Path: csiph.com!goblin2!goblin.stu.neva.ru!aioe.org!bofh.it!news.nic.it!robomod From: Andy Lutomirski Newsgroups: linux.kernel Subject: Re: Skylake (XPS 13 9350) TSC is way off Date: Thu, 03 Dec 2015 01:10:02 +0100 Message-ID: References: X-Original-To: John Stultz X-Gm-Message-State: ALoCoQnl1kTA6VPyQyFN1T7774D2tInsHPW3tlhgwIoq+yz3DRlvx/ADxJUx4/y4jjcN+RHzDmqq X-Received: by 10.182.116.161 with SMTP id jx1mr4391287obb.49.1449100788538; Wed, 02 Dec 2015 15:59:48 -0800 (PST) MIME-Version: 1.0 X-Gmail-Original-Message-ID: Content-Type: text/plain; charset=UTF-8 Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 38 Organization: linux.* mail to news gateway X-Original-Cc: Andy Lutomirski , "Brown, Len" , "linux-kernel@vger.kernel.org" , X86 ML , "Hunter, Adrian" X-Original-Date: Wed, 2 Dec 2015 15:59:28 -0800 X-Original-Message-ID: X-Original-References: <1A7043D5F58CCB44A599DFD55ED4C948469538F6@fmsmsx115.amr.corp.intel.com> X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1282615 On Wed, Dec 2, 2015 at 3:42 PM, John Stultz wrote: > On Wed, Dec 2, 2015 at 3:38 PM, John Stultz wrote: >> On Wed, Dec 2, 2015 at 3:25 PM, Andy Lutomirski wrote: >>> In case it's at all useful, adjtimex -p says: >>> >>> mode: 0 >>> offset: 0 >>> frequency: 135641 >>> maxerror: 37498 >>> esterror: 1532 >>> status: 8192 >>> time_constant: 2 >>> precision: 1 >>> tolerance: 32768000 >>> tick: 10000 >>> raw time: 1449098317s 671243180us = 1449098317.671243180 >>> >>> this suggests a rather small correction, so I really have no idea what >>> "Adjusting tsc more than 11% (8039115 vs 7759462)" means. >>> >>> John, you wrote this code. What does the error message mean? > > Also, is there a behavior issue you're seeing or is this just a > concern about the warning? I assumed it was the first, but digging up > the thread here I'm not sure I see any specific problems listed. No, there's no actual problem I'm aware of other than the error message. Skylake's TSC is different from other chips, and this is Skylake, and I was worried that something was wrong with the initial calibration. It seems like the initial calibration may be fine, though. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/