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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 4C2B9CA9EA0 for ; Wed, 23 Oct 2019 01:51:28 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 1A87620679 for ; Wed, 23 Oct 2019 01:51:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A87620679 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50854 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iN5o7-0007VM-95 for qemu-devel@archiver.kernel.org; Tue, 22 Oct 2019 21:51:27 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43813) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iN5nV-00074J-QM for qemu-devel@nongnu.org; Tue, 22 Oct 2019 21:50:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iN5nU-0003mX-PP for qemu-devel@nongnu.org; Tue, 22 Oct 2019 21:50:49 -0400 Received: from mga18.intel.com ([134.134.136.126]:5647) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iN5nU-0003mI-I6 for qemu-devel@nongnu.org; Tue, 22 Oct 2019 21:50:48 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Oct 2019 18:50:47 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,218,1569308400"; d="scan'208";a="188098250" Received: from txu2-mobl.ccr.corp.intel.com (HELO [10.239.197.6]) ([10.239.197.6]) by orsmga007.jf.intel.com with ESMTP; 22 Oct 2019 18:50:45 -0700 Subject: Re: [PATCH v13 01/12] util/cutils: Add qemu_strtotime_ps() To: Eric Blake References: <20191020111125.27659-1-tao3.xu@intel.com> <20191020111125.27659-2-tao3.xu@intel.com> <7a0662f5-28e3-4bb8-0b20-669d34cf56a6@redhat.com> From: Tao Xu Message-ID: Date: Wed, 23 Oct 2019 09:50:44 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <7a0662f5-28e3-4bb8-0b20-669d34cf56a6@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.126 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "ehabkost@redhat.com" , "Liu, Jingqi" , "Du, Fan" , "qemu-devel@nongnu.org" , "jonathan.cameron@huawei.com" , "imammedo@redhat.com" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 10/23/2019 9:13 AM, Eric Blake wrote: > On 10/20/19 6:11 AM, Tao Xu wrote: >> To convert strings with time suffixes to numbers, support time unit are >> "ps" for picosecond, "ns" for nanosecond, "us" for microsecond, "ms" >> for millisecond or "s" for second. > > I haven't yet reviewed the patch itself, but my off-hand observation: > > picosecond is probably too narrow to ever be useful. POSIX interfaces > only go down to nanoseconds, and when you start adding in vmexit delay > times and such, we're lucky when we get anything better than microsecond > accuracies. Supporting just three sub-second suffixes instead of four > would slightly simplify the code, and not cost you any real precision. > Thank you for your suggestion.