From 84eaf2ccc6aa05da7b7389991d3023698b756e3f Mon Sep 17 00:00:00 2001 From: Konstantin Belousov Date: Mon, 21 Dec 2020 19:02:31 +0200 Subject: [PATCH] x86: stop punishing VMs with low priority for TSC timecounter I suspect that virtualization techniques improved from the time when we have to effectively disable TSC use in VM. For instance, it was reported (complained) in https://github.com/JuliaLang/julia/issues/38877 that FreeBSD is groundlessly slow on AWS with some loads. Remove the check and start watching for complaints. Reviewed by: emaste, grehan Discussed with: cperciva Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D27629 --- sys/x86/x86/tsc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sys/x86/x86/tsc.c b/sys/x86/x86/tsc.c index c8e9be0c3cd5..6b5242fb5d4f 100644 --- a/sys/x86/x86/tsc.c +++ b/sys/x86/x86/tsc.c @@ -499,7 +499,7 @@ test_tsc(int adj_max_count) uint64_t *data, *tsc; u_int i, size, adj; - if ((!smp_tsc && !tsc_is_invariant) || vm_guest) + if ((!smp_tsc && !tsc_is_invariant)) return (-100); size = (mp_maxid + 1) * 3; data = malloc(sizeof(*data) * size * N, M_TEMP, M_WAITOK);