972256 - [Tarako] low memory killer tuning

Status: RESOLVED DUPLICATE of bug 972130

(Firefox OS Graveyard :: General, defect)

Description

[Danny Liang [:dliang]]

For the low memory device like Tarako, we need to discuss about memory setting for better performance. I summarize the current setting and problem as below. 

The current specific memory setting on tarako as below:
pref("hal.processPriorityManager.gonk.enableOOBPKiller", true);
pref("hal.processPriorityManager.gonk.MASTER.KillUnderMB", 1);
pref("hal.processPriorityManager.gonk.FOREGROUND_HIGH.KillUnderMB", 2);
pref("hal.processPriorityManager.gonk.FOREGROUND.KillUnderMB", 4);
pref("hal.processPriorityManager.gonk.BACKGROUND_PERCEIVABLE.KillUnderMB", 6);
pref("hal.processPriorityManager.gonk.BACKGROUND.KillUnderMB", 20);
pref("hal.processPriorityManager.gonk.notifyLowMemUnderMB", 10);

1. If BACKGROUND.KillUnderMB is lower than 20MB, the performance of launch application is worse.
2. With above setting, the memory pressure events are hard to be trigger due to free+cache is usually higher than 20MB.
3. If notifyLowMemUnderMB is higher, there might be many memory pressure events and it will let performance bad.