[tip:x86/urgent] x86, UV: Remove UV delay in starting slave cpus

From: tip-bot for Jack Steiner
Date: Tue Aug 09 2011 - 10:29:21 EST

Commit-ID: 05e33fc20ea5e493a2a1e7f1d04f43cdf89f83ed
Gitweb: http://git.kernel.org/tip/05e33fc20ea5e493a2a1e7f1d04f43cdf89f83ed
Author: Jack Steiner <steiner@xxxxxxx>
AuthorDate: Fri, 5 Aug 2011 09:09:00 -0500
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Fri, 5 Aug 2011 23:48:34 +0200

x86, UV: Remove UV delay in starting slave cpus

Delete the 10 msec delay between the INIT and SIPI when starting
slave cpus. I can find no requirement for this delay. BIOS also
has similar code sequences without the delay.

Removing the delay reduces boot time by 40 sec. Every bit helps.

Signed-off-by: Jack Steiner <steiner@xxxxxxx>
Cc: <stable@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20110805140900.GA6774@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
arch/x86/kernel/apic/x2apic_uv_x.c | 1 -
1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index adc66c3..34b1859 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -207,7 +207,6 @@ static int __cpuinit uv_wakeup_secondary(int phys_apicid, unsigned long start_ri
((start_rip << UVH_IPI_INT_VECTOR_SHFT) >> 12) |
uv_write_global_mmr64(pnode, UVH_IPI_INT, val);
- mdelay(10);

val = (1UL << UVH_IPI_INT_SEND_SHFT) |
(phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) |
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