diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 7 | ||||
| -rw-r--r-- | lib/cmdline.c | 35 |
2 files changed, 40 insertions, 2 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 diff --git a/lib/cmdline.c b/lib/cmdline.c index 0331ed825ea7..8a5b5303bd4f 100644 --- a/lib/cmdline.c +++ b/lib/cmdline.c @@ -16,6 +16,23 @@ #include <linux/kernel.h> #include <linux/string.h> +/* + * If a hyphen was found in get_option, this will handle the + * range of numbers, M-N. This will expand the range and insert + * the values[M, M+1, ..., N] into the ints array in get_options. + */ + +static int get_range(char **str, int *pint) +{ + int x, inc_counter, upper_range; + + (*str)++; + upper_range = simple_strtol((*str), NULL, 0); + inc_counter = upper_range - *pint; + for (x = *pint; x < upper_range; x++) + *pint++ = x; + return inc_counter; +} /** * get_option - Parse integer from an option string @@ -29,6 +46,7 @@ * 0 : no int in string * 1 : int found, no subsequent comma * 2 : int found including a subsequent comma + * 3 : hyphen found to denote a range */ int get_option (char **str, int *pint) @@ -44,6 +62,8 @@ int get_option (char **str, int *pint) (*str)++; return 2; } + if (**str == '-') + return 3; return 1; } @@ -55,7 +75,8 @@ int get_option (char **str, int *pint) * @ints: integer array * * This function parses a string containing a comma-separated - * list of integers. The parse halts when the array is + * list of integers, a hyphen-separated range of _positive_ integers, + * or a combination of both. The parse halts when the array is * full, or when no more numbers can be retrieved from the * string. * @@ -72,6 +93,18 @@ char *get_options(const char *str, int nints, int *ints) res = get_option ((char **)&str, ints + i); if (res == 0) break; + if (res == 3) { + int range_nums; + range_nums = get_range((char **)&str, ints + i); + if (range_nums < 0) + break; + /* + * Decrement the result by one to leave out the + * last number in the range. The next iteration + * will handle the upper number in the range + */ + i += (range_nums - 1); + } i++; if (res == 1) break; |