-----Original Message----- From: ext KOSAKI Motohiro [mailto:kosaki.motohiro@gmail.com] Sent: 08 June, 2012 10:33 To: Moiseichuk Leonid (Nokia-MP/Espoo)
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Wrong. CPU don't realized the running code belong to userspace or kernel. Every code just consume a power. That's why polling timer is wrong from point of power consumption view.
??? We are talking about different things. User-space code could be dropped, distributed between several applications and has not deferred timers support. For polling API the user-space code has to be executed quite often. Localizing this code in kernel additionally allows to avoid vmsat/meminfo generation and parsing overhead as well.