Date: Mon, 20 Feb 2017 10:25:48 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 217247] [acpi] r265474 makes 11.0R unusable with Atom 330 Message-ID: <bug-217247-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=217247 Bug ID: 217247 Summary: [acpi] r265474 makes 11.0R unusable with Atom 330 Product: Base System Version: 11.0-RELEASE Hardware: amd64 OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: stephane_freebsd@lesimple.fr After upgrading my FreeBSD-based firewall from 10.3R to 11.0R, the boot time (from power-on to the login prompt) rocketed from ~1 minute to more than 45 minutes, and even when up, the system was extremely slow. The loadavg was >2, with no process really taking that much CPU time, and the number of IRQ was not too high (200-300 per sec) even if 20% of the time was spent in IRQ. To rule out any oddity with my system config, I reproduced the problem with the bare official FreeBSD-10.3-RELEASE-amd64-memstick.img where the kernel takes 20s to boot, and FreeBSD-11.0-RELEASE-amd64-memstick.img takes more than 8 minutes, from "Booting..." to the login prompt. So, it took me several days of manual bisecting-compiling-memstick-booting, and I finally found the culprit: base r265474 The diff is pretty straightforward, in /etc/defaults/rc.conf: -performance_cx_lowest="HIGH" # Online CPU idle state +performance_cx_lowest="Cmax" # Online CPU idle state -economy_cx_lowest="HIGH" # Offline CPU idle state +economy_cx_lowest="Cmax" # Offline CPU idle state If I override these values by putting HIGH back in /etc/rc.conf.local, the problem disappears. I was able to manually confirm that if I set dev.cpu.N.cx_lowest to C2 (or C3), the system is horribly slow and sluggish, and back to C1 ("HIGH"), it's usable again. The commit message indicates that "This may not stay through 11.0-RELEASE, but at least having it on by default in -HEAD will expose (more) issues with broken hardware", so I guess my hardware is broken, even if I didn't observe such behavior previously under other OSes (namely Linux). I can imagine that anybody else booting FreeBSD 11.0 under such hardware would just give up, so it might be a good idea to detect this CPU on install and keep cx_lowest at C1? root@fw:~ # sysctl hw.machine hw.model dev.cpu.0 hw.machine: amd64 hw.model: Intel(R) Atom(TM) CPU 330 @ 1.60GHz dev.cpu.0.cx_method: C1/hlt C2/io C3/io dev.cpu.0.cx_usage_counters: 10731 0 0 dev.cpu.0.cx_usage: 100.00% 0.00% 0.00% last 4432us dev.cpu.0.cx_lowest: C1 dev.cpu.0.cx_supported: C1/1/0 C2/2/1 C3/3/85 dev.cpu.0.%parent: acpi0 dev.cpu.0.%pnpinfo: _HID=none _UID=0 dev.cpu.0.%location: handle=\_PR_.P001 dev.cpu.0.%driver: cpu dev.cpu.0.%desc: ACPI CPU -- You are receiving this mail because: You are the assignee for the bug.
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