From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Fri, 04 Nov 2022 09:55:57 +0100 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1oqsUX-00Ejwj-P7 for lore@lore.pengutronix.de; Fri, 04 Nov 2022 09:55:57 +0100 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1oqsUW-0006ZW-Ml for lore@pengutronix.de; Fri, 04 Nov 2022 09:55:57 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:From:In-Reply-To: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=991sD/UaIk5cQtgb6pejmqgahvg2pvKv+fVEi+RIp1A=; b=Hj8nUJtYdwFN6NtAL/GWuGTNDT 91+Oo15redghkmIIh132aWWD4RCjS/SVbTE02hbcPHNwixlrX2Y5NiotfKFRsUVhieUL/kz59PbKA Hlf2PmUmVbHLY7e8V9Xnw6NTER/TjwIAKAfwEM5I1OSVc732zxz4HRcaoLH23wM+jIfAwGoxEVkLf f857vYdQ2L0eGgQzFYf2s3wQl5C5rJTwMsZIdFzFDoFBHUwa5nPuhQtk+FR0bkRa1zuIi1FGuxL/3 MJc0cvLJd9mTZqCnD4FO1iXVRS6t5N1Z8RsoSDSCdbkjFgF4YwLjRpaWOs0Fq7kuFl9u18u6V6M2h dg5evTbw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oqsTJ-00318j-Q7; Fri, 04 Nov 2022 08:54:41 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oqsTE-00317P-IG for barebox@lists.infradead.org; Fri, 04 Nov 2022 08:54:38 +0000 Received: from ptx.hi.pengutronix.de ([2001:67c:670:100:1d::c0]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1oqsTD-0006Ac-7U; Fri, 04 Nov 2022 09:54:35 +0100 Received: from sha by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1oqsTD-0006Yp-0F; Fri, 04 Nov 2022 09:54:35 +0100 Date: Fri, 4 Nov 2022 09:54:34 +0100 To: Ahmad Fatoum Cc: barebox@lists.infradead.org Message-ID: <20221104085434.GV3143@pengutronix.de> References: <20221102085017.1941580-1-a.fatoum@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221102085017.1941580-1-a.fatoum@pengutronix.de> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-Accept-Language: de,en X-Accept-Content-Type: text/plain User-Agent: Mutt/1.10.1 (2018-07-13) From: Sascha Hauer X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221104_015436_618674_6DDFA0FB X-CRM114-Status: GOOD ( 21.84 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.ext.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.2 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH] commands: uptime: add note about caveats X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.ext.pengutronix.de) On Wed, Nov 02, 2022 at 09:50:17AM +0100, Ahmad Fatoum wrote: > Normally timer overrun is not that much of a problem, because there > where it matters, we usually have an is_timeout() in the loop that reads > the timer often enough. This doesn't necessarily hold for the new uptime > command and basically anything can happen between subsequent calls and > if get_time_ns() is not called often enough during that time, we end up > with an inaccurate uptime. Mention this in the extended help text. > > Signed-off-by: Ahmad Fatoum > --- > Can be squashed into original commit. > --- > commands/uptime.c | 3 +++ > 1 file changed, 3 insertions(+) Applied, thanks Sascha > > diff --git a/commands/uptime.c b/commands/uptime.c > index a9a8c650b698..d67538631c8f 100644 > --- a/commands/uptime.c > +++ b/commands/uptime.c > @@ -66,6 +66,9 @@ static int do_uptime(int argc, char *argv[]) > BAREBOX_CMD_HELP_START(uptime) > BAREBOX_CMD_HELP_TEXT("This command formats the number of elapsed nanoseconds") > BAREBOX_CMD_HELP_TEXT("as measured with the current clocksource") > +BAREBOX_CMD_HELP_TEXT("Note: Timekeeping is co-operative. If long running code does") > +BAREBOX_CMD_HELP_TEXT("not use delay/is_timeout/get_time_ns/getchar functions") > +BAREBOX_CMD_HELP_TEXT("timer may overrun resulting in incorrect results") > BAREBOX_CMD_HELP_TEXT("Options:") > BAREBOX_CMD_HELP_OPT ("-n", "output elapsed time in nanoseconds") > BAREBOX_CMD_HELP_END > -- > 2.30.2 > > > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |