-----Original Message----- From: ext Anton Vorontsov [mailto:cbouatmailru@gmail.com] Sent: 08 June, 2012 13:35
...
Context switches, parsing, activity in userspace even memory situation is
not changed.
Sure, there is some additional overhead. I'm just saying that it is not drastic. It would be like 100 sprintfs + 100 sscanfs + 2 context switches? Well, it is unfortunate... but come on, today's phones are running X11 and Java. :-)
Vmstat generation is not so trivial. Meminfo has even higher overhead. I just checked generation time using idling device and open/read test: - vmstat min 30, avg 94 max 2746 uSeconds - meminfo min 30, average 65 max 15961 uSeconds
In comparison /proc/version for the same conditions: min 30, average 41, max 1505 uSeconds
In kernel space you can use sliding timer (increasing interval) + shinker.
Well, w/ Minchan's idea, we can get shrinker notifications into the userland, so the sliding timer thing would be still possible.
Only as a post-schrinker actions. In case of memory stressing or close-to-stressing conditions shrinkers called very often, I saw up to 50 times per second.