On 6/21/2013 12:00 PM, Yinghai Lu wrote: > On Fri, Jun 21, 2013 at 11:44 AM, Greg Kroah-Hartman > <gre...@linuxfoundation.org> 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 <nzim...@sgi.com> 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 >
On UV the system console function has an option to include timestamps, both sequential in HH:MM:SS and deltas to 100ms. So we get both the BIOS and system times before printk time is active. We also have a custom "script" command that adds timing info. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
