Skip to contentSkip to conversation

x86: Remove EXPERIMENTAL restriction from CONFIG_HOTPLUG_CPU

PATCH In review Dimitri Sivanich 3 participants 4 messages Aug 11, 2008 – Aug 13, 2008 x86

lore
Share & tools
lore

Dimitri Sivanich

author
#0 lore raw

PATCH 1/1 x86: Remove EXPERIMENTAL restriction from CONFIG_HOTPLUG_CPU

This removes the EXPERIMENTAL restriction from CONFIG_HOTPLUG_CPU on the x86 architecture.

One question, should we default to 'Y'?

Signed-off-by Dimitri Sivanich <[email protected]>
arch/x86/Kconfig +4 -4
Index: linux/arch/x86/Kconfig
===================================================================
@@ -1365,11 +1365,11 @@ config PHYSICAL_ALIGN
 	  Don't change this unless you know what you are doing.
 
 config HOTPLUG_CPU
-	bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
-	depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
+	bool "Support for suspend on SMP and hot-pluggable CPUs"
+	depends on SMP && HOTPLUG && !X86_VOYAGER
 	---help---
-	  Say Y here to experiment with turning CPUs off and on, and to
-	  enable suspend on SMP systems. CPUs can be controlled through
+	  Say Y here to allow turning CPUs off and on, and to enable
+	  suspend on SMP systems. CPUs can be controlled through
 	  /sys/devices/system/cpu.
 	  Say N if you want to disable CPU hotplug and don't need to
 	  suspend.
#1 lore raw
Quoted 4 lines · Dimitri Sivanich

This removes the EXPERIMENTAL restriction from CONFIG_HOTPLUG_CPU on the x86 architecture.

One question, should we default to 'Y'?

CONFIG_SUSPECT will select it anyway, and when suspend is disabled in all likelyhood it's an UP system that does not need any hotplug CPU support. So we dont want to enable it by default.

Review

Quoted 13 lines

config HOTPLUG_CPU

(quoted diff) +4 -4
-	bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
-	depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
+	bool "Support for suspend on SMP and hot-pluggable CPUs"
+	depends on SMP && HOTPLUG && !X86_VOYAGER
 	---help---
-	  Say Y here to experiment with turning CPUs off and on, and to
-	  enable suspend on SMP systems. CPUs can be controlled through
+	  Say Y here to allow turning CPUs off and on, and to enable
+	  suspend on SMP systems. CPUs can be controlled through
 	  /sys/devices/system/cpu.
 	  Say N if you want to disable CPU hotplug and don't need to
 	  suspend.

actually, the original text was incorrect/outdated, as HOTPLUG_CPU was already selected outside of EXPERIMENTAL, by PM_SLEEP_SMP.

So for all practical purposes HOTPLUG_CPU was already enabled in the Linux distro space by the side-effect of SUSPEND+PM_SLEEP enabling.

Where this change might matter is when CONFIG_PM is disabled intentionally on SMP - which is rather rare.

So i've clarified the text as per the commit below - is this fine with you?

Ingo

------------------>

Quoted 1 line

From 7c13e6a3d15a4ebcc3f40df5f4d19665479f8ca3 Mon Sep 17 00:00:00 2001

From: Dimitri Sivanich <[email protected]>
Date: Mon, 11 Aug 2008 10:46:46 -0500
Subject: [PATCH] x86: remove EXPERIMENTAL restriction from CONFIG_HOTPLUG_CPU

This removes the EXPERIMENTAL restriction from CONFIG_HOTPLUG_CPU on the x86 architecture.

Signed-off-by Dimitri Sivanich <[email protected]>
Signed-off-by Ingo Molnar <[email protected]>
---
 arch/x86/Kconfig |   14 +++++++-------
 1 files changed, 7 insertions(+), 7 deletions(-)
arch/x86/Kconfig +7 -7
index 3d0f2b6..7917962 100644
@@ -1371,14 +1371,14 @@ config PHYSICAL_ALIGN
 	  Don't change this unless you know what you are doing.
 
 config HOTPLUG_CPU
-	bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
-	depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
+	bool "Support for hot-pluggable CPUs"
+	depends on SMP && HOTPLUG && !X86_VOYAGER
 	---help---
-	  Say Y here to experiment with turning CPUs off and on, and to
-	  enable suspend on SMP systems. CPUs can be controlled through
-	  /sys/devices/system/cpu.
-	  Say N if you want to disable CPU hotplug and don't need to
-	  suspend.
+	  Say Y here to allow turning CPUs off and on. CPUs can be
+	  controlled through /sys/devices/system/cpu.
+	  ( Note: power management support will enable this option
+	    automatically on SMP systems. )
+	  Say N if you want to disable CPU hotplug.
 
 config COMPAT_VDSO
 	def_bool y
author
#2 lore raw
Quoted 4 lines · Ingo Molnar

So i've clarified the text as per the commit below - is this fine with you?

Yes, the text looks OK to me.

#3 lore raw
In reply to Ingo Molnar
Quoted 9 lines · Ingo Molnar
Quoted 4 lines · Dimitri Sivanich

This removes the EXPERIMENTAL restriction from CONFIG_HOTPLUG_CPU on the x86 architecture.

One question, should we default to 'Y'?

CONFIG_SUSPECT will select it anyway, and when suspend is disabled

Nice typo ;-).

Quoted 11 lines

So i've clarified the text as per the commit below - is this fine with you?

Ingo

------------------>

Quoted 1 line

From 7c13e6a3d15a4ebcc3f40df5f4d19665479f8ca3 Mon Sep 17 00:00:00 2001

From: Dimitri Sivanich <[email protected]>
Date: Mon, 11 Aug 2008 10:46:46 -0500
Subject: [PATCH] x86: remove EXPERIMENTAL restriction from CONFIG_HOTPLUG_CPU

Quoted 5 lines

This removes the EXPERIMENTAL restriction from CONFIG_HOTPLUG_CPU on the x86 architecture.

Signed-off-by Dimitri Sivanich <[email protected]>
Signed-off-by Ingo Molnar <[email protected]>

ACK.

Signature · 2 lines
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html