diff options
Diffstat (limited to 'tools/sched_ext/include/scx/common.bpf.h')
| -rw-r--r-- | tools/sched_ext/include/scx/common.bpf.h | 85 |
1 files changed, 57 insertions, 28 deletions
diff --git a/tools/sched_ext/include/scx/common.bpf.h b/tools/sched_ext/include/scx/common.bpf.h index dc4333d23189..8787048c6762 100644 --- a/tools/sched_ext/include/scx/common.bpf.h +++ b/tools/sched_ext/include/scx/common.bpf.h @@ -586,36 +586,48 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s } } -#define READ_ONCE(x) \ -({ \ - union { typeof(x) __val; char __c[1]; } __u = \ - { .__c = { 0 } }; \ - __read_once_size(&(x), __u.__c, sizeof(x)); \ - __u.__val; \ -}) - -#define WRITE_ONCE(x, val) \ -({ \ - union { typeof(x) __val; char __c[1]; } __u = \ - { .__val = (val) }; \ - __write_once_size(&(x), __u.__c, sizeof(x)); \ - __u.__val; \ -}) - -#define READ_ONCE_ARENA(type, x) \ -({ \ - union { type __val; char __c[1]; } __u = \ - { .__c = { 0 } }; \ - __read_once_size((void *)&(x), __u.__c, sizeof(x)); \ - __u.__val; \ +/* + * __unqual_typeof(x) - Declare an unqualified scalar type, leaving + * non-scalar types unchanged, + * + * Prefer C11 _Generic for better compile-times and simpler code. Note: 'char' + * is not type-compatible with 'signed char', and we define a separate case. + * + * This is copied verbatim from kernel's include/linux/compiler_types.h, but + * with default expression (for pointers) changed from (x) to (typeof(x)0). + * + * This is because LLVM has a bug where for lvalue (x), it does not get rid of + * an extra address_space qualifier, but does in case of rvalue (typeof(x)0). + * Hence, for pointers, we need to create an rvalue expression to get the + * desired type. See https://github.com/llvm/llvm-project/issues/53400. + */ +#define __scalar_type_to_expr_cases(type) \ + unsigned type : (unsigned type)0, signed type : (signed type)0 + +#define __unqual_typeof(x) \ + typeof(_Generic((x), \ + char: (char)0, \ + __scalar_type_to_expr_cases(char), \ + __scalar_type_to_expr_cases(short), \ + __scalar_type_to_expr_cases(int), \ + __scalar_type_to_expr_cases(long), \ + __scalar_type_to_expr_cases(long long), \ + default: (typeof(x))0)) + +#define READ_ONCE(x) \ +({ \ + union { __unqual_typeof(x) __val; char __c[1]; } __u = \ + { .__c = { 0 } }; \ + __read_once_size((__unqual_typeof(x) *)&(x), __u.__c, sizeof(x)); \ + __u.__val; \ }) -#define WRITE_ONCE_ARENA(type, x, val) \ -({ \ - union { type __val; char __c[1]; } __u = \ - { .__val = (val) }; \ - __write_once_size((void *)&(x), __u.__c, sizeof(x)); \ - __u.__val; \ +#define WRITE_ONCE(x, val) \ +({ \ + union { __unqual_typeof(x) __val; char __c[1]; } __u = \ + { .__val = (val) }; \ + __write_once_size((__unqual_typeof(x) *)&(x), __u.__c, sizeof(x)); \ + __u.__val; \ }) /* @@ -648,6 +660,23 @@ static inline u32 log2_u64(u64 v) return log2_u32(v) + 1; } +/* + * Return a value proportionally scaled to the task's weight. + */ +static inline u64 scale_by_task_weight(const struct task_struct *p, u64 value) +{ + return (value * p->scx.weight) / 100; +} + +/* + * Return a value inversely proportional to the task's weight. + */ +static inline u64 scale_by_task_weight_inverse(const struct task_struct *p, u64 value) +{ + return value * 100 / p->scx.weight; +} + + #include "compat.bpf.h" #include "enums.bpf.h" |