On Thursday 17 March 2016 10:08:41 Richard W.M. Jones wrote: > The quiet option suppresses kernel messages. On my laptop it improves > appliance boot times by about 40% (3.5s -> 2.5s). > > The emulated UART is slow and has a fixed, small FIFO (16 bytes). But > it has the advantage of being a simple ISA device which is available > very early in boot, thus enabling us to diagnose early boot problems. > So the aim is to reduce our usage of this UART on fast paths. > > Of course when we are in verbose mode, we should not add this flag > because we want to see all the messages. > > This change is not entirely invisible: > > (1) Progress messages use the "Linux version ..." string from kernel > output in order to determine part of where we are in the boot process. > This string will no longer be detected. We should probably use a BIOS > message or maybe drop this altogether. I have added a comment to the > code. > > (2) It is possible for programs to be listening for > GUESTFS_EVENT_APPLIANCE events, and they will see fewer messages now > (although what kernel messages programs see is never defined).
From what I see, these events were sent only after 5 seconds from the launch, so users of the library should (theoretically of course) be already prepared to not receive them. I guess that this could be mentioned in the commit message. -- Pino Toscano
signature.asc
Description: This is a digitally signed message part.
_______________________________________________ Libguestfs mailing list [email protected] https://www.redhat.com/mailman/listinfo/libguestfs
