On 9/8/21 9:01 AM, John Baldwin wrote: > On 9/7/21 6:32 PM, Colin Percival wrote: >> Disable acpi_timer_test by default >> This disables testing the ACPI timer by default, forcing the use of >> ACPI-fast rather than ACPI-safe. The broken-ACPI-timers workaround >> can be re-enabled by setting the hw.acpi.timer_test_enabled=1 tunable. >> This speeds up the FreeBSD boot process by 140 ms on an EC2 >> c5.xlarge >> instance. >> This change will not be MFCed. >> Assuming no problems are reported, acpi_timer_test, the associated >> tunable, and the ACPI-safe timecounter should be removed in FreeBSD 15. >> Relnotes: The ACPI-safe timer is disabled in favour of >> ACPI-fast; >> if timekeeping issues are observed, please test with >> hw.acpi.timer_test_enabled=1 in loader.conf and report >> if that fixes the problem. > > Perhaps it should default to '1' for i386 and '0' otherwise? The relevant > chipsets were 32-bit only, so this would be a simple way to skip the test for > modern hardware, and you could probably MFC that safely.
That option was discussed, but I decided that it was probably safer to keep it enabled by default in 13 in case the test was detecting systems which are broken in other ways. Googling for "ACPI-safe" (which shows up if the test fails) finds forum discussions from the mid-2010s, but it's not clear whether that's due to very old hardware, new ACPI timer issues, or other timekeeping problems -- I figured it was best to play it safe for something which would be going into a stable branch though. -- Colin Percival Security Officer Emeritus, FreeBSD | The power to serve Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid _______________________________________________ dev-commits-src-main@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/dev-commits-src-main To unsubscribe, send any mail to "dev-commits-src-main-unsubscr...@freebsd.org"
