From 72f8a321e9aa080c872742a6e2e5092b9fa5b37e Mon Sep 17 00:00:00 2001
From: Yifan Sun <sunyifan112358@gmail.com>
Date: Sat, 20 Apr 2019 00:10:48 -0400
Subject: [PATCH] Bug fix
---
cache/writeback/bankstage.go | 10 ++---
cache/writeback/bankstage_test.go | 4 --
cache/writeback/bottomparser.go | 21 ++++++++-
cache/writeback/bottomparser_test.go | 3 ++
cache/writeback/directorystage.go | 60 ++++++++++++++++++--------
cache/writeback/directorystage_test.go | 46 +++++++++++++-------
cache/writeback/mshrstage.go | 4 +-
cache/writeback/trace.go | 30 +++++++------
cache/writeback/transaction.go | 16 ++++---
cache/writeback/writebackcache.go | 18 ++++----
10 files changed, 138 insertions(+), 74 deletions(-)
diff --git a/cache/writeback/bankstage.go b/cache/writeback/bankstage.go
index b3d7a35..7d5fdc7 100644
--- a/cache/writeback/bankstage.go
+++ b/cache/writeback/bankstage.go
@@ -20,7 +20,6 @@ type bankStage struct {
mshrStageBuffer util.Buffer
inFlightTransactions *[]*transaction
- pendingEvictions *[]*transaction
cycleLeft int
currentTrans *transaction
@@ -87,7 +86,7 @@ func (s *bankStage) finalizeReadHit(now akita.VTimeInSec) bool {
dataReady.Data = data
s.topSender.Send(dataReady)
- trace("read done", addr, dataReady.Data)
+ trace(now, "read hit done", addr, dataReady.Data)
return true
}
@@ -124,7 +123,7 @@ func (s *bankStage) finalizeWriteHit(now akita.VTimeInSec) bool {
done := mem.NewDoneRsp(now, s.topPort, write.Src(), write.ID)
s.topSender.Send(done)
- trace("write done", addr, write.Data)
+ trace(now, "write hit done", addr, write.Data)
return true
}
@@ -142,7 +141,7 @@ func (s *bankStage) finalizeBankWriteFetched(now akita.VTimeInSec) bool {
block.IsLocked = false
block.IsValid = true
- trace("write fetched", block.Tag, mshrEntry.Data)
+ trace(now, "write fetched", block.Tag, mshrEntry.Data)
s.currentTrans = nil
@@ -178,10 +177,11 @@ func (s *bankStage) finalizeBankReadForEviction(now akita.VTimeInSec) bool {
write.Data = data
write.DirtyMask = victim.DirtyMask
trans.eviction = write
- *s.pendingEvictions = append(*s.pendingEvictions, trans)
s.bottomSender.Send(write)
s.currentTrans = nil
+ trace(now, "evict", victim.Tag, data)
+
return true
}
diff --git a/cache/writeback/bankstage_test.go b/cache/writeback/bankstage_test.go
index 2c1e2de..59a1388 100644
--- a/cache/writeback/bankstage_test.go
+++ b/cache/writeback/bankstage_test.go
@@ -18,7 +18,6 @@ var _ = Describe("Bank Stage", func() {
bottomSender *MockBufferedSender
mshrStageBuffer *MockBuffer
lowModuleFinder *MockLowModuleFinder
- pendingEvictions []*transaction
inFlightTransactions []*transaction
)
@@ -30,7 +29,6 @@ var _ = Describe("Bank Stage", func() {
bottomSender = NewMockBufferedSender(mockCtrl)
lowModuleFinder = NewMockLowModuleFinder(mockCtrl)
storage = mem.NewStorage(4 * mem.KB)
- pendingEvictions = nil
inFlightTransactions = nil
bs = &bankStage{
@@ -42,7 +40,6 @@ var _ = Describe("Bank Stage", func() {
bottomSender: bottomSender,
lowModuleFinder: lowModuleFinder,
mshrStageBuffer: mshrStageBuffer,
- pendingEvictions: &pendingEvictions,
inFlightTransactions: &inFlightTransactions,
}
})
@@ -322,7 +319,6 @@ var _ = Describe("Bank Stage", func() {
ret := bs.Tick(10)
Expect(ret).To(BeTrue())
Expect(trans.eviction).To(BeIdenticalTo(evictionReq))
- Expect(pendingEvictions).To(ContainElement(trans))
Expect(bs.currentTrans).To(BeNil())
})
diff --git a/cache/writeback/bottomparser.go b/cache/writeback/bottomparser.go
index 9e4b684..c092c6f 100644
--- a/cache/writeback/bottomparser.go
+++ b/cache/writeback/bottomparser.go
@@ -54,7 +54,7 @@ func (p *bottomParser) handleDataReady(
return false
}
- trace("data ready", block.Tag, dr.Data)
+ trace(now, "data ready", block.Tag, dr.Data)
p.port.Retrieve(now)
@@ -110,6 +110,7 @@ func (p *bottomParser) handleDoneRsp(
}
trans := p.findEvictionTrans(done)
+ trans.evictionDone = done
if trans.mshrEntry != nil {
return p.fetch(now, trans)
}
@@ -137,6 +138,17 @@ func (p *bottomParser) findEvictionTrans(done *mem.DoneRsp) *transaction {
panic("pending eviction not found")
}
+func (p *bottomParser) removeEvictionTrans(done *mem.DoneRsp) {
+ for i, t := range *p.pendingEvictions {
+ if t.eviction.ID == done.RespondTo {
+ *p.pendingEvictions = append((*p.pendingEvictions)[:i],
+ (*p.pendingEvictions)[i+1:]...)
+ return
+ }
+ }
+ panic("pending eviction not found")
+}
+
func (p *bottomParser) fetch(now akita.VTimeInSec, trans *transaction) bool {
if !p.bottomSender.CanSend(1) {
return false
@@ -157,6 +169,10 @@ func (p *bottomParser) fetch(now akita.VTimeInSec, trans *transaction) bool {
p.bottomSender.Send(read)
p.port.Retrieve(now)
+ p.removeEvictionTrans(trans.evictionDone)
+
+ trace(now, "fetch (bottomParser)", read.Address, nil)
+
return true
}
@@ -173,5 +189,8 @@ func (p *bottomParser) writeBank(
trans.bankAction = bankWriteHit
bankBuf.Push(trans)
p.port.Retrieve(now)
+
+ p.removeEvictionTrans(trans.evictionDone)
+
return true
}
diff --git a/cache/writeback/bottomparser_test.go b/cache/writeback/bottomparser_test.go
index d3d320a..4a6f9a8 100644
--- a/cache/writeback/bottomparser_test.go
+++ b/cache/writeback/bottomparser_test.go
@@ -33,6 +33,7 @@ var _ = Describe("Bottom Parser", func() {
lowModuleFinder = NewMockLowModuleFinder(mockCtrl)
flusherBuffer = NewMockBuffer(mockCtrl)
state = cacheStateRunning
+ pendingEvictions = nil
parser = &bottomParser{
port: port,
@@ -192,6 +193,7 @@ var _ = Describe("Bottom Parser", func() {
Expect(ret).To(BeTrue())
Expect(mshrEntry.ReadReq).To(BeIdenticalTo(readReq))
+ Expect(pendingEvictions).To(HaveLen(0))
})
})
@@ -247,6 +249,7 @@ var _ = Describe("Bottom Parser", func() {
Expect(ret).To(BeTrue())
Expect(evictionTrans.bankAction).To(Equal(bankWriteHit))
+ Expect(pendingEvictions).To(HaveLen(0))
})
})
diff --git a/cache/writeback/directorystage.go b/cache/writeback/directorystage.go
index 0c30f80..1d18c7e 100644
--- a/cache/writeback/directorystage.go
+++ b/cache/writeback/directorystage.go
@@ -8,14 +8,15 @@ import (
)
type directoryStage struct {
- inBuf util.Buffer
- directory cache.Directory
- bankBufs []util.Buffer
- mshr cache.MSHR
- log2BlockSize uint64
- lowModuleFinder cache.LowModuleFinder
- bottomSender util.BufferedSender
- toBottomPort akita.Port
+ inBuf util.Buffer
+ directory cache.Directory
+ bankBufs []util.Buffer
+ mshr cache.MSHR
+ log2BlockSize uint64
+ lowModuleFinder cache.LowModuleFinder
+ bottomSender util.BufferedSender
+ toBottomPort akita.Port
+ pendingEvictions *[]*transaction
}
func (ds *directoryStage) Tick(now akita.VTimeInSec) bool {
@@ -35,7 +36,7 @@ func (ds *directoryStage) doRead(
now akita.VTimeInSec,
trans *transaction,
) bool {
- trace("read start", trans.read.Address, nil)
+ trace(now, "read start", trans.read.Address, nil)
cachelineID, _ := GetCacheLineID(
trans.read.Address, ds.log2BlockSize)
block := ds.directory.Lookup(cachelineID)
@@ -79,7 +80,7 @@ func (ds *directoryStage) handleReadMiss(
victim := ds.directory.FindVictim(cacheLineID)
if ds.needEviction(victim) {
- return ds.evict(trans, victim)
+ return ds.evict(now, trans, victim)
}
return ds.fetch(now, trans, victim)
@@ -90,7 +91,7 @@ func (ds *directoryStage) doWrite(
trans *transaction,
) bool {
write := trans.write
- trace("write start", trans.write.Address, write.Data)
+ trace(now, "write start", trans.write.Address, write.Data)
cachelineID, _ := GetCacheLineID(write.Address, ds.log2BlockSize)
block := ds.directory.Lookup(cachelineID)
@@ -126,12 +127,12 @@ func (ds *directoryStage) doWriteMiss(
}
if ds.isWritingFullLine(write) {
- return ds.writeFullLineMiss(trans)
+ return ds.writeFullLineMiss(now, trans)
}
return ds.writePartialLineMiss(now, trans)
}
-func (ds *directoryStage) writeFullLineMiss(trans *transaction) bool {
+func (ds *directoryStage) writeFullLineMiss(now akita.VTimeInSec, trans *transaction) bool {
write := trans.write
cachelineID, _ := GetCacheLineID(write.Address, ds.log2BlockSize)
@@ -141,7 +142,7 @@ func (ds *directoryStage) writeFullLineMiss(trans *transaction) bool {
}
if ds.needEviction(victim) {
- return ds.evict(trans, victim)
+ return ds.evict(now, trans, victim)
}
return ds.writeToBank(trans, victim)
@@ -164,7 +165,7 @@ func (ds *directoryStage) writePartialLineMiss(
}
if ds.needEviction(victim) {
- return ds.evict(trans, victim)
+ return ds.evict(now, trans, victim)
}
return ds.fetch(now, trans, victim)
@@ -219,6 +220,7 @@ func (ds *directoryStage) writeToBank(
}
func (ds *directoryStage) evict(
+ now akita.VTimeInSec,
trans *transaction,
victim *cache.Block,
) bool {
@@ -261,6 +263,11 @@ func (ds *directoryStage) evict(
ds.inBuf.Pop()
bankBuf.Push(trans)
+ trans.evictingAddr = trans.victim.Tag
+ *ds.pendingEvictions = append(*ds.pendingEvictions, trans)
+
+ trace(now, "evict (dir)", trans.victim.Tag, nil)
+
return true
}
@@ -269,9 +276,6 @@ func (ds *directoryStage) fetch(
trans *transaction,
block *cache.Block,
) bool {
- if !ds.bottomSender.CanSend(1) {
- return false
- }
var addr uint64
if trans.read != nil {
@@ -279,10 +283,17 @@ func (ds *directoryStage) fetch(
} else {
addr = trans.write.Address
}
-
cacheLineID, _ := GetCacheLineID(
addr, uint64(ds.log2BlockSize))
+ if ds.isEvicting(cacheLineID) {
+ return false
+ }
+
+ if !ds.bottomSender.CanSend(1) {
+ return false
+ }
+
mshrEntry := ds.mshr.Add(cacheLineID)
trans.mshrEntry = mshrEntry
trans.block = block
@@ -302,6 +313,8 @@ func (ds *directoryStage) fetch(
)
ds.bottomSender.Send(read)
+ trace(now, "fetch (dir)", read.Address, nil)
+
mshrEntry.ReadReq = read
mshrEntry.Requests = append(mshrEntry.Requests, trans)
mshrEntry.Block = block
@@ -309,6 +322,15 @@ func (ds *directoryStage) fetch(
return true
}
+func (ds *directoryStage) isEvicting(addr uint64) bool {
+ for _, t := range *ds.pendingEvictions {
+ if t.evictingAddr == addr {
+ return true
+ }
+ }
+ return false
+}
+
func (ds *directoryStage) isWritingFullLine(write *mem.WriteReq) bool {
return len(write.Data) == (1 << ds.log2BlockSize)
}
diff --git a/cache/writeback/directorystage_test.go b/cache/writeback/directorystage_test.go
index 667d8b5..b4a7dc1 100644
--- a/cache/writeback/directorystage_test.go
+++ b/cache/writeback/directorystage_test.go
@@ -13,14 +13,15 @@ import (
var _ = Describe("DirectoryStage", func() {
var (
- mockCtrl *gomock.Controller
- ds *directoryStage
- mshr *MockMSHR
- dirBuf *MockBuffer
- directory *MockDirectory
- bankBufs []*MockBuffer
- bottomSender *MockBufferedSender
- lowModuleFinder *MockLowModuleFinder
+ mockCtrl *gomock.Controller
+ ds *directoryStage
+ mshr *MockMSHR
+ dirBuf *MockBuffer
+ directory *MockDirectory
+ bankBufs []*MockBuffer
+ bottomSender *MockBufferedSender
+ lowModuleFinder *MockLowModuleFinder
+ pendingEvictions []*transaction
)
BeforeEach(func() {
@@ -33,15 +34,17 @@ var _ = Describe("DirectoryStage", func() {
bankBufs = append(bankBufs, NewMockBuffer(mockCtrl))
bankBufs = append(bankBufs, NewMockBuffer(mockCtrl))
lowModuleFinder = NewMockLowModuleFinder(mockCtrl)
+ pendingEvictions = nil
ds = &directoryStage{
- log2BlockSize: 6,
- inBuf: dirBuf,
- directory: directory,
- mshr: mshr,
- bankBufs: []util.Buffer{bankBufs[0], bankBufs[1]},
- bottomSender: bottomSender,
- lowModuleFinder: lowModuleFinder,
+ log2BlockSize: 6,
+ inBuf: dirBuf,
+ directory: directory,
+ mshr: mshr,
+ bankBufs: []util.Buffer{bankBufs[0], bankBufs[1]},
+ bottomSender: bottomSender,
+ lowModuleFinder: lowModuleFinder,
+ pendingEvictions: &pendingEvictions,
}
})
@@ -175,6 +178,17 @@ var _ = Describe("DirectoryStage", func() {
Expect(ret).To(BeFalse())
})
+ It("should not fetch if it is being evicting", func() {
+ trans := &transaction{
+ evictingAddr: 0x100,
+ }
+ pendingEvictions = append(pendingEvictions, trans)
+
+ ret := ds.Tick(10)
+
+ Expect(ret).To(BeFalse())
+ })
+
It("should create mshr entry and read from bottom", func() {
mshrEntry := &cache.MSHREntry{}
var readBottom *mem.ReadReq
@@ -272,6 +286,8 @@ var _ = Describe("DirectoryStage", func() {
true, true, true, true, false, false, false, false,
true, true, true, true, false, false, false, false,
}))
+ Expect(trans.evictingAddr).To(Equal(uint64(0x200)))
+ Expect(pendingEvictions).To(ContainElement(trans))
Expect(mshrEntry.Block).To(BeIdenticalTo(block))
Expect(mshrEntry.Requests).To(ContainElement(trans))
})
diff --git a/cache/writeback/mshrstage.go b/cache/writeback/mshrstage.go
index ec0c13d..5959691 100644
--- a/cache/writeback/mshrstage.go
+++ b/cache/writeback/mshrstage.go
@@ -62,7 +62,7 @@ func (s *mshrStage) respondRead(
dataReady.Data = data[offset : offset+read.MemByteSize]
s.topSender.Send(dataReady)
- trace("read done", read.Address, dataReady.Data)
+ trace(now, "read done", read.Address, dataReady.Data)
}
func (s *mshrStage) respondWrite(
@@ -72,7 +72,7 @@ func (s *mshrStage) respondWrite(
done := mem.NewDoneRsp(now, s.topPort, write.Src(), write.ID)
s.topSender.Send(done)
- trace("write done", write.Address, write.Data)
+ trace(now, "write done", write.Address, write.Data)
}
func (s *mshrStage) removeTransaction(trans *transaction) {
diff --git a/cache/writeback/trace.go b/cache/writeback/trace.go
index 0df6702..3f55580 100644
--- a/cache/writeback/trace.go
+++ b/cache/writeback/trace.go
@@ -1,15 +1,21 @@
package writeback
-func trace(what string, addr uint64, data []byte) {
- //s := ""
- //s += fmt.Sprintf("%s, 0x%x", what, addr)
- //if data != nil {
- // s += ", ["
- // for _, b := range data {
- // s += fmt.Sprintf("%02x, ", b)
- // }
- // s += "]"
- //}
- //s += "\n"
- //fmt.Print(s)
+import (
+ "fmt"
+
+ "gitlab.com/akita/akita"
+)
+
+func trace(now akita.VTimeInSec, what string, addr uint64, data []byte) {
+ s := ""
+ s += fmt.Sprintf("%.15f, %s, 0x%x", now, what, addr)
+ if data != nil {
+ s += ", ["
+ for _, b := range data {
+ s += fmt.Sprintf("%02x, ", b)
+ }
+ s += "]"
+ }
+ s += "\n"
+ fmt.Print(s)
}
diff --git a/cache/writeback/transaction.go b/cache/writeback/transaction.go
index e90217b..ad1cfaa 100644
--- a/cache/writeback/transaction.go
+++ b/cache/writeback/transaction.go
@@ -14,11 +14,13 @@ const (
)
type transaction struct {
- read *mem.ReadReq
- write *mem.WriteReq
- block *cache.Block
- victim *cache.Block
- eviction *mem.WriteReq
- mshrEntry *cache.MSHREntry
- bankAction bankAction
+ read *mem.ReadReq
+ write *mem.WriteReq
+ block *cache.Block
+ victim *cache.Block
+ evictingAddr uint64
+ eviction *mem.WriteReq
+ evictionDone *mem.DoneRsp
+ mshrEntry *cache.MSHREntry
+ bankAction bankAction
}
diff --git a/cache/writeback/writebackcache.go b/cache/writeback/writebackcache.go
index 1aa4f4b..d6dfd0e 100644
--- a/cache/writeback/writebackcache.go
+++ b/cache/writeback/writebackcache.go
@@ -136,14 +136,15 @@ func NewWriteBackCache(
}
cache.dirStage = &directoryStage{
- inBuf: cache.dirStageBuffer,
- directory: directory,
- mshr: mshr,
- bankBufs: cache.bankBuffers,
- log2BlockSize: defaultLog2BlockSize,
- lowModuleFinder: lowModuleFinder,
- bottomSender: cache.bottomSender,
- toBottomPort: cache.BottomPort,
+ inBuf: cache.dirStageBuffer,
+ directory: directory,
+ mshr: mshr,
+ bankBufs: cache.bankBuffers,
+ log2BlockSize: defaultLog2BlockSize,
+ lowModuleFinder: lowModuleFinder,
+ bottomSender: cache.bottomSender,
+ toBottomPort: cache.BottomPort,
+ pendingEvictions: &cache.pendingEvictions,
}
cache.bankStages = make([]*bankStage, 1)
@@ -158,7 +159,6 @@ func NewWriteBackCache(
bottomPort: cache.BottomPort,
lowModuleFinder: lowModuleFinder,
mshrStageBuffer: cache.mshrStageBuffer,
- pendingEvictions: &cache.pendingEvictions,
inFlightTransactions: &cache.inFlightTransactions,
}
--
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