From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Wed, 06 May 2026 09:42:19 +0200 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1wKWtg-001WIV-0g for lore@lore.pengutronix.de; Wed, 06 May 2026 09:42:19 +0200 Received: from [127.0.0.1] (helo=metis.whiteo.stw.pengutronix.de) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1wKWte-0005tJ-Ve; Wed, 06 May 2026 09:42:18 +0200 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1wKWtb-0005sw-2n; Wed, 06 May 2026 09:42:15 +0200 Received: from pty.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::c5]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1wKWta-000hrW-1T; Wed, 06 May 2026 09:42:14 +0200 Received: from mol by pty.whiteo.stw.pengutronix.de with local (Exim 4.98.2) (envelope-from ) id 1wKWta-00000003QO7-3KXs; Wed, 06 May 2026 09:42:14 +0200 Date: Wed, 6 May 2026 09:42:14 +0200 From: Michael Olbrich To: Ahmad Fatoum Message-ID: Mail-Followup-To: Ahmad Fatoum , Lucas Stach , distrokit@pengutronix.de References: <20260505111714.1361551-1-l.stach@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-IRC: #ptxdist @freenode Subject: Re: [DistroKit] [PATCH v3 1/4] x86_64: kernel: update config X-BeenThere: distrokit@pengutronix.de X-Mailman-Version: 2.1.29 Precedence: list List-Id: DistroKit Mailinglist List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: distrokit@pengutronix.de, Lucas Stach Sender: "DistroKit" X-SA-Exim-Connect-IP: 127.0.0.1 X-SA-Exim-Mail-From: distrokit-bounces@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false On Tue, May 05, 2026 at 01:33:56PM +0200, Ahmad Fatoum wrote: > On 5/5/26 1:17 PM, Lucas Stach wrote: > > CONFIG_UTS_NS=y > > -CONFIG_TIME_NS=y > > +# CONFIG_TIME_NS is not set > > Just spitballing here: With an eye towards Y2038, do we maybe want to > keep this enabled? > > - Positive Offset: Enable isolated testing of components with y2038 time > - Negative Offset: Run proprietary components that were't fixed in the past? I think this can be enabled when needed. If you try to use it, and it's not enabled the you will get a failure, so there should be no silent failures. > > +CONFIG_INITRAMFS_PRESERVE_MTIME=y > > FWIW, I normally disable this as this is just extra work that I don't > see the need for in my BSPs. > > Quoting 1274aea127b2 ("initramfs: add INITRAMFS_PRESERVE_MTIME Kconfig > option"): > > """ > This change adds a new INITRAMFS_PRESERVE_MTIME Kconfig option, which > can be used to disable on-by-default mtime retention and in turn speed > up initramfs extraction, particularly for cpio archives with large > directory counts. > > Benchmarks with a one million directory cpio archive extracted 20 times > demonstrated: > mean extraction time (s) std dev > INITRAMFS_PRESERVE_MTIME=y 3.808 0.006 > INITRAMFS_PRESERVE_MTIME unset 3.056 0.004 > """ > > Granted my initramfs are probably not big enough to matter, but still > why do the extra work? Makes sense to me. > > -CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y > > +# CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE is not set > > # CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE is not set > > # CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE is not set > > -# CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL is not set > > +CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL=y > > The thinking so far was that performance gives us the best boot time and > then we would switch to a more suitable default from userspace. > > Is this outdated practice? That would require switching at runtime. And a lot of BSP, including DistroKit, don't actually do it. And in that case defaulting to performance is a bad idea. I'd rather have a save default. If someone cares about the extra speedup then they will actually look at the option anyways and can change it. Michael -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |