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| author | Mike Snitzer <snitzer@redhat.com> | 2013-08-20 23:05:17 +0400 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2013-08-23 17:02:14 +0400 |
| commit | eb18cba78c2b9250663021e17e1e9cc34630e92a (patch) | |
| tree | e12eaa9ab3e5fddfd27f7697e7f5b0baf00150e5 /include | |
| parent | f722063ee01c0060488e1000006405449451cfa0 (diff) | |
| download | linux-eb18cba78c2b9250663021e17e1e9cc34630e92a.tar.xz | |
math64: New separate div64_u64_rem helper
Commit f792685006274a850e6cc0ea9ade275ccdfc90bc ("math64: New
div64_u64_rem helper") implemented div64_u64 in terms of div64_u64_rem.
But div64_u64_rem was removed because it slowed down div64_u64 (and
there were no other users of div64_u64_rem).
Device Mapper's I/O statistics support has a need for div64_u64_rem;
reintroduce this helper as a separate method that doesn't slow down
div64_u64, especially on 32-bit systems.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/math64.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/math64.h b/include/linux/math64.h index 2913b86eb12a..69ed5f5e9f6e 100644 --- a/include/linux/math64.h +++ b/include/linux/math64.h @@ -31,6 +31,15 @@ static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder) } /** + * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder + */ +static inline u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder) +{ + *remainder = dividend % divisor; + return dividend / divisor; +} + +/** * div64_u64 - unsigned 64bit divide with 64bit divisor */ static inline u64 div64_u64(u64 dividend, u64 divisor) @@ -63,6 +72,10 @@ static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder); #endif +#ifndef div64_u64_rem +extern u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder); +#endif + #ifndef div64_u64 extern u64 div64_u64(u64 dividend, u64 divisor); #endif |