From 494215fbf298787e4ead16e4c68634d241336b02 Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Sun, 21 Feb 2021 03:08:20 -0500 Subject: lib: test_bitmap: clearly separate ERANGE from EINVAL tests. This block of tests was meant to find/flag incorrect use of the ":" and "/" separators (syntax errors) and invalid (zero) group len. However they were specified with an 8 bit width and 32 bit operations, so they really contained two errors (EINVAL and ERANGE). Promote them to 32 bit so it is clear what they are meant to target. Then we can add tests specific for ERANGE (no syntax errors, just doing 32bit op on 8 bit width, plus a typical 9-on-8 fencepost error). Cc: Yury Norov Cc: Rasmus Villemoes Cc: Andy Shevchenko Acked-by: Yury Norov Reviewed-by: Andy Shevchenko Signed-off-by: Paul Gortmaker Signed-off-by: Paul E. McKenney --- lib/test_bitmap.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'lib') diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c index 0ea0e8258f14..853a3a6ff59c 100644 --- a/lib/test_bitmap.c +++ b/lib/test_bitmap.c @@ -337,12 +337,12 @@ static const struct test_bitmap_parselist parselist_tests[] __initconst = { {-EINVAL, "-1", NULL, 8, 0}, {-EINVAL, "-0", NULL, 8, 0}, {-EINVAL, "10-1", NULL, 8, 0}, - {-EINVAL, "0-31:", NULL, 8, 0}, - {-EINVAL, "0-31:0", NULL, 8, 0}, - {-EINVAL, "0-31:0/", NULL, 8, 0}, - {-EINVAL, "0-31:0/0", NULL, 8, 0}, - {-EINVAL, "0-31:1/0", NULL, 8, 0}, - {-EINVAL, "0-31:10/1", NULL, 8, 0}, + {-EINVAL, "0-31:", NULL, 32, 0}, + {-EINVAL, "0-31:0", NULL, 32, 0}, + {-EINVAL, "0-31:0/", NULL, 32, 0}, + {-EINVAL, "0-31:0/0", NULL, 32, 0}, + {-EINVAL, "0-31:1/0", NULL, 32, 0}, + {-EINVAL, "0-31:10/1", NULL, 32, 0}, {-EOVERFLOW, "0-98765432123456789:10/1", NULL, 8, 0}, {-EINVAL, "a-31", NULL, 8, 0}, -- cgit v1.2.3 From 6fef5905fbd691aeb91093056b27d5ee7b106097 Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Sun, 21 Feb 2021 03:08:21 -0500 Subject: lib: test_bitmap: add tests to trigger ERANGE case. Add tests that specify a valid range, but one that is outside the width of the bitmap for which it is to be applied to. These should trigger an -ERANGE response from the code. Cc: Yury Norov Cc: Rasmus Villemoes Cc: Andy Shevchenko Acked-by: Yury Norov Reviewed-by: Andy Shevchenko Signed-off-by: Paul Gortmaker Signed-off-by: Paul E. McKenney --- lib/test_bitmap.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'lib') diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c index 853a3a6ff59c..0f2e91d0a84c 100644 --- a/lib/test_bitmap.c +++ b/lib/test_bitmap.c @@ -337,6 +337,8 @@ static const struct test_bitmap_parselist parselist_tests[] __initconst = { {-EINVAL, "-1", NULL, 8, 0}, {-EINVAL, "-0", NULL, 8, 0}, {-EINVAL, "10-1", NULL, 8, 0}, + {-ERANGE, "8-8", NULL, 8, 0}, + {-ERANGE, "0-31", NULL, 8, 0}, {-EINVAL, "0-31:", NULL, 32, 0}, {-EINVAL, "0-31:0", NULL, 32, 0}, {-EINVAL, "0-31:0/", NULL, 32, 0}, -- cgit v1.2.3 From 97330db3af9a41302d1ccb0f495fcb5b5da2cc44 Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Sun, 21 Feb 2021 03:08:22 -0500 Subject: lib: test_bitmap: add more start-end:offset/len tests There are inputs to bitmap_parselist() that would probably never be entered manually by a person, but might result from some kind of automated input generator. Things like ranges of length 1, or group lengths longer than nbits, overlaps, or offsets of zero. Adding these tests serve two purposes: 1) document what might seem odd but nonetheless valid input. 2) don't regress from what we currently accept as valid. Cc: Yury Norov Cc: Rasmus Villemoes Cc: Andy Shevchenko Acked-by: Yury Norov Reviewed-by: Andy Shevchenko Signed-off-by: Paul Gortmaker Signed-off-by: Paul E. McKenney --- lib/test_bitmap.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'lib') diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c index 0f2e91d0a84c..3c1c46deb8fe 100644 --- a/lib/test_bitmap.c +++ b/lib/test_bitmap.c @@ -34,6 +34,8 @@ static const unsigned long exp1[] __initconst = { BITMAP_FROM_U64(0x3333333311111111ULL), BITMAP_FROM_U64(0xffffffff77777777ULL), BITMAP_FROM_U64(0), + BITMAP_FROM_U64(0x00008000), + BITMAP_FROM_U64(0x80000000), }; static const unsigned long exp2[] __initconst = { @@ -334,6 +336,26 @@ static const struct test_bitmap_parselist parselist_tests[] __initconst = { {0, " , ,, , , ", &exp1[12 * step], 8, 0}, {0, " , ,, , , \n", &exp1[12 * step], 8, 0}, + {0, "0-0", &exp1[0], 32, 0}, + {0, "1-1", &exp1[1 * step], 32, 0}, + {0, "15-15", &exp1[13 * step], 32, 0}, + {0, "31-31", &exp1[14 * step], 32, 0}, + + {0, "0-0:0/1", &exp1[12 * step], 32, 0}, + {0, "0-0:1/1", &exp1[0], 32, 0}, + {0, "0-0:1/31", &exp1[0], 32, 0}, + {0, "0-0:31/31", &exp1[0], 32, 0}, + {0, "1-1:1/1", &exp1[1 * step], 32, 0}, + {0, "0-15:16/31", &exp1[2 * step], 32, 0}, + {0, "15-15:1/2", &exp1[13 * step], 32, 0}, + {0, "15-15:31/31", &exp1[13 * step], 32, 0}, + {0, "15-31:1/31", &exp1[13 * step], 32, 0}, + {0, "16-31:16/31", &exp1[3 * step], 32, 0}, + {0, "31-31:31/31", &exp1[14 * step], 32, 0}, + + {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}, + {-EINVAL, "-1", NULL, 8, 0}, {-EINVAL, "-0", NULL, 8, 0}, {-EINVAL, "10-1", NULL, 8, 0}, -- cgit v1.2.3 From 9d7a3366b7028ae8dd16a0d7585cbf11b03b42a0 Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Sun, 21 Feb 2021 03:08:23 -0500 Subject: lib: bitmap: fold nbits into region struct This will reduce parameter passing and enable using nbits as part of future dynamic region parameter parsing. Cc: Yury Norov Cc: Rasmus Villemoes Cc: Andy Shevchenko Suggested-by: Yury Norov Acked-by: Yury Norov Reviewed-by: Andy Shevchenko Signed-off-by: Paul Gortmaker Signed-off-by: Paul E. McKenney --- lib/bitmap.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) (limited to 'lib') diff --git a/lib/bitmap.c b/lib/bitmap.c index 75006c4036e9..162e2850c622 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -487,24 +487,24 @@ EXPORT_SYMBOL(bitmap_print_to_pagebuf); /* * Region 9-38:4/10 describes the following bitmap structure: - * 0 9 12 18 38 - * .........****......****......****...... - * ^ ^ ^ ^ - * start off group_len end + * 0 9 12 18 38 N + * .........****......****......****.................. + * ^ ^ ^ ^ ^ + * start off group_len end nbits */ struct region { unsigned int start; unsigned int off; unsigned int group_len; unsigned int end; + unsigned int nbits; }; -static int bitmap_set_region(const struct region *r, - unsigned long *bitmap, int nbits) +static int bitmap_set_region(const struct region *r, unsigned long *bitmap) { unsigned int start; - if (r->end >= nbits) + if (r->end >= r->nbits) return -ERANGE; for (start = r->start; start <= r->end; start += r->group_len) @@ -640,7 +640,8 @@ int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) struct region r; long ret; - bitmap_zero(maskp, nmaskbits); + r.nbits = nmaskbits; + bitmap_zero(maskp, r.nbits); while (buf) { buf = bitmap_find_region(buf); @@ -655,7 +656,7 @@ int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) if (ret) return ret; - ret = bitmap_set_region(&r, maskp, nmaskbits); + ret = bitmap_set_region(&r, maskp); if (ret) return ret; } -- cgit v1.2.3 From f3c869caef648c541a7445f2a6ba2196d343f542 Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Sun, 21 Feb 2021 03:08:24 -0500 Subject: lib: bitmap: move ERANGE check from set_region to check_region It makes sense to do all the checks in check_region() and not 1/2 in check_region and 1/2 in set_region. Since set_region is called immediately after check_region, the net effect on runtime is zero, but it gets rid of an if (...) return... Cc: Yury Norov Cc: Rasmus Villemoes Cc: Andy Shevchenko Acked-by: Yury Norov Reviewed-by: Andy Shevchenko Signed-off-by: Paul Gortmaker Signed-off-by: Paul E. McKenney --- lib/bitmap.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) (limited to 'lib') diff --git a/lib/bitmap.c b/lib/bitmap.c index 162e2850c622..833f152a2c43 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -500,17 +500,12 @@ struct region { unsigned int nbits; }; -static int bitmap_set_region(const struct region *r, unsigned long *bitmap) +static void bitmap_set_region(const struct region *r, unsigned long *bitmap) { unsigned int start; - if (r->end >= r->nbits) - return -ERANGE; - for (start = r->start; start <= r->end; start += r->group_len) bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); - - return 0; } static int bitmap_check_region(const struct region *r) @@ -518,6 +513,9 @@ static int bitmap_check_region(const struct region *r) if (r->start > r->end || r->group_len == 0 || r->off > r->group_len) return -EINVAL; + if (r->end >= r->nbits) + return -ERANGE; + return 0; } @@ -656,9 +654,7 @@ int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) if (ret) return ret; - ret = bitmap_set_region(&r, maskp); - if (ret) - return ret; + bitmap_set_region(&r, maskp); } return 0; -- cgit v1.2.3 From 2c4885d24e64941702a8f81c8e83289823ba35d0 Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Sun, 21 Feb 2021 03:08:25 -0500 Subject: lib: bitmap: support "N" as an alias for size of bitmap While this is done for all bitmaps, the original use case in mind was for CPU masks and cpulist_parse() as described below. It seems that a common configuration is to use the 1st couple cores for housekeeping tasks. This tends to leave the remaining ones to form a pool of similarly configured cores to take on the real workload of interest to the user. So on machine A - with 32 cores, it could be 0-3 for "system" and then 4-31 being used in boot args like nohz_full=, or rcu_nocbs= as part of setting up the worker pool of CPUs. But then newer machine B is added, and it has 48 cores, and so while the 0-3 part remains unchanged, the pool setup cpu list becomes 4-47. Multiple deployment becomes easier when we can just simply replace 31 and 47 with "N" and let the system substitute in the actual number at boot; a number that it knows better than we do. Cc: Yury Norov Cc: Peter Zijlstra Cc: "Paul E. McKenney" Cc: Rasmus Villemoes Cc: Andy Shevchenko Suggested-by: Yury Norov # move it from CPU code Acked-by: Yury Norov Signed-off-by: Paul Gortmaker Signed-off-by: Paul E. McKenney --- Documentation/admin-guide/kernel-parameters.rst | 7 +++++++ lib/bitmap.c | 22 +++++++++++++++++----- 2 files changed, 24 insertions(+), 5 deletions(-) (limited to 'lib') diff --git a/Documentation/admin-guide/kernel-parameters.rst b/Documentation/admin-guide/kernel-parameters.rst index 1132796a8d96..d6e3f67953a7 100644 --- a/Documentation/admin-guide/kernel-parameters.rst +++ b/Documentation/admin-guide/kernel-parameters.rst @@ -68,6 +68,13 @@ For example one can add to the command line following parameter: where the final item represents CPUs 100,101,125,126,150,151,... +The value "N" can be used to represent the numerically last CPU on the system, +i.e "foo_cpus=16-N" would be equivalent to "16-31" on a 32 core system. + +Keep in mind that "N" is dynamic, so if system changes cause the bitmap width +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). This document may not be entirely up to date and comprehensive. The command diff --git a/lib/bitmap.c b/lib/bitmap.c index 833f152a2c43..9f4626a4c95f 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -519,11 +519,17 @@ static int bitmap_check_region(const struct region *r) return 0; } -static const char *bitmap_getnum(const char *str, unsigned int *num) +static const char *bitmap_getnum(const char *str, unsigned int *num, + unsigned int lastbit) { unsigned long long n; unsigned int len; + if (str[0] == 'N') { + *num = lastbit; + return str + 1; + } + len = _parse_integer(str, 10, &n); if (!len) return ERR_PTR(-EINVAL); @@ -571,7 +577,9 @@ static const char *bitmap_find_region_reverse(const char *start, const char *end static const char *bitmap_parse_region(const char *str, struct region *r) { - str = bitmap_getnum(str, &r->start); + unsigned int lastbit = r->nbits - 1; + + str = bitmap_getnum(str, &r->start, lastbit); if (IS_ERR(str)) return str; @@ -581,7 +589,7 @@ static const char *bitmap_parse_region(const char *str, struct region *r) if (*str != '-') return ERR_PTR(-EINVAL); - str = bitmap_getnum(str + 1, &r->end); + str = bitmap_getnum(str + 1, &r->end, lastbit); if (IS_ERR(str)) return str; @@ -591,14 +599,14 @@ static const char *bitmap_parse_region(const char *str, struct region *r) if (*str != ':') return ERR_PTR(-EINVAL); - str = bitmap_getnum(str + 1, &r->off); + str = bitmap_getnum(str + 1, &r->off, lastbit); if (IS_ERR(str)) return str; if (*str != '/') return ERR_PTR(-EINVAL); - return bitmap_getnum(str + 1, &r->group_len); + return bitmap_getnum(str + 1, &r->group_len, lastbit); no_end: r->end = r->start; @@ -625,6 +633,10 @@ no_pattern: * From each group will be used only defined amount of bits. * Syntax: range:used_size/group_size * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 + * The value 'N' can be used as a dynamically substituted token for the + * maximum allowed value; i.e (nmaskbits - 1). Keep in mind that it is + * dynamic, so if system changes cause the bitmap width to change, such + * as more cores in a CPU list, then any ranges using N will also change. * * Returns: 0 on success, -errno on invalid input strings. Error values: * -- cgit v1.2.3 From 99c58d1adbca25fb3ee2469bf0904e1e3e021f7e Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Sun, 21 Feb 2021 03:08:26 -0500 Subject: lib: test_bitmap: add tests for "N" alias These are copies of existing tests, with just 31 --> N. This ensures the recently added "N" alias transparently works in any normally numeric fields of a region specification. Cc: Yury Norov Cc: Rasmus Villemoes Cc: Andy Shevchenko Acked-by: Yury Norov Signed-off-by: Paul Gortmaker Signed-off-by: Paul E. McKenney --- lib/test_bitmap.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'lib') diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c index 3c1c46deb8fe..9cd575583180 100644 --- a/lib/test_bitmap.c +++ b/lib/test_bitmap.c @@ -353,6 +353,16 @@ static const struct test_bitmap_parselist parselist_tests[] __initconst = { {0, "16-31:16/31", &exp1[3 * step], 32, 0}, {0, "31-31:31/31", &exp1[14 * step], 32, 0}, + {0, "N-N", &exp1[14 * step], 32, 0}, + {0, "0-0:1/N", &exp1[0], 32, 0}, + {0, "0-0:N/N", &exp1[0], 32, 0}, + {0, "0-15:16/N", &exp1[2 * step], 32, 0}, + {0, "15-15:N/N", &exp1[13 * step], 32, 0}, + {0, "15-N:1/N", &exp1[13 * step], 32, 0}, + {0, "16-N:16/N", &exp1[3 * step], 32, 0}, + {0, "N-N:N/N", &exp1[14 * step], 32, 0}, + + {0, "0-N:1/3,1-N:1/3,2-N:1/3", &exp1[8 * step], 32, 0}, {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}, -- cgit v1.2.3