linux/init
Jack Steiner b565201cf7 x86: Reduce clock calibration time during slave cpu startup
Reduce the startup time for slave cpus.

Adds hooks for an arch-specific function for clock calibration.
These hooks are used on x86.  If a newly started cpu has the
same phys_proc_id as a core already active, uses the TSC for the
delay loop and has a CONSTANT_TSC, use the already-calculated
value of loops_per_jiffy.

This patch reduces the time required to start slave cpus on a
4096 cpu system from: 465 sec OLD 62 sec NEW

This reduces boot time on a 4096p system by almost 7 minutes.
Nice...

Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: John Stultz <john.stultz@linaro.org>
[fix CONFIG_SMP=n build]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-05 17:12:43 +01:00
..
calibrate.c x86: Reduce clock calibration time during slave cpu startup 2011-12-05 17:12:43 +01:00
do_mounts_initrd.c Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
do_mounts_md.c init: mark __user address space on string literals 2010-10-26 16:52:15 -07:00
do_mounts_rd.c init/do_mounts_rd.c: fix ramdisk identification for padded cramfs 2011-11-02 16:06:58 -07:00
do_mounts.c init: add root=PARTUUID=UUID/PARTNROFF=%d support 2011-11-02 16:07:01 -07:00
do_mounts.h md: move lots of #include lines out of .h files and into .c 2009-03-31 14:33:13 +11:00
initramfs.c Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 15:13:55 -07:00
Kconfig sysctl: make CONFIG_SYSCTL_SYSCALL default to n 2011-11-02 16:07:02 -07:00
main.c Merge branch 'upstream/jump-label-noearly' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2011-11-06 20:20:46 -08:00
Makefile kbuild: move compile.h to include/generated 2009-12-12 13:08:14 +01:00
noinitramfs.c init: mark __user address space on string literals 2010-10-26 16:52:15 -07:00
version.c userns: add a user_namespace as creator/owner of uts_namespace 2011-03-23 19:46:59 -07:00