[PATCH v3 -next] Documentation: Improve crashkernel= description

Ahmed S. Darwish darwish.07 at gmail.com
Mon Feb 7 11:01:27 EST 2011

On Mon, Feb 07, 2011 at 09:25:50AM -0500, Vivek Goyal wrote:
> On Mon, Feb 07, 2011 at 01:30:54PM +0200, Ahmed S. Darwish wrote:
> > 
> > Had to explore two C code files to make sense of the 'crashkernel='
> > kernel parameter values.  Improve the situation.
> > 
> Did you look at Documentation/kdump/kdump.txt before looking into the
> code. I thought kdump.txt explained the meaning of crashkernel= well.
> In case if it was not obivious that for further details look into
> kdump.txt, I will suggest to add a line asking reader to look into
> kdump.txt for more details.

Yes, I jumped to the code first :-) Here's a new patch with the link:

(Also applicable over latest -rc3)


Complete the crashkernel= kernel parameter documentation.

Signed-off-by: Ahmed S. Darwish <darwish.07 at gmail.com>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 89835a4..050b0e5 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -545,16 +545,20 @@ and is between 256 and 4096 characters. It is defined in the file
-	crashkernel=nn[KMG]@ss[KMG]
-			[KNL] Reserve a chunk of physical memory to
-			hold a kernel to switch to with kexec on panic.
+	crashkernel=size[KMG][@offset[KMG]]
+			[KNL] Using kexec, Linux can switch to a 'crash kernel'
+			upon panic. This parameter reserves the physical
+			memory region [offset, offset + size] for that kernel
+			image. If '@offset' is omitted, then a suitable offset
+			is selected automatically. Check
+			Documentation/kdump/kdump.txt for further details.
 			[KNL] Same as above, but depends on the memory
 			in the running system. The syntax of range is
 			start-[end] where start and end are both
 			a memory unit (amount[KMG]). See also
-			Documentation/kdump/kdump.txt for a example.
+			Documentation/kdump/kdump.txt for an example.
 	cs89x0_dma=	[HW,NET]
 			Format: <dma>

> Acked-by: Vivek Goyal <vgoyal at redhat.com>



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