diff options
Diffstat (limited to 'Documentation/hrtimers.txt')
| -rw-r--r-- | Documentation/hrtimers.txt | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/Documentation/hrtimers.txt b/Documentation/hrtimers.txt index 7620ff7..ce31f65 100644 --- a/Documentation/hrtimers.txt +++ b/Documentation/hrtimers.txt @@ -10,7 +10,7 @@ back and forth trying to integrate high-resolution and high-precision features into the existing timer framework, and after testing various such high-resolution timer implementations in practice, we came to the conclusion that the timer wheel code is fundamentally not suitable for -such an approach. We initially didnt believe this ('there must be a way +such an approach. We initially didn't believe this ('there must be a way to solve this'), and spent a considerable effort trying to integrate things into the timer wheel, but we failed. In hindsight, there are several reasons why such integration is hard/impossible: @@ -27,7 +27,7 @@ several reasons why such integration is hard/impossible: high-res timers. - the unpredictable [O(N)] overhead of cascading leads to delays which - necessiate a more complex handling of high resolution timers, which + necessitate a more complex handling of high resolution timers, which in turn decreases robustness. Such a design still led to rather large timing inaccuracies. Cascading is a fundamental property of the timer wheel concept, it cannot be 'designed out' without unevitably @@ -58,7 +58,7 @@ several reasons why such integration is hard/impossible: The primary users of precision timers are user-space applications that utilize nanosleep, posix-timers and itimer interfaces. Also, in-kernel users like drivers and subsystems which require precise timed events -(e.g. multimedia) can benefit from the availability of a seperate +(e.g. multimedia) can benefit from the availability of a separate high-resolution timer subsystem as well. While this subsystem does not offer high-resolution clock sources just @@ -68,7 +68,7 @@ The increasing demand for realtime and multimedia applications along with other potential users for precise timers gives another reason to separate the "timeout" and "precise timer" subsystems. -Another potential benefit is that such a seperation allows even more +Another potential benefit is that such a separation allows even more special-purpose optimization of the existing timer wheel for the low resolution and low precision use cases - once the precision-sensitive APIs are separated from the timer wheel and are migrated over to @@ -96,8 +96,8 @@ file systems. The rbtree is solely used for time sorted ordering, while a separate list is used to give the expiry code fast access to the queued timers, without having to walk the rbtree. -(This seperate list is also useful for later when we'll introduce -high-resolution clocks, where we need seperate pending and expired +(This separate list is also useful for later when we'll introduce +high-resolution clocks, where we need separate pending and expired queues while keeping the time-order intact.) Time-ordered enqueueing is not purely for the purposes of |
