From: Jack Steiner <steiner@sgi.com>
To: mingo@elte.hu, tglx@linutronix.de
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH] x86, UV: Remove UV delay in starting slave cpus
Date: Fri, 5 Aug 2011 09:09:00 -0500 [thread overview]
Message-ID: <20110805140900.GA6774@sgi.com> (raw)
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@sgi.com>
---
arch/x86/kernel/apic/x2apic_uv_x.c | 1 -
1 file changed, 1 deletion(-)
Index: linux/arch/x86/kernel/apic/x2apic_uv_x.c
===================================================================
--- linux.orig/arch/x86/kernel/apic/x2apic_uv_x.c 2011-08-05 08:22:42.511980932 -0500
+++ linux/arch/x86/kernel/apic/x2apic_uv_x.c 2011-08-05 08:23:27.488613896 -0500
@@ -207,7 +207,6 @@ static int __cpuinit uv_wakeup_secondary
((start_rip << UVH_IPI_INT_VECTOR_SHFT) >> 12) |
APIC_DM_INIT;
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) |
next reply other threads:[~2011-08-05 14:09 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-05 14:09 Jack Steiner [this message]
2011-08-09 14:29 ` [tip:x86/urgent] x86, UV: Remove UV delay in starting slave cpus tip-bot for Jack Steiner
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