一些 xperf 用法

Start a trace

Boot test
xbootmgr -trace boot -numRuns 3 -resultPath C:\traces -postBootDelay 60 -traceFlags latency+dispatcher -stackWalk Profile+CSwitch+ReadyThread -prepsystem

We can use BIOSPOSTTime.ps1 to calculate BIOS POST time.
Be sure to modify the location of trace file in BIOSPOSTTime.ps1

Standby test
xbootmgr -trace standby -numRuns 3 -resultPath C:\traces -postBootDelay 60 -traceFlags base

Hibernation test
xbootmgr -trace hibernate -numRuns 3 -resultPath C:\traces -postBootDelay 60 -traceFlags base

Shutdown test
xbootmgr -trace shutdown -numRuns 3 -resultPath C:\traces -postBootDelay 60 -traceFlags base

Generate an XML summary

For shutdown test
xperf -i trace.etl -o summary.xml -a shutdown

For hibernation and standby test
xperf -i trace.etl -o summary.xml -a suspend

Show available actions
xperf -a /?

---

BIOSPOSTTime.ps1 (copied from Microsoft Velocity)

Run under powershell.exe

這個 ps1 檔其實就是抓 OSLoader 被執行的那個時間，然後按目前 CPU frequency 來換算回 BIOS POST 真正的時間。在 boot transition 的文章中已經看過整個 boot process 在 BIOS 之後即是 OSLoader，再對照這個可印證。

執行時記得確認 powershell 的權限沒問題，將 local machine 的權限改成 undefined or unrestricted 就可以啦！不過要 administrator 的權限就是了！

## Get_BIOSPOSTTime
##
## Checks Boot Traces to find BIOS POST Time
$outfile = New-Item -type file "C:\Velocity_Results\BIOSPostTime\BIOSPostTime.xml" -force

Add-Content $outfile " "
Add-Content $outfile " "

$search_string="OSLoader"
$processorSpeed = -1

$Boot_Traces=gci boot*.etl -path c:\traces -recurse
foreach ($trace in $Boot_Traces) {
 if ($processorSpeed -eq -1) {
     write-host "Getting Processor Speed..." -noNewLine
            $sysconfig = (xperf -quiet -i $trace.FullName -a sysconfig)
     [decimal]$processorSpeedGhz = $sysconfig[4].substring(16,4)
     [decimal]$processorSpeed = $processorSpeedGhz * 1000000
     write-host " $processorSpeedGhz Ghz ($processorSpeed)"    
 } 
    $search_results=xperf -i $trace.FullName -a dumper -range 0ms 1000ms | select-string $search_string
 [string]$header_line = $search_results[0]
 [string]$result_line = $search_results[1]
 $split_header_line=$header_line.split(',')
 $split_result_line=$result_line.split(',')
    $column_index=0
    foreach ( $column in $split_header_line ) {
        if ($column.contains("OSLoaderStart")) {
           break
        }
        $column_index++
    }
 [decimal]$BIOSPOSTCycles = $split_result_line[$column_index]
    write-host "BIOS POST Cycle: " $BIOSPOSTCycles
    write-host "Processor speed: " $processorSpeed
 [decimal]$BIOSPostTime = ($BIOSPOSTCycles / $processorSpeed)
 $BIOSPostTime = ("{0,6:N3}" -f $BIOSPostTime)
 write-host "Trace: " $trace.Name -noNewLine
    write-host "`tBIOS POST Time (sec): "$BIOSPostTime -foregroundcolor white
 Add-Content $outfile "  $BiosPOSTTime "
}
Add-Content $outfile " "