[PATCH] get_options to allow a hypenated range for isolcpus

This allows a hyphenated range of positive numbers in the string passed
to command line helper function, get_options.

Currently the command line option "isolcpus=" takes as its argument a
list of cpus.

Format: <cpu number>,...,<cpu number>
Valid values of <cpu_number>  include all cpus, 0 to "number of CPUs in
system - 1". This can get extremely long when isolating the majority of
cpus on a large system.  The kernel isolcpus code would not need any
changing to use this feature.  To use it, the change would be in the
command line format for 'isolcpus='
Format:
<cpu number>,...,<cpu number>
or
<cpu number>-<cpu number>  (must be a positive range in ascending
order.)
or a mixture
<cpu number>,...,<cpu number>-<cpu number>

Signed-off-by: Derek Fults <dfults@sgi.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 1e183bd33d71..8fe6b834ef27 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -714,7 +714,12 @@ and is between 256 and 4096 characters. It is defined in the file
                         Format: <RDP>,<reset>,<pci_scan>,<verbosity>
 
         isolcpus=       [KNL,SMP] Isolate CPUs from the general scheduler.
-                        Format: <cpu number>,...,<cpu number>
+                        Format:
+                        <cpu number>,...,<cpu number>
+                        or
+                        <cpu number>-<cpu number>  (must be a positive range in ascending order)
+                        or a mixture
+                        <cpu number>,...,<cpu number>-<cpu number>
                         This option can be used to specify one or more CPUs
                         to isolate from the general SMP balancing and scheduling
                         algorithms. The only way to move a process onto or off