[34-longterm 169/179] x86, UV: Remove UV delay in starting slave cpus

From: Paul Gortmaker
Date: Mon May 14 2012 - 22:27:48 EST

From: Jack Steiner <steiner@xxxxxxx>

This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.

commit 05e33fc20ea5e493a2a1e7f1d04f43cdf89f83ed upstream.

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>
Link: http://lkml.kernel.org/r/20110805140900.GA6774@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
arch/x86/kernel/apic/x2apic_uv_x.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index 25a1b3c..2872559 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -144,7 +144,6 @@ 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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