From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-x82b.google.com (mail-qt1-x82b.google.com [IPv6:2607:f8b0:4864:20::82b]) by sourceware.org (Postfix) with ESMTPS id ED4573851C24 for ; Wed, 24 Mar 2021 21:24:17 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org ED4573851C24 Received: by mail-qt1-x82b.google.com with SMTP id l13so173680qtu.9 for ; Wed, 24 Mar 2021 14:24:17 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=YRNaYG6BnWzuahNMOq4mIbpHav+3BByl4egKNXCKcms=; b=pQRL3BAWAZQ9wBtFXAmk7uIYRcCCCJye9O8RoPl40IvJMdTYoxb58VuXj3IZbB1U9q cdou2rAZYkEjCXzjnfTZSWqVSlMSfUeMHmAf0xeEdFlumNYd9rV/1tIwiP1jTM2JOsVg pzVQvMNuAmauTrQ+xCiCI53Hv+pD6wyVLaU4q4SDhQ6XDWltlWkh3pgjuLsoRwzY7CLk XCpgxPlsiEH3N9O3j12a7oTAXi/QgMAzuPnGloXotRJe8zsVckc0Y+fjPmyF8cHmqXr1 yaODH81EQtr4zYOJdH5qN3F+WqltkyOGQT5KS6IpopDgGq9rMM+firnGZHHox2ZLrcm5 SAwg== X-Gm-Message-State: AOAM530Y9yhzm4Pzxf7I1LvglVAjXh8QcVSWmYudwMC43MVcfUSU2oYu +N5Kl+yLIM5oIPShP96iEAnhRpoLgNVt3w== X-Google-Smtp-Source: ABdhPJzxoA9DIgKt9jBdvBmcZR1BD51MPzaPHym91SD0QBfz+Uaf89+pDRsgiZxIWt57lEu91jcxLQ== X-Received: by 2002:ac8:66d6:: with SMTP id m22mr4897967qtp.56.1616621057417; Wed, 24 Mar 2021 14:24:17 -0700 (PDT) Received: from [192.168.1.132] ([177.194.41.149]) by smtp.gmail.com with ESMTPSA id a20sm2634017qkg.61.2021.03.24.14.24.16 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 24 Mar 2021 14:24:17 -0700 (PDT) Subject: Re: [PATCH] tst: Provide test for select To: "H.J. Lu" Cc: Lukasz Majewski , GNU C Library References: <20210314164625.9312-1-lukma@denx.de> <20210322123213.58775fbd@jawa> <39ac5960-73ef-f838-4409-20384c83b59d@linaro.org> <9dc782d3-c151-1dcb-0a2e-f6397c781761@linaro.org> From: Adhemerval Zanella Message-ID: Date: Wed, 24 Mar 2021 18:24:14 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-12.6 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 24 Mar 2021 21:24:19 -0000 On 24/03/2021 18:21, H.J. Lu wrote: > On Wed, Mar 24, 2021 at 2:14 PM Adhemerval Zanella > wrote: >> >> >> >> On 24/03/2021 17:13, H.J. Lu wrote: >>> On Wed, Mar 24, 2021 at 12:47 PM Adhemerval Zanella >>> wrote: >>>> >>>> >>>> >>>> On 24/03/2021 16:17, H.J. Lu wrote: >>>>> On Mon, Mar 22, 2021 at 4:33 AM Lukasz Majewski wrote: >>>>>> >>>>>> Dear Community, >>>>>> >>>>>>> This change adds new test to assess select()'s timeout related >>>>>>> functionality (the rdfs set provides valid fd - stderr - but during >>>>>>> normal program operation there is no data to be read, so one just >>>>>>> waits for timeout). >>>>>>> >>>>>>> To be more specific - two use cases are checked: >>>>>>> - if select() times out immediately when passed struct timeval has >>>>>>> zero values of tv_usec and tv_sec. >>>>>>> - if select() times out after timeout specified in passed argument >>>>>> >>>>>> Do you have any comments regarding this patch? >>>>>> >>>>> >>>>> This test failed on machines with more than 40 cores: >>>>> >>>>> tst-select.c:54: 1616610088.851713938s not after 1616610089.851712804s >>>>> (difference 0.999998866s) >>>>> error: 1 test failures >>>>> >>>>> I was doing 3 "makec -j28 check" in parallel. >>>> >>>> I think the nanosecond precision of time accounting is triggering the >>>> failure, since select only support timeval (the error indicates that >>>> the nanosecond precision is what is triggering it). >>>> >>>> Maybe if we ignore the nanosecond precision: >>>> >>>> diff --git a/misc/tst-select.c b/misc/tst-select.c >>>> index 7c310256c5..4b1791ac8a 100644 >>>> --- a/misc/tst-select.c >>>> +++ b/misc/tst-select.c >>>> @@ -45,6 +45,8 @@ test_select_timeout (bool zero_tmo) >>>> to.tv_sec = timeout; >>>> ts = xclock_now (CLOCK_REALTIME); >>>> ts = timespec_add (ts, (struct timespec) { timeout, 0 }); >>>> + /* Ignore nanosecond precision since select only support microsecond. */ >>>> + ts.tv_nsec = (ts.tv_nsec * 1000) / 1000; >>> >>> How does it work? It looks like a NOP to me. >> >> The idea is to clear the nanosecond precision from the xclock_now call. > > I tried it. It doesn't solve the problem. I opened: > > https://sourceware.org/bugzilla/show_bug.cgi?id=27648 I think we will need to clear out on the TEST_TIMESPEC_NOW_OR_AFTER as well (by adding another macro).