fix mem load cache mode bug

Signed-off-by: hengyoush <hengyoush1@163.com>

exec/mem/mem.go

@@ -19,15 +19,16 @@ package mem
 import (
 	"context"
 	"fmt"
-	"github.com/chaosblade-io/chaosblade-exec-os/exec"
-	"github.com/chaosblade-io/chaosblade-spec-go/log"
 	"io/ioutil"
 	"math"
 	"os"
 	"path"
 	"strconv"
 	"time"
 
+	"github.com/chaosblade-io/chaosblade-exec-os/exec"
+	"github.com/chaosblade-io/chaosblade-spec-go/log"
+
 	"github.com/chaosblade-io/chaosblade-spec-go/spec"
 	"github.com/chaosblade-io/chaosblade-spec-go/util"
 
@@ -209,7 +210,7 @@ func (ce *memExecutor) Exec(uid string, ctx context.Context, model *spec.ExpMode
 		var err error
 		memPercent, err = strconv.Atoi(memPercentStr)
 		if err != nil {
-			log.Errorf(ctx,"`%s`: mem-percent  must be a positive integer", memPercentStr)
+			log.Errorf(ctx, "`%s`: mem-percent  must be a positive integer", memPercentStr)
 			return spec.ResponseFailWithFlags(spec.ParameterIllegal, "mem-percent", memPercentStr, "it must be a positive integer")
 		}
 		if memPercent > 100 || memPercent < 0 {
@@ -264,12 +265,22 @@ func calculateMemSize(ctx context.Context, burnMemMode string, percent, reserve
 
 var dirName = "burnmem_tmpfs"
 
+var tmpfsName = "chaos_burn"
+
 var fileName = "file"
 
 var fileCount = 1
 
 func burnMemWithCache(ctx context.Context, memPercent, memReserve, memRate int, burnMemMode string, includeBufferCache bool, cl spec.Channel) {
-	filePath := path.Join(path.Join(util.GetProgramPath(), dirName), fileName)
+	tmpfsPath := path.Join(util.GetProgramPath(), dirName)
+	filePath := path.Join(tmpfsPath, fileName)
+	// prepare tmpfs
+	cl.Run(ctx, "mkdir", fmt.Sprintf("-p %s", tmpfsPath))
+	cl.Run(ctx, "mount", fmt.Sprintf("-t tmpfs -o size=100%% %s %s", tmpfsName, tmpfsPath))
+
+	if memRate <= 0 {
+		memRate = 100
+	}
 	tick := time.Tick(time.Second)
 	for range tick {
 		_, expectMem, err := calculateMemSize(ctx, burnMemMode, memPercent, memReserve, includeBufferCache)
@@ -281,6 +292,7 @@ func burnMemWithCache(ctx context.Context, memPercent, memReserve, memRate int,
 			if expectMem > int64(memRate) {
 				fillMem = int64(memRate)
 			}
+			log.Debugf(ctx, "burn mem with cache fill memory: %d", fillMem)
 			nFilePath := fmt.Sprintf("%s%d", filePath, fileCount)
 			response := cl.Run(ctx, "dd", fmt.Sprintf("if=/dev/zero of=%s bs=1M count=%d", nFilePath, fillMem))
 			if !response.Success {
@@ -296,7 +308,7 @@ func (ce *memExecutor) start(ctx context.Context, memPercent, memReserve, memRat
 	// adjust process oom_score_adj to avoid being killed
 	if avoidBeingKilled {
 		scoreAdjFile := fmt.Sprintf(processOOMAdj, os.Getpid())
-		if _, err := os.Stat(scoreAdjFile); err == nil || os.IsExist(err)  {
+		if _, err := os.Stat(scoreAdjFile); err == nil || os.IsExist(err) {
 			if err := ioutil.WriteFile(scoreAdjFile, []byte(oomMinAdj), 0644); err != nil {
 				log.Errorf(ctx, "run burn memory by %s mode failed, cannot edit the process oom_score_adj, %v", burnMemMode, err)
 			}
@@ -348,6 +360,11 @@ func (ce *memExecutor) start(ctx context.Context, memPercent, memReserve, memRat
 
 // stop burn mem
 func (ce *memExecutor) stop(ctx context.Context, burnMemMode string) *spec.Response {
-	ctx = context.WithValue(ctx,"bin", BurnMemBin)
-	return exec.Destroy(ctx, ce.channel, "mem load")
+	ctx = context.WithValue(ctx, "bin", BurnMemBin)
+	response := exec.Destroy(ctx, ce.channel, "mem load")
+	// umount tmpfs
+	ce.channel.Run(ctx, "umount", tmpfsName)
+	tmpfsPath := path.Join(util.GetProgramPath(), dirName)
+	ce.channel.Run(ctx, "rm", fmt.Sprintf("-rf %s", tmpfsPath))
+	return response
 }