Timing Elements

SimSANs defines 25 timing elements for Host/CHIP CPU (9), FC-2 Controller (6), Switch CPU (3), and Device Control Memory CPU (7). Each of them is associated with a program task, in which instructions are decoded and executed by referencing memory spaces and consuming CPU cycles. The following formula is used for timing a task:

TaskTime = INSTR_NUM x (CPU_CYL_INS + MEM_REF_INS x Mem_Clock / CPU_Clock) / (CPU_Clock x 1000000)

TaskTime	: CPU time consuming (second) to fulfill a task
CPU_Clock	: Processor clock in MHz
Mem_Clock	: Memory clock in MHz
INSTR_NUM	: Number of processor instructions to fulfill the task
CPU_CYL_INS	: Number of processor cycles for decoding and execution of an instruction
MEM_REF_INS	: Number of memory references needed for an instruction

The following table lists all of the 25 tasks as well as the targets they belong to. Note usually each Processor Timing File contains tasks associated with one target but it is possible to include tasks associated with different targets into a single file when multiple targets use the same processor. For example you can setup Pentium_III_733 for both Host and Array and include both targets' timing elements into the same processor's timing file, say, Pentium_III_733.ini. Several sample timing files (MyHostCpu.ini, MyChipCpu.ini, MyFcCtrl.ini, MyArrayCpu.ini, and MySwCpu.ini) are included in the Package for user's reference, of which MyHostCpu.ini also demonstrates how multiple targets use the same processor.

Task Name	Target	Description
FC4_IU_SEND	Node (Host or CHIP)	Issue FC4 IU
FC4_IU_RECV		Receive FC4 IU
FCP_IU_SEND		Issue FCP IU
FCP_IU_RECV		Receive FCP IU
CRE_IT_PATH		Create Initiator-Target Path
RMV_IT_PATH		Remove Initiator-Target Path
INI_SCSI_IO		Initiate SCSI IO
INI_SCSI_SIO		Initiate SCSI SubIO
COM_SCSI_IO		Conclude SCSI IO
FC_SEQ_SEG	FC_Ports	FC Sequence segmentation
FC_FRM_TXU		Sending Frame updates ESB
FC_FRM_RXU		Receiving Frame updates ESB
FC_SEQ_ASM		FC Sequence assembly
FC4_IU_SEND		Issue FC4 IU, for FC-4 Controller in Switch Port
FC4_IU_RECV		Receive FC4 IU, for FC-4 Controller in Switch Port
PER_CCH_IDX	Array	Per-Cache block indexing
COM_PND_BLK		Complete a pending block and request/update Cache space
SCSI_WR_SEG		WRITE IO segmentation
SCSI_RD_SEG		READ IO segmentation
RMV_LUN_IO		Remove LUN IO due to IT_Path unavailable
COM_BLK_WR		Complete block write and update the Cache
COM_BLK_RD		Complete block read and update the Cache
FRM_FWD	Switch	Lookup routing table and forward Frames
NS_ZONE		Naming and Zoning services
RT_BULD		Path selection and routing table building