Sharepoint log memory allocation stack trace

Use this command in SP power shell window to switch on stack trace logging in case of an error.
I found it here

Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue
[System.Reflection.Assembly]::LoadFile($Env:CommonProgramFiles+"Microsoft SharedWeb Server Extensions14ISAPIMicrosoft.SharePoint.dll") | out-null

# Get Content Service of the farm
$contentService = [Microsoft.SharePoint.Administration.SPWebService]::ContentService

# Display and change the setting of property "CollectSPRequestAllocationCallStacks"
write-host "Current: " $contentService.CollectSPRequestAllocationCallStacks 
$contentService.CollectSPRequestAllocationCallStacks = $true
$contentService.Update()

write-host "    New: " $contentService.CollectSPRequestAllocationCallStacks