Date: Wed, 8 Sep 2021 01:32:32 GMT From: Colin Percival <cperciva@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 3c253d03d94e - main - Hide acpi_timer_test behind a tunable Message-ID: <202109080132.1881WWPU069824@gitrepo.freebsd.org>
next in thread | raw e-mail | index | archive | help
The branch main has been updated by cperciva: URL: https://cgit.FreeBSD.org/src/commit/?id=3c253d03d94e89cf1a26716b58fc27653df2a4f3 commit 3c253d03d94e89cf1a26716b58fc27653df2a4f3 Author: Colin Percival <cperciva@FreeBSD.org> AuthorDate: 2021-09-07 23:58:18 +0000 Commit: Colin Percival <cperciva@FreeBSD.org> CommitDate: 2021-09-08 01:31:50 +0000 Hide acpi_timer_test behind a tunable When hw.acpi.timer_test_enabled is set to 0, this makes acpi_timer_test return 1 without actually testing the ACPI timer; this results in the ACPI-fast timecounter always being used rather than potentially using ACPI-safe. The ACPI timer testing was introduced in 2002 as a workaround for errata in Pentium II and Pentium III chipsets, and is unlikely to be needed in 2021. While I'm here, add TSENTER/TSEXIT to make it easier to see the time spent on the test (if it is enabled). Reviewed by: allanjude, imp MFC After: 1 week --- sys/dev/acpica/acpi_timer.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/sys/dev/acpica/acpi_timer.c b/sys/dev/acpica/acpi_timer.c index 763a47a1a959..8be6e0edea7f 100644 --- a/sys/dev/acpica/acpi_timer.c +++ b/sys/dev/acpica/acpi_timer.c @@ -79,6 +79,8 @@ static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); static void acpi_timer_boot_test(void); static int acpi_timer_test(void); +static int acpi_timer_test_enabled = 1; +TUNABLE_INT("hw.acpi.timer_test_enabled", &acpi_timer_test_enabled); static device_method_t acpi_timer_methods[] = { DEVMETHOD(device_identify, acpi_timer_identify), @@ -404,6 +406,12 @@ acpi_timer_test() int delta, max, max2, min, n; register_t s; + /* Skip the test based on the hw.acpi.timer_test_enabled tunable. */ + if (!acpi_timer_test_enabled) + return (1); + + TSENTER(); + min = INT32_MAX; max = max2 = 0; @@ -434,6 +442,8 @@ acpi_timer_test() if (bootverbose) printf(" %d/%d", n, delta); + TSEXIT(); + return (n); } #undef N
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202109080132.1881WWPU069824>