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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 31180C433ED for ; Sun, 2 May 2021 14:55:07 +0000 (UTC) Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AE3B3600D1 for ; Sun, 2 May 2021 14:55:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AE3B3600D1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kroah.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernelnewbies-bounces@kernelnewbies.org Received: from localhost ([::1] helo=shelob.surriel.com) by shelob.surriel.com with esmtp (Exim 4.94) (envelope-from ) id 1ldDUk-000351-7K; Sun, 02 May 2021 10:54:54 -0400 Received: from out2-smtp.messagingengine.com ([66.111.4.26]) by shelob.surriel.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1ldDUh-00034T-FY for kernelnewbies@kernelnewbies.org; Sun, 02 May 2021 10:54:51 -0400 Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id 4718C5C013A; Sun, 2 May 2021 10:54:48 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute1.internal (MEProxy); Sun, 02 May 2021 10:54:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kroah.com; h= date:from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm3; bh=B/m8SaZghjFAM166HnGPAE0xAYA atlB6wcWusyZK8Cw=; b=GQ3JINBtf+PFVnR2P7CHaZQoW4PmNLlp0UIL3iUNGbY rIbCgk0G52dEO2OywLGYmKrRpasWDivCrmDuBBnhWqNaGJFJnd92laK6h4kDOoRX lJQpmh+4yhRHC/x02+EKDAjIzZsx0huicaxrPFvQB7ct+iHyCBNWiYavN/rrbToR EdhlPJDyxvaQA/owQESuDe5X/bmaIuL9tMmX/2I6ifiDTKNginnoBT2spDw2SikC FxcsBMN56CXf8A9itFBsNznvc6vTUtUFcxldxsyVN1vgmTxpcGZLntOg/TpwOc4E v3Hm6YT84x9Q3IaI+3taf2rOK1bmfBLABcrMj0AYtEQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=B/m8Sa ZghjFAM166HnGPAE0xAYAatlB6wcWusyZK8Cw=; b=Gq+KW/GaVvysVlvc/mWCgD mIYW/So52byg4e20jhyBboC5/aPu6ILyoBCSvoLnilBdvQNyh+ZqIdAVGGF6ADdm 58Fv31DvtZMNnGL3Hx/cd+zViwNu7PEidO7BdJ/W2gu3NbznDUqPIAb/2ZVaKktR q2k+3swVCN8wEIWmPHsoU8kgeGIiDR7/4rSC5VfGNLJ5K6rmZNF4tlUz2CVg5cQJ tAE2X9/3CZtj0WXT6/ri2Xnv0R7Ry7n6Uxo6bf3xXQ+MgIQRE/OF+mNXM7mZp8GZ P1TtQLQaVr9lijINygJzHo1s8DiM6H2YWOKFexOq+ksTxxqBBfdhDHGXrFL1VNZA == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrvdefuddgudeffecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecunecujfgurhepfffhvffukfhfgggtuggjsehttd ertddttddvnecuhfhrohhmpefirhgvghcumffjuceoghhrvghgsehkrhhorghhrdgtohhm qeenucggtffrrghtthgvrhhnpeevueehjefgfffgiedvudekvdektdelleelgefhleejie eugeegveeuuddukedvteenucfkphepkeefrdekiedrjeegrdeigeenucevlhhushhtvghr ufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehgrhgvgheskhhrohgrhhdrtg homh X-ME-Proxy: Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) by mail.messagingengine.com (Postfix) with ESMTPA; Sun, 2 May 2021 10:54:47 -0400 (EDT) Date: Sun, 2 May 2021 16:54:45 +0200 From: Greg KH To: Hyeonggon Yoo <42.hyeyoo@gmail.com> Subject: Re: high precision timers Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Cc: kernelnewbies@kernelnewbies.org X-BeenThere: kernelnewbies@kernelnewbies.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Learn about the Linux kernel List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kernelnewbies-bounces@kernelnewbies.org On Sun, May 02, 2021 at 11:10:11PM +0900, Hyeonggon Yoo wrote: > the 'timer wheel' - which has low resolution works at jiffy resolution. > so usually it has precision of 1~10ms. > > and there's high resolution timers in kernel to have nanosecond resolution, > but it doesn't seem to have nanosecond precision > > is there a way to deal with high precision timers in kernel? What exactly are you needing here? And do you have hardware that provides both high precision and high resolution? thanks, greg k-h _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies