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 [email protected] "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."
