From nobody Sun Jan 02 21:08:08 2022 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 45AEA19202E5; Sun, 2 Jan 2022 21:08:10 +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 4JRs0n2wv9z3L5W; Sun, 2 Jan 2022 21:08:09 +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 165FD190A8; Sun, 2 Jan 2022 21:08:09 +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 202L88Yr018206; Sun, 2 Jan 2022 21:08:08 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 202L88eB018205; Sun, 2 Jan 2022 21:08:08 GMT (envelope-from git) Date: Sun, 2 Jan 2022 21:08:08 GMT Message-Id: <202201022108.202L88eB018205@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Colin Percival Subject: git: 9cb3288287ba - main - Skip TSC calibration if exact value known List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-all@freebsd.org X-BeenThere: dev-commits-src-all@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: cperciva X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 9cb3288287ba1b3c1d0ec891c552fc4b9472027e Auto-Submitted: auto-generated ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1641157689; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=c6zr2g7gIk3/rT1u5jDQbNn/ubFHM19U3abJOjcQiI0=; b=OGgKpSsY/f3k0utIdElu1z4L8kO1yDkOFKbALetpvj8OSu6dc9LsKQRLE+ee3dj5xu41Cd FZR2Yz/znAXxW/I4DMIg17RIY9MachalAA2FIQvLuAigHUBkZDuadl8n82JqJIgGz8GdK6 3TKotIkdt5mwftpM6AKGdYgVLGcEiKfa5scMFU3VY0gBsl5McEja52Y4luNlljq0VjUpC5 3D5iiKqZjV31lBqfHxWKdUZjlKmall4JPI6bYQ3+8D3MROUQZH/7nW0zSTGN6raLp1FEIY tUrOQa9QIGD+uBvayi5Lu1AjImtP7szvGmZhOxyHI/2cbswxVVNY21fXsJyGbg== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1641157689; a=rsa-sha256; cv=none; b=nJxXo8PPpL/RGHB2e8/qBNJPeZU6FyA/UTgRIV0RT8iRd5cKqge5BZsgWl0Cl+ArWLkxng uwAnV72lZKeqNYAlk2deO4ApwerDnD/Q37hw9GfIp03Trg7D3qyyU3LpzF/IZAmRq5B25c 8LOo9oH4+d3IsmhBERcNg34g0R88hC5JrlvxvJh2LfKBrogI949ra7KSx5ieJ6xlZPrFZM 42+NKWi43OQfgx6DEnBrgASQXq0+5sf3r/S7EmDBW99AJxFBrQCwcO6uYXph9po0wZ3rem yTJe9sOEWqeFZFgGHjpxESIzMByYKjuk3LZth4tOpT69p5VYOYt8q6Ehem1Tbg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N The branch main has been updated by cperciva: URL: https://cgit.FreeBSD.org/src/commit/?id=9cb3288287ba1b3c1d0ec891c552fc4b9472027e commit 9cb3288287ba1b3c1d0ec891c552fc4b9472027e Author: Colin Percival AuthorDate: 2021-12-30 19:43:15 +0000 Commit: Colin Percival CommitDate: 2022-01-02 21:07:53 +0000 Skip TSC calibration if exact value known It's possible that the "early" TSC calibration gave us a value which is known to be exact; in that case, skip the later re-calibration. MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D33695 --- sys/x86/x86/tsc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/sys/x86/x86/tsc.c b/sys/x86/x86/tsc.c index ab8f94c2fc2d..534fdb5dd279 100644 --- a/sys/x86/x86/tsc.c +++ b/sys/x86/x86/tsc.c @@ -59,6 +59,7 @@ __FBSDID("$FreeBSD$"); uint64_t tsc_freq; int tsc_is_invariant; int tsc_perf_stat; +static int tsc_early_calib_exact; static eventhandler_tag tsc_levels_tag, tsc_pre_tag, tsc_post_tag; @@ -133,6 +134,7 @@ tsc_freq_vmware(void) tsc_freq = regs[0] | ((uint64_t)regs[1] << 32); } tsc_is_invariant = 1; + tsc_early_calib_exact = 1; } /* @@ -709,6 +711,8 @@ tsc_calibrate(void) if (tsc_disabled) return; + if (tsc_early_calib_exact) + goto calibrated; tc = atomic_load_ptr(&timecounter); @@ -739,6 +743,7 @@ tsc_calibrate(void) freq_khz = tc->tc_frequency * (tsc_end - tsc_start) / (t_end - t_start); tsc_update_freq(freq_khz); +calibrated: tc_init(&tsc_timecounter); set_cputicker(rdtsc, tsc_freq, !tsc_is_invariant); }