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From: Andi Kleen <andi@firstfloor.org>
To: ying.huang@intel.com, x86@kernel.org, akpm@linux-foundation.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] [1/3] x86: Improve CONFIG_KEXEC_JUMP description
Date: Sun,  6 Dec 2009 15:13:09 +0100 (CET)	[thread overview]
Message-ID: <20091206313.812075626@firstfloor.org> (raw)


I've been puzzling what CONFIG_KEXEC_JUMP was good for.

The Kconfig help was not very helpful in explaining why one
want to set this option. This patch improves 
it a bit, based on the original commit log. It's still
not fully clear, but then I couldn't find a concrete application
anywhere.

Cc: ying.huang@intel.com
Signed-off-by: Andi Kleen <ak@linux.intel.com>

---
 arch/x86/Kconfig |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Index: linux-2.6.32-ak/arch/x86/Kconfig
===================================================================
--- linux-2.6.32-ak.orig/arch/x86/Kconfig
+++ linux-2.6.32-ak/arch/x86/Kconfig
@@ -1496,8 +1496,10 @@ config KEXEC_JUMP
 	depends on EXPERIMENTAL
 	depends on KEXEC && HIBERNATION
 	---help---
-	  Jump between original kernel and kexeced kernel and invoke
-	  code in physical address mode via KEXEC
+	  Allow to call code through kexec with paging turned off and then
+	  return to the normal kernel. This can be used to call BIOS
+	  code for example, and to implement kexec based hibernation.
+	  Requires uptodate kexec tools.
 
 config PHYSICAL_START
 	hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)

             reply	other threads:[~2009-12-06 14:13 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-12-06 14:13 Andi Kleen [this message]
2009-12-06 14:13 ` [PATCH] [2/3] x86: Remove CONFIG_GBPAGES option Andi Kleen
2009-12-06 14:13 ` [PATCH] [3/3] Fix unwind annotations for 64bit kernel Andi Kleen
2009-12-07  7:53   ` Jan Beulich
2009-12-07  9:06     ` Andi Kleen

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