diff options
| author | Srivatsa Vaddagiri <vatsa@codeaurora.org> | 2014-04-29 12:44:43 -0700 |
|---|---|---|
| committer | David Keitel <dkeitel@codeaurora.org> | 2016-03-23 19:59:16 -0700 |
| commit | 33e71001037326b76c5fc0764167afd6f03285d5 (patch) | |
| tree | 82d4b15172a903b00848239cc193fcdb2c6847a4 /include/linux | |
| parent | 490b1d23cc0c905b1cfb722ece7291a6d3a0f87e (diff) | |
sched: window-stats: synchronize windows across cpus
Synchronizing windows across cpus for task load measurements
simplifies cpu busy time accounting during migrations. For task
migrations, its usage in current window can be carried over to its new
cpu. This lets cpufreq governor see a correct picture of cpu busy time
that is not affected by migrations.
This patch lines up windows across cpus. One of the cpu, sync_cpu,
serves as a reference for all others. During bootup sync_cpu would
initialize its window_start (from its sched_clock()). Other cpus will
synchronize their window_start in reference to sync_cpu. This patch
assumes synchronous sched_clock() across cpus and may need some change
to address architectures which do not provide such synchronized
sched_clock().
Change-Id: I13381389a72f5f9f85cc2446401d493a55c78ab7
Signed-off-by: Steve Muckle <smuckle@codeaurora.org>
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/sched.h | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 5cdba398f367..74977547700f 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1249,8 +1249,6 @@ struct sched_statistics { /* ravg represents frequency scaled cpu-demand of tasks */ struct ravg { /* - * 'window_start' marks the beginning of new window - * * 'mark_start' marks the beginning of an event (task waking up, task * starting to execute, task being preempted) within a window * @@ -1265,7 +1263,7 @@ struct ravg { * 'demand' represents maximum sum seen over previous RAVG_HIST_SIZE * windows. 'demand' could drive frequency demand for tasks. */ - u64 window_start, mark_start; + u64 mark_start; u32 sum, demand; u32 sum_history[RAVG_HIST_SIZE]; }; |