From mboxrd@z Thu Jan 1 00:00:00 1970 From: juri.lelli@arm.com (Juri Lelli) Date: Tue, 19 Jan 2016 14:29:33 +0000 Subject: [RFC PATCH v2 0/4] CPUs capacity information for heterogeneous systems In-Reply-To: <20160119112323.GB8573@e106622-lin> References: <1452262172-31861-1-git-send-email-juri.lelli@arm.com> <56994D87.6000709@linaro.org> <20160118151316.GD7159@e106622-lin> <20160118163014.GA10332@e106622-lin> <20160119105941.GA28845@e104818-lin.cambridge.arm.com> <20160119112323.GB8573@e106622-lin> Message-ID: <20160119142933.GF8573@e106622-lin> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 19/01/16 11:23, Juri Lelli wrote: > Hi Catalin, > > On 19/01/16 10:59, Catalin Marinas wrote: > > On Mon, Jan 18, 2016 at 05:42:58PM +0100, Vincent Guittot wrote: > > > On 18 January 2016 at 17:30, Juri Lelli wrote: > > > > On 18/01/16 17:13, Vincent Guittot wrote: > > > >> On 18 January 2016 at 16:13, Juri Lelli wrote: > > > >> > On 15/01/16 11:50, Steve Muckle wrote: > > > >> >> On 01/08/2016 06:09 AM, Juri Lelli wrote: [...] > > > > Two questions: > > > > 1. How is the boot time affected by the benchmark? > > 2. How is the boot time affected by considering all the CPUs the same? > > > > My preference is for DT and sysfs (especially useful for > > development/tuning) but I'm not opposed to a boot-time benchmark if > > people insist on it. If the answer to point 2 is "insignificant", we > > could as well defer the capacity setting to user space (sysfs). > > > > Given that we are not targeting boot time with this, but rather better > performance afterwards, I don't expect significant differences; but, > I'll get numbers :). > I've got some boot time numbers on TC2 and Juno based on timestamps. They are of course not accurate and maybe not so representative of products, but I guess still ballpark right. I'm generally seeing ~1sec increase in boot time for 1 and practically no difference for 2 (even after having added patches that provide runtime performance improvements). Best, - Juri