---

yaml
---
r: 71515
b: refs/heads/master
c: fb39159
h: refs/heads/master
i:
  71513: 3337f18
  71511: 3ab0245
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 7d7712a385d5b0a6f921dbd9b66ad3aaed387b5e
+refs/heads/master: fb391599f2eaf22197e3e914187c957ef7eeb4c5

trunk/Documentation/kdump/kdump.txt

@@ -231,6 +231,32 @@ Dump-capture kernel config options (Arch Dependent, ia64)
   any space below the alignment point will be wasted.
 
 
+Extended crashkernel syntax
+===========================
+
+While the "crashkernel=size[@offset]" syntax is sufficient for most
+configurations, sometimes it's handy to have the reserved memory dependent
+on the value of System RAM -- that's mostly for distributors that pre-setup
+the kernel command line to avoid a unbootable system after some memory has
+been removed from the machine.
+
+The syntax is:
+
+    crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
+    range=start-[end]
+
+For example:
+
+    crashkernel=512M-2G:64M,2G-:128M
+
+This would mean:
+
+    1) if the RAM is smaller than 512M, then don't reserve anything
+       (this is the "rescue" case)
+    2) if the RAM size is between 512M and 2G, then reserve 64M
+    3) if the RAM size is larger than 2G, then reserve 128M
+
+
 Boot into System Kernel
 =======================
 

trunk/Documentation/kernel-parameters.txt

@@ -497,6 +497,13 @@ and is between 256 and 4096 characters. It is defined in the file
 			[KNL] Reserve a chunk of physical memory to
 			hold a kernel to switch to with kexec on panic.
 
+	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.
+
 	cs4232=		[HW,OSS]
 			Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>