From owner-dev-commits-src-main@freebsd.org Thu Jan 21 12:58:09 2021 Return-Path: Delivered-To: dev-commits-src-main@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 0AC294F4994; Thu, 21 Jan 2021 12:58:09 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4DM2W46wjnz3sFV; Thu, 21 Jan 2021 12:58:08 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id E0D5D41F8; Thu, 21 Jan 2021 12:58:08 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 10LCw89Q053594; Thu, 21 Jan 2021 12:58:08 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 10LCw8PA053593; Thu, 21 Jan 2021 12:58:08 GMT (envelope-from git) Date: Thu, 21 Jan 2021 12:58:08 GMT Message-Id: <202101211258.10LCw8PA053593@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Konstantin Belousov Subject: git: 9f47eeffa3cf - main - x86: switch kernel TSC timecounter to RDTSCP on AMD Zen CPUs MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kib X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 9f47eeffa3cfdcb512e2011fb00fc23c7c1a7d75 Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-main@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for the main branch of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 21 Jan 2021 12:58:09 -0000 The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=9f47eeffa3cfdcb512e2011fb00fc23c7c1a7d75 commit 9f47eeffa3cfdcb512e2011fb00fc23c7c1a7d75 Author: Konstantin Belousov AuthorDate: 2021-01-21 12:53:15 +0000 Commit: Konstantin Belousov CommitDate: 2021-01-21 12:55:31 +0000 x86: switch kernel TSC timecounter to RDTSCP on AMD Zen CPUs Reported by: many Tested by: gallatin, mikael, rhurlin MFC after: 1 week Sponsored by: The FreeBSD Foundation --- sys/x86/x86/tsc.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/sys/x86/x86/tsc.c b/sys/x86/x86/tsc.c index 85924df98312..de0a1505c2f6 100644 --- a/sys/x86/x86/tsc.c +++ b/sys/x86/x86/tsc.c @@ -633,19 +633,12 @@ init: /* * Timecounter implementation selection, top to bottom: - * - For AMD Zens and newer, use LFENCE;RDTSC. * - If RDTSCP is available, use RDTSCP. * - If fence instructions are provided (SSE2), use LFENCE;RDTSC * on Intel, and MFENCE;RDTSC on AMD. * - For really old CPUs, just use RDTSC. */ - if ((cpu_vendor_id == CPU_VENDOR_AMD || - cpu_vendor_id == CPU_VENDOR_HYGON) && - CPUID_TO_FAMILY(cpu_id) >= 0x17) { - tsc_timecounter.tc_get_timecount = shift > 0 ? - tsc_get_timecount_low_lfence : - tsc_get_timecount_lfence; - } else if ((amd_feature & AMDID_RDTSCP) != 0) { + if ((amd_feature & AMDID_RDTSCP) != 0) { tsc_timecounter.tc_get_timecount = shift > 0 ? tscp_get_timecount_low : tscp_get_timecount; } else if ((cpu_feature & CPUID_SSE2) != 0 && mp_ncpus > 1) {