From: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
To: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
peterz@infradead.org, Steven Sistare <steven.sistare@oracle.com>,
Daniel Jordan <daniel.m.jordan@oracle.com>,
linux@armlinux.org.uk, schwidefsky@de.ibm.com,
Heiko Carstens <heiko.carstens@de.ibm.com>,
John Stultz <john.stultz@linaro.org>,
sboyd@codeaurora.org, x86@kernel.org,
LKML <linux-kernel@vger.kernel.org>,
mingo@redhat.com, hpa@zytor.com, douly.fnst@cn.fujitsu.com,
prarit@redhat.com, feng.tang@intel.com,
Petr Mladek <pmladek@suse.com>,
linux-s390@vger.kernel.org, boris.ostrovsky@oracle.com,
jgross@suse.com, pbonzini@redhat.com
Subject: Re: [PATCH v14 20/25] x86/tsc: calibrate tsc only once
Date: Mon, 23 Jul 2018 10:28:41 +0100 [thread overview]
Message-ID: <20180723102841.58ea373b@alans-desktop> (raw)
In-Reply-To: <ae3e5320-b389-e8af-2905-1ccc37953da3@oracle.com>
> >> If we determined tsc early in boot using one of the quick methods:
> >> from cpuid/msr/quick_pit, can we assume that frequencies of all other
> >> CPUs will be determined the same way? Or do we still have to fallback
Not on 32bit at least. You can have a mixed slot 1 SMP system such as
an ASUS BP6 with cores at say 300 and 450MHz.
Now whether you'll find any such system in the world today is another
question.
Alan
next prev parent reply other threads:[~2018-07-23 9:29 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-18 2:21 [PATCH v14 00/25] Early boot time stamps Pavel Tatashin
2018-07-18 2:21 ` [PATCH v14 01/25] x86/kvmclock: Remove memblock dependency Pavel Tatashin
2018-07-18 2:21 ` [PATCH v14 02/25] x86/kvmclock: Remove page size requirement from wall_clock Pavel Tatashin
2018-07-18 2:21 ` [PATCH v14 03/25] x86/kvmclock: Decrapify kvm_register_clock() Pavel Tatashin
2018-07-18 2:21 ` [PATCH v14 04/25] x86/kvmclock: Cleanup the code Pavel Tatashin
2018-07-18 2:21 ` [PATCH v14 05/25] x86/kvmclock: Mark variables __initdata and __ro_after_init Pavel Tatashin
2018-07-18 2:21 ` [PATCH v14 06/25] x86/kvmclock: Move kvmclock vsyscall param and init to kvmclock Pavel Tatashin
2018-07-18 2:21 ` [PATCH v14 07/25] x86/kvmclock: Switch kvmclock data to a PER_CPU variable Pavel Tatashin
2018-07-18 2:21 ` [PATCH v14 08/25] x86/kvmclock: Avoid TSC recalibration Pavel Tatashin
2018-07-18 11:14 ` Paolo Bonzini
2018-07-18 13:33 ` Pavel Tatashin
2018-07-18 2:21 ` [PATCH v14 09/25] x86: text_poke() may access uninitialized struct pages Pavel Tatashin
2018-07-18 2:21 ` [PATCH v14 10/25] x86: initialize static branching early Pavel Tatashin
2018-07-18 2:21 ` [PATCH v14 11/25] x86/CPU: Call detect_nopl() only on the BSP Pavel Tatashin
2018-07-18 2:21 ` [PATCH v14 12/25] x86/tsc: redefine notsc to behave as tsc=unstable Pavel Tatashin
2018-07-18 2:21 ` [PATCH v14 13/25] x86/xen/time: initialize pv xen time in init_hypervisor_platform Pavel Tatashin
2018-07-18 2:22 ` [PATCH v14 14/25] x86/xen/time: output xen sched_clock time from 0 Pavel Tatashin
2018-07-18 2:22 ` [PATCH v14 15/25] s390/time: add read_persistent_wall_and_boot_offset() Pavel Tatashin
2018-07-18 2:22 ` [PATCH v14 16/25] time: replace read_boot_clock64() with read_persistent_wall_and_boot_offset() Pavel Tatashin
2018-07-18 2:22 ` [PATCH v14 17/25] time: default boot time offset to local_clock() Pavel Tatashin
2018-07-18 2:22 ` [PATCH v14 18/25] s390/time: remove read_boot_clock64() Pavel Tatashin
2018-07-18 2:22 ` [PATCH v14 19/25] ARM/time: " Pavel Tatashin
2018-07-18 2:22 ` [PATCH v14 20/25] x86/tsc: calibrate tsc only once Pavel Tatashin
2018-07-19 5:33 ` Dou Liyang
2018-07-19 6:25 ` Thomas Gleixner
2018-07-19 6:48 ` Dou Liyang
2018-07-19 10:33 ` Peter Zijlstra
2018-07-19 11:01 ` Thomas Gleixner
2018-07-19 15:58 ` Pavel Tatashin
2018-07-19 16:19 ` Thomas Gleixner
2018-07-19 16:49 ` Pavel Tatashin
2018-07-19 18:38 ` Pavel Tatashin
2018-07-19 20:44 ` Thomas Gleixner
2018-07-19 20:46 ` Pavel Tatashin
2018-07-23 9:28 ` Alan Cox [this message]
2018-07-18 2:22 ` [PATCH v14 21/25] x86/tsc: initialize cyc2ns when tsc freq. is determined Pavel Tatashin
2018-07-18 2:22 ` [PATCH v14 22/25] x86/tsc: use tsc early Pavel Tatashin
2018-07-18 2:22 ` [PATCH v14 23/25] sched: move sched clock initialization and merge with generic clock Pavel Tatashin
2018-07-18 2:22 ` [PATCH v14 24/25] sched: early boot clock Pavel Tatashin
2018-07-19 10:39 ` Peter Zijlstra
2018-07-19 14:16 ` Pavel Tatashin
2018-07-18 2:22 ` [PATCH v14 25/25] sched: use static key for sched_clock_running Pavel Tatashin
2018-07-19 10:48 ` Peter Zijlstra
2018-07-19 14:24 ` Pavel Tatashin
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