Determines the nature of the DLPAR request.
The dr_reconfig system call is used by DLPAR-aware applications to adjust their use of resources in relation to a DLPAR request. Applications are notified about the usage through the SIGRECONFIG signal, which is generated three times for each DLPAR event.
The first time is to check with the application whether the DLPAR event should be continued. Using the DR_EVENT_FAIL flag, an application can indicate that the operation should be aborted, if it is not DLPAR-safe and its operation is considered vital to the system.
The application is notified the second time before the resource is added or removed, and the third time afterwards. Applications must attempt to control their scheduling priority and policy to guarantee timely delivery of signals. The system does not guarantee that every signal that is sent is delivered before advancing to the next step in the algorithm.
The dr_reconfig system call can also be used to notify applications about the changes to the workload partition that they are running. Applications are notified about changes to the CPU, memory capacity, and resources set.
The dr_reconfig interface is signal-handler safe and can be used by multi-threaded programs.
The dr_info structure is declared within the address space of the application. The kernel fills out data in this structure relative to the current DLPAR request. The user passes this structure identifying the current DLPAR request, as a parameter to the kernel when the DR_RECONFIG_DONE flag is used. The DR_RECONFIG_DONE flag is used by the application to notify the kernel that necessary action to adjust their use of resources has been taken in response to the SIGRECONFIG signal sent to them. It is expected that the signal handler associated with the SIGRECONFIG signal calls the interface with the DR_QUERY flag to identify the phase of the DLPAR event, takes the appropriate action, and calls the interface with the DR_RECONFIG_DONE flag to indicate to the kernel that the signal has been handled. This type of acknowledgment to the kernel in each of the DLPAR phases enables a DLPAR event to perform efficiently.
With the addition of new fields to the dr_info structure, DR-aware applications can support Micro-Partitioning®.
The plock and pshm bits are only set, if the request is to remove memory and the process has plock memory or is attached to a pinned shared memory segment. If the plock bit is set, the process callsplock to unpin itself. If the pshm bit is set, the application has pinned shared memory segments, which may need to be detached. The memory remove request can succeed in any case, if there is enough pinnable memory in the system, so an action in this case is not necessarily required. The field sys_pinnable_frames provides this information, however, this value and other statistical values are just approximations. They reflect the state of the system at the time of the request. They are not updated during the request. The current size of physical memory can be determined by referencing the _system_configuration.physmem field.
To provide support for virtual real memory related DR operations, a new field, dr_op, has been added to the dr_info structure. The dr_op field provides information about the current DR operation. Additionally, all future DR operations use this field and the previously used resource bits will no longer be extended.
dr_wlm_info Structure
typedef struct dr_wlm_info {
unsigned int cpu_add : 1; // cpu wlm resource add for the WPAR
unsigned int cpu_rem : 1; // cpu wlm resource remove for the WPAR
unsigned int mem_add : 1; // memory wlm resource add for the WPAR
unsigned int mem_rem : 1; // memory wlm resource remove for the WPAR
unsigned int rs_cpu : 1; // wlm cpu rset change for the WPAR
unsigned int rs_mem : 1; // wlm memory rset change for the WPAR
unsigned int pad1 : 2; // un-used
unsigned int cpu_cap : 8; // percentage of cpu capacity of the WPAR
unsigned int mem_cap : 8; // percentage of the memory capacity of the WPAR
unsigned int pad2 : 8; // un-used
} dr_wlm_info_t;dr_info Structure
typedef struct dr_info {
unsigned int add : 1; // add request
rem : 1; // remove request
cpu : 1; // target resource is a cpu
mem : 1; // target resource is memory
check : 1; // check phase in effect
pre : 1; // pre phase in effect
post : 1; // post phase in effect
posterror : 1; // post error phase in effect
force : 1; // force option is in effect
bindproc : 1; // process has bindprocessor dependency
softpset : 1; // process has WLM software partition dependency
hardpset : 1; // process has processor set API dependency
plock : 1; // process has plock'd memory
pshm : 1; // process has pinned shared memory
ent_cap : 1; // target resource:entitled capacity
var_wgt : 1; // target resource:variable weight
splpar_capable : 1; // 1/0 partition is/not splpar capable
splpar_shared : 1; // 1/0 partition shared/dedicated mode
splpar_capped : 1; // 1/0 partition capped/uncapped mode
splpar_constrained : 1; // Set to 1 if requested capacity
update is constrained by PHYP to
be within partition capacity bounds.
//
unsigned int migrate : 1; // migration operation
unsigned int hibernate : 1; // hibernation operation
unsigned int partition : 1; // resource is partition
unsigned int topology_update : 1; // topology update
// The following fields are filled out for cpu based requests
int lcpu; // logical cpu ID being added or removed
int bcpu; // bind cpu ID being added or removed
// The following fields are filled out for memory based requests
size64_t req_memsz_change; // User request size in bytes
size64_t sys_memsz; // System Memory size at time of request
rpn64_t sys_free_frames; // Number of free frames in the system
rpn64_t sys_pinnable_frames; // Number of pinnable frames in system
rpn64_t sys_total_frames; // Total number of frames in system
// SPLPAR parameters.
uint64_t capacity; // partition current entitled capacity
if ent_cap bit is set, partition's
current variable capacity weight
if var_wgt bit is set.
//
int delta_cap; // delta capacity added/removed to
current value depending on add/rem
bit flag value above
//
dr_wlm_info_t dr_wlm; // DR info for the WPAR
ushort dr_op; // type of DR operation
ushort dr_pad; // reserved pad field
size64_t mem_capacity; // partition’s entitled
I/O memory or variable capacity.
ssize64_t delta_mem_capacity; // amount of I/O being added/removed
int reserved[2];
} dr_info_t;| Item | Description |
|---|---|
| flags | The following values are supported:
|
| dr_info | Contains the address of a dr_info structure, which is declared with the address space of the application. |
Upon success, the dr_reconfig system call returns a zero. If unsuccessful, it returns negative one and sets the errno variable to the appropriate error value.
| Item | Description |
|---|---|
| EINVAL | Invalid flags. |
| ENXIO | No DLPAR event in progress. |
| EPERM | Root authority required for DR_EVENT_FAIL. |
| EINPROGRESS | Cancellation of DLPAR event may only occur in the check phase. |