On Fri, Jun 21, 2013 at 11:44 AM, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Fri, Jun 21, 2013 at 11:36:21AM -0700, Yinghai Lu wrote: >> On Fri, Jun 21, 2013 at 9:25 AM, Nathan Zimmer <nzimmer@xxxxxxx> wrote: >> > This rfc patch set delays initializing large sections of memory until we have >> > started cpus. This has the effect of reducing startup times on large memory >> > systems. On 16TB it can take over an hour to boot and most of that time >> > is spent initializing memory. >> >> One hour on system with 16T ram? BIOS or OS? >> >> I use wall clock to check bootime on one system with 3T and 16 pcie cards, >> Linus only takes about 3m and 30 seconds from bootloader. >> >> wonder if you boot delay is with so many cpu get onlined in serialized mode. >> >> so can you try boot your system with "maxcpus=128" to get the boot time with >> wall clock ? > > Why use the "wall clock" when we have the wonderful bootchart tools and > scripts that do this all for you, and can tell you exactly what part of > the kernel is taking what time, to help with fixing issues like this? bootchart is not completed. printk timestamp come after mem get initialized. .... [ 0.004000] tsc: Fast TSC calibration using PIT before that stamp are all 0. Yinghai -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
