diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/sbitmap.c | 74 | ||||
| -rw-r--r-- | lib/vsprintf.c | 70 |
2 files changed, 106 insertions, 38 deletions
diff --git a/lib/sbitmap.c b/lib/sbitmap.c index d3412984170c..4d188d05db15 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -208,8 +208,28 @@ static int sbitmap_find_bit_in_word(struct sbitmap_word *map, return nr; } +static unsigned int __map_depth_with_shallow(const struct sbitmap *sb, + int index, + unsigned int shallow_depth) +{ + u64 shallow_word_depth; + unsigned int word_depth, reminder; + + word_depth = __map_depth(sb, index); + if (shallow_depth >= sb->depth) + return word_depth; + + shallow_word_depth = word_depth * shallow_depth; + reminder = do_div(shallow_word_depth, sb->depth); + + if (reminder >= (index + 1) * word_depth) + shallow_word_depth++; + + return (unsigned int)shallow_word_depth; +} + static int sbitmap_find_bit(struct sbitmap *sb, - unsigned int depth, + unsigned int shallow_depth, unsigned int index, unsigned int alloc_hint, bool wrap) @@ -218,12 +238,12 @@ static int sbitmap_find_bit(struct sbitmap *sb, int nr = -1; for (i = 0; i < sb->map_nr; i++) { - nr = sbitmap_find_bit_in_word(&sb->map[index], - min_t(unsigned int, - __map_depth(sb, index), - depth), - alloc_hint, wrap); + unsigned int depth = __map_depth_with_shallow(sb, index, + shallow_depth); + if (depth) + nr = sbitmap_find_bit_in_word(&sb->map[index], depth, + alloc_hint, wrap); if (nr != -1) { nr += index << sb->shift; break; @@ -287,7 +307,22 @@ static int __sbitmap_get_shallow(struct sbitmap *sb, return sbitmap_find_bit(sb, shallow_depth, index, alloc_hint, true); } -int sbitmap_get_shallow(struct sbitmap *sb, unsigned long shallow_depth) +/** + * sbitmap_get_shallow() - Try to allocate a free bit from a &struct sbitmap, + * limiting the depth used from each word. + * @sb: Bitmap to allocate from. + * @shallow_depth: The maximum number of bits to allocate from the bitmap. + * + * This rather specific operation allows for having multiple users with + * different allocation limits. E.g., there can be a high-priority class that + * uses sbitmap_get() and a low-priority class that uses sbitmap_get_shallow() + * with a @shallow_depth of (sb->depth >> 1). Then, the low-priority + * class can only allocate half of the total bits in the bitmap, preventing it + * from starving out the high-priority class. + * + * Return: Non-negative allocated bit number if successful, -1 otherwise. + */ +static int sbitmap_get_shallow(struct sbitmap *sb, unsigned long shallow_depth) { int nr; unsigned int hint, depth; @@ -302,7 +337,6 @@ int sbitmap_get_shallow(struct sbitmap *sb, unsigned long shallow_depth) return nr; } -EXPORT_SYMBOL_GPL(sbitmap_get_shallow); bool sbitmap_any_bit_set(const struct sbitmap *sb) { @@ -406,27 +440,9 @@ EXPORT_SYMBOL_GPL(sbitmap_bitmap_show); static unsigned int sbq_calc_wake_batch(struct sbitmap_queue *sbq, unsigned int depth) { - unsigned int wake_batch; - unsigned int shallow_depth; - - /* - * Each full word of the bitmap has bits_per_word bits, and there might - * be a partial word. There are depth / bits_per_word full words and - * depth % bits_per_word bits left over. In bitwise arithmetic: - * - * bits_per_word = 1 << shift - * depth / bits_per_word = depth >> shift - * depth % bits_per_word = depth & ((1 << shift) - 1) - * - * Each word can be limited to sbq->min_shallow_depth bits. - */ - shallow_depth = min(1U << sbq->sb.shift, sbq->min_shallow_depth); - depth = ((depth >> sbq->sb.shift) * shallow_depth + - min(depth & ((1U << sbq->sb.shift) - 1), shallow_depth)); - wake_batch = clamp_t(unsigned int, depth / SBQ_WAIT_QUEUES, 1, - SBQ_WAKE_BATCH); - - return wake_batch; + return clamp_t(unsigned int, + min(depth, sbq->min_shallow_depth) / SBQ_WAIT_QUEUES, + 1, SBQ_WAKE_BATCH); } int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 3d85800757aa..eb0cb11d0d12 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -60,6 +60,20 @@ bool no_hash_pointers __ro_after_init; EXPORT_SYMBOL_GPL(no_hash_pointers); +/* + * Hashed pointers policy selected by "hash_pointers=..." boot param + * + * `auto` - Hashed pointers enabled unless disabled by slub_debug_enabled=true + * `always` - Hashed pointers enabled unconditionally + * `never` - Hashed pointers disabled unconditionally + */ +enum hash_pointers_policy { + HASH_PTR_AUTO = 0, + HASH_PTR_ALWAYS, + HASH_PTR_NEVER +}; +static enum hash_pointers_policy hash_pointers_mode __initdata; + noinline static unsigned long long simple_strntoull(const char *startp, char **endp, unsigned int base, size_t max_chars) { @@ -1699,10 +1713,9 @@ char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec, return buf; } -#pragma GCC diagnostic push -#ifndef __clang__ -#pragma GCC diagnostic ignored "-Wsuggest-attribute=format" -#endif +__diag_push(); +__diag_ignore(GCC, all, "-Wsuggest-attribute=format", + "Not a valid __printf() conversion candidate."); static char *va_format(char *buf, char *end, struct va_format *va_fmt, struct printf_spec spec) { @@ -1717,7 +1730,7 @@ static char *va_format(char *buf, char *end, struct va_format *va_fmt, return buf; } -#pragma GCC diagnostic pop +__diag_pop(); static noinline_for_stack char *uuid_string(char *buf, char *end, const u8 *addr, @@ -2289,12 +2302,23 @@ char *resource_or_range(const char *fmt, char *buf, char *end, void *ptr, return resource_string(buf, end, ptr, spec, fmt); } -int __init no_hash_pointers_enable(char *str) +void __init hash_pointers_finalize(bool slub_debug) { - if (no_hash_pointers) - return 0; + switch (hash_pointers_mode) { + case HASH_PTR_ALWAYS: + no_hash_pointers = false; + break; + case HASH_PTR_NEVER: + no_hash_pointers = true; + break; + case HASH_PTR_AUTO: + default: + no_hash_pointers = slub_debug; + break; + } - no_hash_pointers = true; + if (!no_hash_pointers) + return; pr_warn("**********************************************************\n"); pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); @@ -2307,11 +2331,39 @@ int __init no_hash_pointers_enable(char *str) pr_warn("** the kernel, report this immediately to your system **\n"); pr_warn("** administrator! **\n"); pr_warn("** **\n"); + pr_warn("** Use hash_pointers=always to force this mode off **\n"); + pr_warn("** **\n"); pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); pr_warn("**********************************************************\n"); +} + +static int __init hash_pointers_mode_parse(char *str) +{ + if (!str) { + pr_warn("Hash pointers mode empty; falling back to auto.\n"); + hash_pointers_mode = HASH_PTR_AUTO; + } else if (strncmp(str, "auto", 4) == 0) { + pr_info("Hash pointers mode set to auto.\n"); + hash_pointers_mode = HASH_PTR_AUTO; + } else if (strncmp(str, "never", 5) == 0) { + pr_info("Hash pointers mode set to never.\n"); + hash_pointers_mode = HASH_PTR_NEVER; + } else if (strncmp(str, "always", 6) == 0) { + pr_info("Hash pointers mode set to always.\n"); + hash_pointers_mode = HASH_PTR_ALWAYS; + } else { + pr_warn("Unknown hash_pointers mode '%s' specified; assuming auto.\n", str); + hash_pointers_mode = HASH_PTR_AUTO; + } return 0; } +early_param("hash_pointers", hash_pointers_mode_parse); + +static int __init no_hash_pointers_enable(char *str) +{ + return hash_pointers_mode_parse("never"); +} early_param("no_hash_pointers", no_hash_pointers_enable); /* |