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| author | Michal Marek <mmarek@suse.cz> | 2014-01-02 14:02:06 +0100 |
|---|---|---|
| committer | Michal Marek <mmarek@suse.cz> | 2014-01-02 14:02:06 +0100 |
| commit | 37e2c2a775fc887acd1432908478dfd532f7f00f (patch) | |
| tree | e51ebc699d8e262fd47e0913be6a711cb1a7b565 /include/net/codel.h | |
| parent | 1c8ddae09f4c102b97c9086cc70347e89468a547 (diff) | |
| parent | 6ce4eac1f600b34f2f7f58f9cd8f0503d79e42ae (diff) | |
| download | lwn-37e2c2a775fc887acd1432908478dfd532f7f00f.tar.gz lwn-37e2c2a775fc887acd1432908478dfd532f7f00f.zip | |
Merge commit v3.13-rc1 into kbuild/misc
Diffstat (limited to 'include/net/codel.h')
| -rw-r--r-- | include/net/codel.h | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/include/net/codel.h b/include/net/codel.h index 389cf621161d..3b04ff5f6f8d 100644 --- a/include/net/codel.h +++ b/include/net/codel.h @@ -72,10 +72,21 @@ static inline codel_time_t codel_get_time(void) return ns >> CODEL_SHIFT; } -#define codel_time_after(a, b) ((s32)(a) - (s32)(b) > 0) -#define codel_time_after_eq(a, b) ((s32)(a) - (s32)(b) >= 0) -#define codel_time_before(a, b) ((s32)(a) - (s32)(b) < 0) -#define codel_time_before_eq(a, b) ((s32)(a) - (s32)(b) <= 0) +/* Dealing with timer wrapping, according to RFC 1982, as desc in wikipedia: + * https://en.wikipedia.org/wiki/Serial_number_arithmetic#General_Solution + * codel_time_after(a,b) returns true if the time a is after time b. + */ +#define codel_time_after(a, b) \ + (typecheck(codel_time_t, a) && \ + typecheck(codel_time_t, b) && \ + ((s32)((a) - (b)) > 0)) +#define codel_time_before(a, b) codel_time_after(b, a) + +#define codel_time_after_eq(a, b) \ + (typecheck(codel_time_t, a) && \ + typecheck(codel_time_t, b) && \ + ((s32)((a) - (b)) >= 0)) +#define codel_time_before_eq(a, b) codel_time_after_eq(b, a) /* Qdiscs using codel plugin must use codel_skb_cb in their own cb[] */ struct codel_skb_cb { |