(Sorry for the spam. I am resending the series because I noted that some of the email addresses were mistyped) Currently main mechanism to implement scaling using devfreq is polling and the device profile is free to set polling interval. However, in many cases this approach is not optimal; We may unnecessarily use CPU time to determine load on engine that is idle most of time - or we may simply read load when we already know that the device is busy. In some cases a device itself has counters to track its activity and possibility to raise interrupts when load goes above or below certain threshold. This series adds support for watermark events to devfreq and introduces two example governors. The first patch adds two callbacks to the device profile (for setting watermark) and adds a new function call to devfreq that informs of crossed watermark. The added governors demonstrate usage of the new API. The first governor (watermark simple) sets device to trigger low watermark event when load goes below 10% and high watermark interrupt when the load goes above 60%. Watermark active tries to keep load at certain level and it actively sets thresholds based on the frequency table in order get interrupts only when the load value would affect to the current frequency in re-estimation. Arto Merilainen (1): PM / devfreq: Add watermark active governor Shridhar Rasal (2): PM / devfreq: Add watermark events PM / devfreq: Add watermark simple governor drivers/devfreq/Kconfig | 18 +++ drivers/devfreq/Makefile | 2 + drivers/devfreq/devfreq.c | 19 +++ drivers/devfreq/governor.h | 1 + drivers/devfreq/governor_wmark_active.c | 276 ++++++++++++++++++++++++++++++++ drivers/devfreq/governor_wmark_simple.c | 245 ++++++++++++++++++++++++++++ include/linux/devfreq.h | 26 +++ 7 files changed, 587 insertions(+) create mode 100644 drivers/devfreq/governor_wmark_active.c create mode 100644 drivers/devfreq/governor_wmark_simple.c -- 1.8.1.5 -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
