From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C2E6C64E7C for ; Wed, 2 Dec 2020 18:37:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B1574206D5 for ; Wed, 2 Dec 2020 18:37:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729194AbgLBSha (ORCPT ); Wed, 2 Dec 2020 13:37:30 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:35564 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729130AbgLBSha (ORCPT ); Wed, 2 Dec 2020 13:37:30 -0500 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1606934208; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=1foj5CsrViA5SnitgSB9afdnS+nk8RYKri/uQf762Sw=; b=gwasJt4poOMW5wOYjISAkGD39Hg11wWf7RWMwG0ZUzlWUPsB/RtTTOt4qsQx306KjFJi5j 6O17bg2fqul9rX9Hh7jbSJhSyV/gkUEEMRYOpYLGZuuF/zTq4yT6k/n4mF+cg+n78rqByy 4rxxM2Z94IRy1d++35EpyUzWn+adeXAmTdkWZmIKfBZ+8bZFalHYWVkrwtBvxG28/6/kM2 pfNcjf//jQQdKnQcwHodOh9nLEvjQCggxmMEa+Alsu33nNM2p+7pR1JaVPg5sOBFY39XnO tLEK1u+xUzrJYtTj06JUMRMjZFxfjnVZQ69Pi5V8pvGG7m8KoUnAcHn5cTD8mw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1606934208; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=1foj5CsrViA5SnitgSB9afdnS+nk8RYKri/uQf762Sw=; b=RSWTZTk0SHOmL86mzhZi8XFkcjohexnCZi2/sqDGub0NrcrnQm00BCnZQ101U/cSU26Rsy gH8cU2scPQ1K4TAA== To: Miroslav Lichvar Cc: Jason Gunthorpe , linux-kernel@vger.kernel.org, John Stultz , Prarit Bhargava Subject: Re: [PATCH] rtc: adapt allowed RTC update error In-Reply-To: <20201202153656.GC2231584@localhost> References: <20201201143835.2054508-1-mlichvar@redhat.com> <20201201161224.GF5487@ziepe.ca> <20201201171420.GN1900232@localhost> <20201201173540.GH5487@ziepe.ca> <87mtywe2zu.fsf@nanos.tec.linutronix.de> <20201202150725.GA2231584@localhost> <20201202153656.GC2231584@localhost> Date: Wed, 02 Dec 2020 19:36:47 +0100 Message-ID: <87eek8dphc.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 02 2020 at 16:36, Miroslav Lichvar wrote: > On Wed, Dec 02, 2020 at 04:07:28PM +0100, Miroslav Lichvar wrote: >> On Wed, Dec 02, 2020 at 02:44:53PM +0100, Thomas Gleixner wrote: >> > Something like the completely untested below should make this reliable >> > and only needs to retry when the work is running late (busy machine), >> > but the wakeup will be on time or at max 1 jiffie off when high >> > resolution timers are not available or disabled. >> >> It seems to work nicely. In my test most of the updates succeeded on >> the first attempt hitting the right tick, the rest succeeding on the >> second attempt. Only when the clock was set to run 10% faster, it >> needed few more attempts to converge to the target time. > > I noticed an observable change wrt adjtimex() calls though. It seems > it now reschedules the RTC update, i.e. there can be more than one > update per 11 minutes. Was this intended? No. Let me fix that. Thanks, tglx