Re: 8.0 performance issue when running build.sh?

[Thor Lancelot Simon <tls%panix.com@localhost>]

On Fri, Jul 13, 2018 at 09:37:26AM +0200, Martin Husemann wrote:
> 
> Do you happen to know why 
> 
> 	vmstat -e | fgrep "bus_dma bounces"
> 
> shows a > 500 rate e.g. on b45? I never see a single bounce on any of my
> amd64 machines. The build slaves seem to do only a few of them though.

Only the master does much if any disk (actually SSD) I/O.  It must be
either the mpt driver or the scsi subsystem.  At a _guess_, mpt?  I
don't have time to look right now.

This is annoying, but seems unlikely to be the cause of the performance
regression; I don't think the master runs builds any more, does it?  So
it shouldn't be doing much and should have tons of CPU and memory
bandwidth available to move that data.

-- 
  Thor Lancelot Simon	                                     tls%panix.com@localhost
 "The two most common variations translate as follows:
	illegitimi non carborundum = the unlawful are not silicon carbide
	illegitimis non carborundum = the unlawful don't have silicon carbide."