From mboxrd@z Thu Jan 1 00:00:00 1970 From: maxime.ripard@bootlin.com (Maxime Ripard) Date: Tue, 27 Feb 2018 08:12:11 +0100 Subject: [RFC PATCH] ARM: configs: sunxi: Set ondemand govenor as default In-Reply-To: <15992664-76be-2584-0f8d-424eadc23925@gmail.com> References: <20180217142235.28541-1-embed3d@gmail.com> <20180219081050.vvfhnbw4foved2fb@flea.lan> <15992664-76be-2584-0f8d-424eadc23925@gmail.com> Message-ID: <20180227071211.4c5okbwcp5qjx4ok@flea> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Feb 26, 2018 at 10:29:29PM +0100, Philipp Rossak wrote: > > > On 19.02.2018 09:10, Maxime Ripard wrote: > > On Sat, Feb 17, 2018 at 03:22:35PM +0100, Philipp Rossak wrote: > > > Right now the performance govenor is the default frequency govenor on > > > sunxi devices. This causes some general problems. > > > When the cpu is idle the cpu runs with its maximum frequency. > > > This causes a higher cpu temperature in the idle state. When the cpu is > > > now under load the cpu gets with that higher idle temperature now faster > > > to its thermal limits. > > > An other big problem of the performace govenor is the missing > > > thermal throttling. Some tests with cpuburn resulted in a system crash > > > when the soc reached its thermal limits since no thermal throttling > > > occurred. > > > > This won't change anything with cpuburn. While cpuburn will be > > running, ondemand will increase the frequency of the cores to the > > maximum frequency, putting yourself in the exact same situation. > > I see here a totally different behavior on the hardware (Bananapi M2, A31s). > First ondemand increases the cpu frequency, when the maximum temperature is > reached, then it throttles down the cpu step by step to its minimum. This is the thermal throttling, not the cpufreq governor. Maxime -- Maxime Ripard, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: not available URL: