NetBSD/sys/dev/raidframe/rf_aselect.c

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2002-08-02 04:24:56 +04:00
/* $NetBSD: rf_aselect.c,v 1.6 2002/08/02 00:24:56 oster Exp $ */
/*
* Copyright (c) 1995 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Mark Holland, William V. Courtright II
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*****************************************************************************
*
* aselect.c -- algorithm selection code
*
*****************************************************************************/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: rf_aselect.c,v 1.6 2002/08/02 00:24:56 oster Exp $");
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#include <dev/raidframe/raidframevar.h>
#include "rf_archs.h"
#include "rf_raid.h"
#include "rf_dag.h"
#include "rf_dagutils.h"
#include "rf_dagfuncs.h"
#include "rf_general.h"
#include "rf_desc.h"
#include "rf_map.h"
#if defined(__NetBSD__) && defined(_KERNEL)
/* the function below is not used... so don't define it! */
#else
static void TransferDagMemory(RF_DagHeader_t *, RF_DagHeader_t *);
#endif
static int InitHdrNode(RF_DagHeader_t **, RF_Raid_t *, int);
static void UpdateNodeHdrPtr(RF_DagHeader_t *, RF_DagNode_t *);
int rf_SelectAlgorithm(RF_RaidAccessDesc_t *, RF_RaidAccessFlags_t);
/******************************************************************************
*
* Create and Initialiaze a dag header and termination node
*
*****************************************************************************/
static int
InitHdrNode(hdr, raidPtr, memChunkEnable)
RF_DagHeader_t **hdr;
RF_Raid_t *raidPtr;
int memChunkEnable;
{
/* create and initialize dag hdr */
*hdr = rf_AllocDAGHeader();
rf_MakeAllocList((*hdr)->allocList);
if ((*hdr)->allocList == NULL) {
rf_FreeDAGHeader(*hdr);
return (ENOMEM);
}
(*hdr)->status = rf_enable;
(*hdr)->numSuccedents = 0;
(*hdr)->raidPtr = raidPtr;
(*hdr)->next = NULL;
return (0);
}
/*****************************************************************************************
*
* Ensure that all node->dagHdr fields in a dag are consistent
*
* IMPORTANT: This routine recursively searches all succedents of the node. If a
* succedent is encountered whose dagHdr ptr does not require adjusting, that node's
* succedents WILL NOT BE EXAMINED.
*
****************************************************************************************/
static void
UpdateNodeHdrPtr(hdr, node)
RF_DagHeader_t *hdr;
RF_DagNode_t *node;
{
int i;
RF_ASSERT(hdr != NULL && node != NULL);
for (i = 0; i < node->numSuccedents; i++)
if (node->succedents[i]->dagHdr != hdr)
UpdateNodeHdrPtr(hdr, node->succedents[i]);
node->dagHdr = hdr;
}
/******************************************************************************
*
* Create a DAG to do a read or write operation.
*
* create an array of dagLists, one list per parity stripe.
* return the lists in the array desc->dagArray.
*
* Normally, each list contains one dag for the entire stripe. In some
* tricky cases, we break this into multiple dags, either one per stripe
* unit or one per block (sector). When this occurs, these dags are returned
* as a linked list (dagList) which is executed sequentially (to preserve
* atomic parity updates in the stripe).
*
* dags which operate on independent parity goups (stripes) are returned in
* independent dagLists (distinct elements in desc->dagArray) and may be
* executed concurrently.
*
* Finally, if the SelectionFunc fails to create a dag for a block, we punt
* and return 1.
*
* The above process is performed in two phases:
* 1) create an array(s) of creation functions (eg stripeFuncs)
* 2) create dags and concatenate/merge to form the final dag.
*
* Because dag's are basic blocks (single entry, single exit, unconditional
* control flow, we can add the following optimizations (future work):
* first-pass optimizer to allow max concurrency (need all data dependencies)
* second-pass optimizer to eliminate common subexpressions (need true
* data dependencies)
* third-pass optimizer to eliminate dead code (need true data dependencies)
*****************************************************************************/
#define MAXNSTRIPES 50
int
rf_SelectAlgorithm(desc, flags)
RF_RaidAccessDesc_t *desc;
RF_RaidAccessFlags_t flags;
{
RF_AccessStripeMapHeader_t *asm_h = desc->asmap;
RF_IoType_t type = desc->type;
RF_Raid_t *raidPtr = desc->raidPtr;
void *bp = desc->bp;
RF_AccessStripeMap_t *asmap = asm_h->stripeMap;
RF_AccessStripeMap_t *asm_p;
RF_DagHeader_t *dag_h = NULL, *tempdag_h, *lastdag_h;
int i, j, k;
RF_VoidFuncPtr *stripeFuncs, normalStripeFuncs[MAXNSTRIPES];
RF_AccessStripeMap_t *asm_up, *asm_bp;
RF_AccessStripeMapHeader_t ***asmh_u, *endASMList;
RF_AccessStripeMapHeader_t ***asmh_b;
RF_VoidFuncPtr **stripeUnitFuncs, uFunc;
RF_VoidFuncPtr **blockFuncs, bFunc;
int numStripesBailed = 0, cantCreateDAGs = RF_FALSE;
int numStripeUnitsBailed = 0;
int stripeNum, numUnitDags = 0, stripeUnitNum, numBlockDags = 0;
RF_StripeNum_t numStripeUnits;
RF_SectorNum_t numBlocks;
RF_RaidAddr_t address;
int length;
RF_PhysDiskAddr_t *physPtr;
caddr_t buffer;
lastdag_h = NULL;
asmh_u = asmh_b = NULL;
stripeUnitFuncs = NULL;
blockFuncs = NULL;
/* get an array of dag-function creation pointers, try to avoid
* calling malloc */
if (asm_h->numStripes <= MAXNSTRIPES)
stripeFuncs = normalStripeFuncs;
else
RF_Calloc(stripeFuncs, asm_h->numStripes, sizeof(RF_VoidFuncPtr), (RF_VoidFuncPtr *));
/* walk through the asm list once collecting information */
/* attempt to find a single creation function for each stripe */
desc->numStripes = 0;
for (i = 0, asm_p = asmap; asm_p; asm_p = asm_p->next, i++) {
desc->numStripes++;
(raidPtr->Layout.map->SelectionFunc) (raidPtr, type, asm_p, &stripeFuncs[i]);
/* check to see if we found a creation func for this stripe */
if (stripeFuncs[i] == (RF_VoidFuncPtr) NULL) {
/* could not find creation function for entire stripe
* so, let's see if we can find one for each stripe
* unit in the stripe */
if (numStripesBailed == 0) {
/* one stripe map header for each stripe we
* bail on */
RF_Malloc(asmh_u, sizeof(RF_AccessStripeMapHeader_t **) * asm_h->numStripes, (RF_AccessStripeMapHeader_t ***));
/* create an array of ptrs to arrays of
* stripeFuncs */
RF_Calloc(stripeUnitFuncs, asm_h->numStripes, sizeof(RF_VoidFuncPtr), (RF_VoidFuncPtr **));
}
/* create an array of creation funcs (called
* stripeFuncs) for this stripe */
numStripeUnits = asm_p->numStripeUnitsAccessed;
RF_Calloc(stripeUnitFuncs[numStripesBailed], numStripeUnits, sizeof(RF_VoidFuncPtr), (RF_VoidFuncPtr *));
RF_Malloc(asmh_u[numStripesBailed], numStripeUnits * sizeof(RF_AccessStripeMapHeader_t *), (RF_AccessStripeMapHeader_t **));
/* lookup array of stripeUnitFuncs for this stripe */
for (j = 0, physPtr = asm_p->physInfo; physPtr; physPtr = physPtr->next, j++) {
/* remap for series of single stripe-unit
* accesses */
address = physPtr->raidAddress;
length = physPtr->numSector;
buffer = physPtr->bufPtr;
asmh_u[numStripesBailed][j] = rf_MapAccess(raidPtr, address, length, buffer, RF_DONT_REMAP);
asm_up = asmh_u[numStripesBailed][j]->stripeMap;
/* get the creation func for this stripe unit */
(raidPtr->Layout.map->SelectionFunc) (raidPtr, type, asm_up, &(stripeUnitFuncs[numStripesBailed][j]));
/* check to see if we found a creation func
* for this stripe unit */
if (stripeUnitFuncs[numStripesBailed][j] == (RF_VoidFuncPtr) NULL) {
/* could not find creation function
* for stripe unit so, let's see if we
* can find one for each block in the
* stripe unit */
if (numStripeUnitsBailed == 0) {
/* one stripe map header for
* each stripe unit we bail on */
RF_Malloc(asmh_b, sizeof(RF_AccessStripeMapHeader_t **) * asm_h->numStripes * raidPtr->Layout.numDataCol, (RF_AccessStripeMapHeader_t ***));
/* create an array of ptrs to
* arrays of blockFuncs */
RF_Calloc(blockFuncs, asm_h->numStripes * raidPtr->Layout.numDataCol, sizeof(RF_VoidFuncPtr), (RF_VoidFuncPtr **));
}
/* create an array of creation funcs
* (called blockFuncs) for this stripe
* unit */
numBlocks = physPtr->numSector;
numBlockDags += numBlocks;
RF_Calloc(blockFuncs[numStripeUnitsBailed], numBlocks, sizeof(RF_VoidFuncPtr), (RF_VoidFuncPtr *));
RF_Malloc(asmh_b[numStripeUnitsBailed], numBlocks * sizeof(RF_AccessStripeMapHeader_t *), (RF_AccessStripeMapHeader_t **));
/* lookup array of blockFuncs for this
* stripe unit */
for (k = 0; k < numBlocks; k++) {
/* remap for series of single
* stripe-unit accesses */
address = physPtr->raidAddress + k;
length = 1;
buffer = physPtr->bufPtr + (k * (1 << raidPtr->logBytesPerSector));
asmh_b[numStripeUnitsBailed][k] = rf_MapAccess(raidPtr, address, length, buffer, RF_DONT_REMAP);
asm_bp = asmh_b[numStripeUnitsBailed][k]->stripeMap;
/* get the creation func for
* this stripe unit */
(raidPtr->Layout.map->SelectionFunc) (raidPtr, type, asm_bp, &(blockFuncs[numStripeUnitsBailed][k]));
/* check to see if we found a
* creation func for this
* stripe unit */
if (blockFuncs[numStripeUnitsBailed][k] == NULL)
cantCreateDAGs = RF_TRUE;
}
numStripeUnitsBailed++;
} else {
numUnitDags++;
}
}
RF_ASSERT(j == numStripeUnits);
numStripesBailed++;
}
}
if (cantCreateDAGs) {
/* free memory and punt */
if (asm_h->numStripes > MAXNSTRIPES)
RF_Free(stripeFuncs, asm_h->numStripes * sizeof(RF_VoidFuncPtr));
if (numStripesBailed > 0) {
stripeNum = 0;
for (i = 0, asm_p = asmap; asm_p; asm_p = asm_p->next, i++)
if (stripeFuncs[i] == NULL) {
numStripeUnits = asm_p->numStripeUnitsAccessed;
for (j = 0; j < numStripeUnits; j++)
rf_FreeAccessStripeMap(asmh_u[stripeNum][j]);
RF_Free(asmh_u[stripeNum], numStripeUnits * sizeof(RF_AccessStripeMapHeader_t *));
RF_Free(stripeUnitFuncs[stripeNum], numStripeUnits * sizeof(RF_VoidFuncPtr));
stripeNum++;
}
RF_ASSERT(stripeNum == numStripesBailed);
RF_Free(stripeUnitFuncs, asm_h->numStripes * sizeof(RF_VoidFuncPtr));
RF_Free(asmh_u, asm_h->numStripes * sizeof(RF_AccessStripeMapHeader_t **));
}
return (1);
} else {
/* begin dag creation */
stripeNum = 0;
stripeUnitNum = 0;
/* create an array of dagLists and fill them in */
RF_CallocAndAdd(desc->dagArray, desc->numStripes, sizeof(RF_DagList_t), (RF_DagList_t *), desc->cleanupList);
for (i = 0, asm_p = asmap; asm_p; asm_p = asm_p->next, i++) {
/* grab dag header for this stripe */
dag_h = NULL;
desc->dagArray[i].desc = desc;
if (stripeFuncs[i] == (RF_VoidFuncPtr) NULL) {
/* use bailout functions for this stripe */
for (j = 0, physPtr = asm_p->physInfo; physPtr; physPtr = physPtr->next, j++) {
uFunc = stripeUnitFuncs[stripeNum][j];
if (uFunc == (RF_VoidFuncPtr) NULL) {
/* use bailout functions for
* this stripe unit */
for (k = 0; k < physPtr->numSector; k++) {
/* create a dag for
* this block */
InitHdrNode(&tempdag_h, raidPtr, rf_useMemChunks);
desc->dagArray[i].numDags++;
if (dag_h == NULL) {
dag_h = tempdag_h;
} else {
lastdag_h->next = tempdag_h;
}
lastdag_h = tempdag_h;
bFunc = blockFuncs[stripeUnitNum][k];
RF_ASSERT(bFunc);
asm_bp = asmh_b[stripeUnitNum][k]->stripeMap;
(*bFunc) (raidPtr, asm_bp, tempdag_h, bp, flags, tempdag_h->allocList);
}
stripeUnitNum++;
} else {
/* create a dag for this unit */
InitHdrNode(&tempdag_h, raidPtr, rf_useMemChunks);
desc->dagArray[i].numDags++;
if (dag_h == NULL) {
dag_h = tempdag_h;
} else {
lastdag_h->next = tempdag_h;
}
lastdag_h = tempdag_h;
asm_up = asmh_u[stripeNum][j]->stripeMap;
(*uFunc) (raidPtr, asm_up, tempdag_h, bp, flags, tempdag_h->allocList);
}
}
RF_ASSERT(j == asm_p->numStripeUnitsAccessed);
/* merge linked bailout dag to existing dag
* collection */
stripeNum++;
} else {
/* Create a dag for this parity stripe */
InitHdrNode(&tempdag_h, raidPtr, rf_useMemChunks);
desc->dagArray[i].numDags++;
if (dag_h == NULL) {
dag_h = tempdag_h;
} else {
lastdag_h->next = tempdag_h;
}
lastdag_h = tempdag_h;
(stripeFuncs[i]) (raidPtr, asm_p, tempdag_h, bp, flags, tempdag_h->allocList);
}
desc->dagArray[i].dags = dag_h;
}
RF_ASSERT(i == desc->numStripes);
/* free memory */
if (asm_h->numStripes > MAXNSTRIPES)
RF_Free(stripeFuncs, asm_h->numStripes * sizeof(RF_VoidFuncPtr));
if ((numStripesBailed > 0) || (numStripeUnitsBailed > 0)) {
stripeNum = 0;
stripeUnitNum = 0;
if (dag_h->asmList) {
endASMList = dag_h->asmList;
while (endASMList->next)
endASMList = endASMList->next;
} else
endASMList = NULL;
/* walk through io, stripe by stripe */
for (i = 0, asm_p = asmap; asm_p; asm_p = asm_p->next, i++)
if (stripeFuncs[i] == NULL) {
numStripeUnits = asm_p->numStripeUnitsAccessed;
/* walk through stripe, stripe unit by
* stripe unit */
for (j = 0, physPtr = asm_p->physInfo; physPtr; physPtr = physPtr->next, j++) {
if (stripeUnitFuncs[stripeNum][j] == NULL) {
numBlocks = physPtr->numSector;
/* walk through stripe
* unit, block by
* block */
for (k = 0; k < numBlocks; k++)
if (dag_h->asmList == NULL) {
dag_h->asmList = asmh_b[stripeUnitNum][k];
endASMList = dag_h->asmList;
} else {
endASMList->next = asmh_b[stripeUnitNum][k];
endASMList = endASMList->next;
}
RF_Free(asmh_b[stripeUnitNum], numBlocks * sizeof(RF_AccessStripeMapHeader_t *));
RF_Free(blockFuncs[stripeUnitNum], numBlocks * sizeof(RF_VoidFuncPtr));
stripeUnitNum++;
}
if (dag_h->asmList == NULL) {
dag_h->asmList = asmh_u[stripeNum][j];
endASMList = dag_h->asmList;
} else {
endASMList->next = asmh_u[stripeNum][j];
endASMList = endASMList->next;
}
}
RF_Free(asmh_u[stripeNum], numStripeUnits * sizeof(RF_AccessStripeMapHeader_t *));
RF_Free(stripeUnitFuncs[stripeNum], numStripeUnits * sizeof(RF_VoidFuncPtr));
stripeNum++;
}
RF_ASSERT(stripeNum == numStripesBailed);
RF_Free(stripeUnitFuncs, asm_h->numStripes * sizeof(RF_VoidFuncPtr));
RF_Free(asmh_u, asm_h->numStripes * sizeof(RF_AccessStripeMapHeader_t **));
if (numStripeUnitsBailed > 0) {
RF_ASSERT(stripeUnitNum == numStripeUnitsBailed);
RF_Free(blockFuncs, raidPtr->Layout.numDataCol * asm_h->numStripes * sizeof(RF_VoidFuncPtr));
RF_Free(asmh_b, raidPtr->Layout.numDataCol * asm_h->numStripes * sizeof(RF_AccessStripeMapHeader_t **));
}
}
return (0);
}
}