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

[Ahmed S. Darwish]

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
 			Format:
 			<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
 
-	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.
 
 	crashkernel=range1:size1[,range2:size2,...][@offset]
 			[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>
> 

thanks,

-- 
Darwish
http://darwish.07.googlepages.com