to overengineer the interface, either...
Just setting a bitmask does seem a bit limiting when thinking about the
future, agreed.
-- Jeff Garzik | Usenet Rule #2 (John Gilmore): "The Net interprets Building 1024 | censorship as damage and routes around it." MandrakeSoft | --------------A043F6850FA9706A1CC3A389 Content-Type: text/plain; charset=us-ascii; name="sysmp.man.txt" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="sysmp.man.txt"
sysmp - multiprocessing control
C SYNOPSIS
#include <sys/types.h> #include <sys/sysmp.h> #include <sys/sysinfo.h> /* for SAGET and MINFO structures */ int sysmp (int cmd, ...); ptrdiff_t sysmp (int cmd, ...);"
DESCRIPTION
sysmp provides control/information for miscellaneous system services. This system call is usually used by system programs and is not intended for general use. The arguments arg1, arg2, arg3, arg4 are provided for command-dependent use.
As specified by cmd, the following commands are available:
MP_CLEARCFSSTAT MP_CLEARNFSSTAT MP_NUMA_GETCPUNODEMAP MP_NUMA_GETDISTMATRIX These are all interfaces that are used to implement various system library functions. They are all subject to change and should not be called directly by applications.
MP_PGSIZE The page size of the system is returned (see getpagesize(2)).
MP_SCHED Interface for the schedctl(2) system call.
MP_NPROCS Returns the number of processors physically configured.
MP_NAPROCS Returns the number of processors that are available to schedule unrestricted processes.
MP_STAT The processor ids and status flag bits of the physically configured processors are copied into an array of pda_stat structures to which arg1 points. The array must be large enough to hold as many pda_stat structures as the number of processors returned by the MP_NPROCS sysmp command. The pda_stat structure and the various status bits are defined in <sys/pda.h>.
MP_EMPOWER The processor number given by arg1, interpreted as an 'int', is empowered to run any unrestricted processes. This is the default for all processors. This command requires superuser authority.
MP_RESTRICT The processor number given by arg1, interpreted as an 'int', is restricted from running any processes except those assigned to it by a MP_MUSTRUN or MP_MUSTRUN_PID command, a runon(1) command or because of hardware necessity. Note that processor 0 cannot be restricted. This command requires superuser authority. On Challenge Series machines, all timers belonging to the processor are moved to the processor that owns the clock as reported by MP_CLOCK.
MP_ISOLATE The processor number given by arg1, interpreted as an 'int', is isolated from running any processes except those assigned to it by a MP_MUSTRUN command, a runon(1) command or because of hardware necessity. Instruction cache and Translation Lookaside Buffer synchronization across processors in the system is minimized or delayed on an isolated processor until system services are requested. Note that processor 0 cannot be isolated. This command requires superuser authority. On Challenge Series machines, all timers belonging to the processor are moved to the processor that owns the clock as reported by MP_CLOCK.
MP_UNISOLATE The processor number given by arg1, interpreted as an 'int', is unisolated and empowered to run any unrestricted processes. This is the default system configuration for all processors. This command requires superuser authority.
MP_PREEMPTIVE The processor number given by arg1, interpreted as an 'int', has its clock scheduler enabled. This is the default for all processors. This command requires superuser authority.
MP_NONPREEMPTIVE The processor number given by arg1, interpreted as an 'int', has its clock scheduler disabled. Normal process time slicing is no longer enforced on that processor. As a result of turning off the clock interrupt, the interrupt latency on this processor will be lower. This command requires superuser authority and is allowed only on an isolated processor. This command is not allowed on the clock processor (see MP_CLOCK).
MP_CLOCK The processor number given by arg1, interpreted as an 'int', is given charge of the operating system software clock (see timers(5)). This command requires superuser authority.
MP_FASTCLOCK The processor number given by arg1, interpreted as an 'int', is given charge of the operating system software fast clock (see timers(5)). This command requires superuser authority.
MP_MISER_GETREQUEST MP_MISER_SENDREQUEST MP_MISER_RESPOND MP_MISER_GETRESOURCE MP_MISER_SETRESOURCE MP_MISER_CHECKACCESS These are all interfaces that are used to implement various miser(1) functions. These are all subject to change and should not be called directly by applications.
MP_MUSTRUN Assigns the calling process to run only on the processor number by arg1, interpreted as an 'int', except as required for communications with hardware devices. A process that has allocated a CC sync register (see ccsync(7m)) is restricted to running on a particular cpu. Attempts to reassign such a process to another cpu will fail until the CC sync register has been relinquished.
MP_MUSTRUN_PID Assigns the process specified by arg2 to run only on the processor number specified by arg1, both interpreted as 'int', except as required for communications with hardware devices. A process that has allocated a CC sync register (see ccsync(7m)) is restricted to running on a particular cpu. Attempts to reassign such a process to another cpu will fail until the CC sync register has been relinquished.
MP_GETMUSTRUN Returns the processor the current process has been set to run on using the MP_MUSTRUN command. If the current process has not been assigned to a specific processor, -1 is returned and errno is set to EINVAL.
MP_GETMUSTRUN_PID Returns the processor that the process specified by arg1 has been set to run on using the MP_MUSTRUN or MP_MUSTRUN_PID command. If the process has not been assigned to a specific processor, -1 is returned and errno is set to EINVAL.
MP_RUNANYWHERE Frees the calling process to run on whatever processor the system deems suitable.
MP_RUNANYWHERE_PID Frees the process specified by arg1 to run on whatever processor the system deems suitable.
MP_KERNADDR Returns the address of various kernel data structures. The structure returned is selected by arg1. The list of available structures is detailed in <sys/sysmp.h>. This option is used by many system programs to avoid having to look in /unix for the location of the data structures.
MP_SASZ Returns the size of various system accounting structures. As above, the structure returned is governed by arg1.
MP_SAGET1 Returns the contents of various system accounting structures. The information is only for the processor specified by arg4. As above, the structure returned is governed by arg1. arg2 points to a buffer in the address space of the calling process and arg3 specifies the maximum number of bytes to transfer.
MP_SAGET Returns the contents of various system accounting structures. The information is summed across all processors before it is returned. As above, the structure returned is governed by arg1. arg2 points to a buffer in the address space of the calling process and arg3 specifies the maximum number of bytes to transfer.
Possible errors from sysmp are:
[EPERM] The effective user ID is not superuser. Many of the commands require superuser privilege.
[EPERM] The user ID of the sending process is not superuser, and its real or effective user ID does not match the real, saved, or effective user ID of the receiving process.
[ESRCH] No process corresponding to that specified by a MP_MUSTRUN_PID, MP_GETMUSTRUN_PID, or MP_RUNANYWHERE_PID could be found.
[EINVAL] The processor named by a MP_EMPOWER, MP_RESTRICT, MP_CLOCK or MP_SAGET1 command does not exist.
[EINVAL] The cmd argument is invalid.
[EINVAL] The arg1 argument to a MP_KERNADDR command is invalid.
[EINVAL] An attempt was made via MP_MUSTRUN or MP_MUSTRUN_PID to move a process owning a CC sync register from the cpu controlling the CC sync register.
[EINVAL] The target of the MP_GETMUSTRUN command has not been set to run on a specific processor.
[EBUSY] An attempt was made to restrict the only unrestricted processor or to restrict the master processor.
[EFAULT] An invalid buffer address has been supplied by the calling process.
SEE ALSO
mpadmin(1), runon(1), getpagesize(2), schedctl(2), timers(5)
DIAGNOSTICS
Upon successful completion, the cmd dependent data is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error.
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mpadmin(1) mpadmin(1)
NAME
mpadmin - control and report processor status
SYNOPSIS
mpadmin -n
mpadmin -u[processor]
mpadmin -r[processor]
mpadmin -c[processor]
mpadmin -f[processor]
mpadmin -I[processor]
mpadmin -U[processor]
mpadmin -D[processor]
mpadmin -C[processor]
mpadmin -s
DESCRIPTION
mpadmin provides control/information of processor status.
Exactly one argument is accepted by mpadmin at each invocation. The following arguments are accepted:
-n Report which processors are physically configured. The numbers of the physically configured processors are written to the standard output, one processor number per line. Processors are numbered beginning from 0.
-u[processor] When no processor is specified, the numbers of the processors that are available to schedule unrestricted processes are written to the standard output. Otherwise, mpadmin enables the processor number processor to run any unrestricted processes.
-r[processor] When no processor is specified, the numbers of the processors that are restricted from running any processes (except those assigned via the sysmp(MP_MUSTRUN) function, the runon(1) command, or because of hardware necessity) are written to the standard output. Otherwise, mpadmin restricts the processor numbered processor.
-c[processor] When no processor is specified, the number of the processor that handles the operating system software clock is written to the standard output. Otherwise, operating system software clock handling is moved to the processor numbered processor. See timers(5) for more details.
-f[processor] When no processor is specified, the number of the processor that handles the operating system fast clock is written to the standard output. Otherwise, operating system fast clock handling is moved to the processor numbered processor. See ftimer(1) and timers(5) for a description of the fast clock usage.
-I[processor] When no processor is specified, the numbers of the processors that are isolated are written to the standard output. Otherwise, mpadmin isolates the processor numbered processor. An isolated processor is restricted as by the -r argument. In addition, instruction cache and Translation Lookaside Buffer synchronization are blocked, and synchronization is delayed until a system service is requested.
-U[processor] When no processor is specified, the numbers of the processors that are not isolated are written to the standard output. Otherwise, mpadmin unisolates the processor numbered processor.
-D[processor] When no processor is specified, the numbers of the processors that are not running the clock scheduler are written to the standard output. Otherwise, mpadmin disables the clock scheduler on the processor numbered processor. This makes that processor nonpreemptive, so that normal IRIX process time slicing is no longer enforced. Processes that run on a non-preemptive processor are not preempted because of timer interrupts. They are preempted only when requesting a system service that causes them to wait, or that makes a higher-priority process runnable (for example, posting a semaphore).
-C[processor] When no processor is specified, the numbers of the processors that are running the clock scheduler are written to the standard output. Otherwise, mpadmin enables the clock scheduler on the processor numbered processor. Processes on a preemptive processor can be preempted at the end of their time slice.
-s A summary of the unrestricted, restricted, isolated, preemptive and clock processor numbers is written to the standard output.
SEE ALSO
ftimer(1), runon(1), sysmp(2), timers(5).
DIAGNOSTICS
When an argument specifies a processor, 0 is returned on success, -1 on failure. Otherwise, the number of processors associated with argument is returned.
WARNINGS
It is not possible to restrict or isolate all processors. Processor 0 must never be restricted or isolated.
BUGS
Changing the clock processor may cause the system to lose a small amount of system time.
When a processor is not provided as an argument, mpadmin's exit value will not exceed 255. If more than 255 processors exist, mpadmin will return 0.
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