diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.rst | 5 | ||||
| -rw-r--r-- | lib/bitmap.c | 9 | ||||
| -rw-r--r-- | lib/test_bitmap.c | 7 |
3 files changed, 21 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.rst b/Documentation/admin-guide/kernel-parameters.rst index 3996b54158bf..01ba293a2d70 100644 --- a/Documentation/admin-guide/kernel-parameters.rst +++ b/Documentation/admin-guide/kernel-parameters.rst @@ -76,6 +76,11 @@ to change, such as less cores in the CPU list, then N and any ranges using N will also change. Use the same on a small 4 core system, and "16-N" becomes "16-3" and now the same boot input will be flagged as invalid (start > end). +The special case-tolerant group name "all" has a meaning of selecting all CPUs, +so that "nohz_full=all" is the equivalent of "nohz_full=0-N". + +The semantics of "N" and "all" is supported on a level of bitmaps and holds for +all users of bitmap_parse(). This document may not be entirely up to date and comprehensive. The command "modinfo -p ${modulename}" shows a current list of all parameters of a loadable diff --git a/lib/bitmap.c b/lib/bitmap.c index 74ceb02f45e3..6e29b2aae6ba 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -581,6 +581,14 @@ static const char *bitmap_parse_region(const char *str, struct region *r) { unsigned int lastbit = r->nbits - 1; + if (!strncasecmp(str, "all", 3)) { + r->start = 0; + r->end = lastbit; + str += 3; + + goto check_pattern; + } + str = bitmap_getnum(str, &r->start, lastbit); if (IS_ERR(str)) return str; @@ -595,6 +603,7 @@ static const char *bitmap_parse_region(const char *str, struct region *r) if (IS_ERR(str)) return str; +check_pattern: if (end_of_region(*str)) goto no_pattern; diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c index 9cd575583180..4ea73f5aed41 100644 --- a/lib/test_bitmap.c +++ b/lib/test_bitmap.c @@ -366,6 +366,13 @@ static const struct test_bitmap_parselist parselist_tests[] __initconst = { {0, "0-31:1/3,1-31:1/3,2-31:1/3", &exp1[8 * step], 32, 0}, {0, "1-10:8/12,8-31:24/29,0-31:0/3", &exp1[9 * step], 32, 0}, + {0, "all", &exp1[8 * step], 32, 0}, + {0, "0, 1, all, ", &exp1[8 * step], 32, 0}, + {0, "all:1/2", &exp1[4 * step], 32, 0}, + {0, "ALL:1/2", &exp1[4 * step], 32, 0}, + {-EINVAL, "al", NULL, 8, 0}, + {-EINVAL, "alll", NULL, 8, 0}, + {-EINVAL, "-1", NULL, 8, 0}, {-EINVAL, "-0", NULL, 8, 0}, {-EINVAL, "10-1", NULL, 8, 0}, |