From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753037AbeBIVNr (ORCPT ); Fri, 9 Feb 2018 16:13:47 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:49570 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752905AbeBIVNC (ORCPT ); Fri, 9 Feb 2018 16:13:02 -0500 From: Pavel Tatashin To: steven.sistare@oracle.com, daniel.m.jordan@oracle.com, linux@armlinux.org.uk, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, john.stultz@linaro.org, sboyd@codeaurora.org, x86@kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com, douly.fnst@cn.fujitsu.com, peterz@infradead.org, prarit@redhat.com Subject: [PATCH v10 0/7] Early boot time stamps for x86 Date: Fri, 9 Feb 2018 16:11:36 -0500 Message-Id: <20180209211143.16215-1-pasha.tatashin@oracle.com> X-Mailer: git-send-email 2.16.1 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8800 signatures=668666 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1802090267 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org changelog --------- v10 - v9 - Added another patch to this series that removes dependency between KVM clock, and memblock allocator. The benefit is that all clocks can now be initialized even earlier. v9 - v8 - Addressed more comments from Dou Liyang v8 - v7 - Addressed comments from Dou Liyang: - Moved tsc_early_init() and tsc_early_fini() to be all inside tsc.c, and changed them to be static. - Removed warning when notsc parameter is used. - Merged with: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git v7 - v6 - Removed tsc_disabled flag, now notsc is equivalent of tsc=unstable - Simplified changes to sched/clock.c, by removing the sched_clock_early() and friends as requested by Peter Zijlstra. We know always use sched_clock() - Modified x86 sched_clock() to return either early boot time or regular. - Added another example why ealry boot time is important v5 - v6 - Added a new patch: time: sync read_boot_clock64() with persistent clock Which fixes missing __init macro, and enabled time discrepancy fix that was noted by Thomas Gleixner - Split "x86/time: read_boot_clock64() implementation" into a separate patch v4 - v5 - Fix compiler warnings on systems with stable clocks. v3 - v4 - Fixed tsc_early_fini() call to be in the 2nd patch as reported by Dou Liyang - Improved comment before __use_sched_clock_early to explain why we need both booleans. - Simplified valid_clock logic in read_boot_clock64(). v2 - v3 - Addressed comment from Thomas Gleixner - Timestamps are available a little later in boot but still much earlier than in mainline. This significantly simplified this work. v1 - v2 In patch "x86/tsc: tsc early": - added tsc_adjusted_early() - fixed 32-bit compile error use do_div() Adding early boot time stamps support for x86 machines. SPARC patches for early boot time stamps are already integrated into mainline linux. Sample output ------------- Before: https://paste.ubuntu.com/26133428/ After: https://paste.ubuntu.com/26133523/ For exaples how early time stamps are used, see this work: Example 1: https://lwn.net/Articles/734374/ - Without early boot time stamps we would not know about the extra time that is spent zeroing struct pages early in boot even when deferred page initialization. Example 2: https://patchwork.kernel.org/patch/10021247/ - If early boot timestamps were available, the engineer who introduced this bug would have noticed the extra time that is spent early in boot. Pavel Tatashin (7): x86/tsc: remove tsc_disabled flag time: sync read_boot_clock64() with persistent clock x86/time: read_boot_clock64() implementation sched: early boot clock x86/paravirt: add active_sched_clock to pv_time_ops x86/tsc: use tsc early kvm/x86: remove kvm memblock dependency arch/arm/kernel/time.c | 2 +- arch/s390/kernel/time.c | 2 +- arch/x86/include/asm/paravirt.h | 2 +- arch/x86/include/asm/paravirt_types.h | 1 + arch/x86/kernel/kvm.c | 1 + arch/x86/kernel/kvmclock.c | 64 +++---------------- arch/x86/kernel/paravirt.c | 1 + arch/x86/kernel/setup.c | 7 +- arch/x86/kernel/time.c | 30 +++++++++ arch/x86/kernel/tsc.c | 117 ++++++++++++++++++++++++++++------ arch/x86/xen/time.c | 7 +- include/linux/timekeeping.h | 3 +- kernel/sched/clock.c | 10 ++- kernel/time/timekeeping.c | 8 ++- 14 files changed, 164 insertions(+), 91 deletions(-) -- 2.16.1