From d68921f9bd148359e6d01c84aaa2e32bfbd82970 Mon Sep 17 00:00:00 2001 From: Len Brown <len.brown@intel.com> Date: Mon, 11 May 2015 17:27:09 -0400 Subject: x86/smp/boot: Add cmdline "cpu_init_udelay=N" to specify cpu_up() delay MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit No change to default behavior. Replace the hard-coded mdelay(10) in cpu_up() with a variable udelay, that is set to a defined default -- rather than a magic number. Add a boot-time override, "cpu_init_udelay=N" Signed-off-by: Len Brown <len.brown@intel.com> Cc: Alan Cox <alan@linux.intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jan H. Schönherr <jschoenh@amazon.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/2fe8e6c798e8def271122f62df9bbf58dc283e2a.1431379433.git.len.brown@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- Documentation/kernel-parameters.txt | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation/kernel-parameters.txt') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 61ab1628a057..a320a41e7412 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -746,6 +746,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. cpuidle.off=1 [CPU_IDLE] disable the cpuidle sub-system + cpu_init_udelay=N + [X86] Delay for N microsec between assert and de-assert + of APIC INIT to start processors. This delay occurs + on every CPU online, such as boot, and resume from suspend. + Default: 10000 + cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver Format: <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] -- cgit v1.2.3