From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk1-x732.google.com (mail-qk1-x732.google.com [IPv6:2607:f8b0:4864:20::732]) by sourceware.org (Postfix) with ESMTPS id 99E0A3851C24 for ; Wed, 24 Mar 2021 21:14:46 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 99E0A3851C24 Received: by mail-qk1-x732.google.com with SMTP id v70so19596566qkb.8 for ; Wed, 24 Mar 2021 14:14:46 -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=82rqd9X1u+E/yxNAPCBqFaotmxw6JwzWFpdpXhhEFHo=; b=P41AJsijNDUPcGM9MkRRxuM1kjhgbBY/0QjkdedfWsFyoxD/m2f1NAnEBbzjKxEo6y 3dZKkt8v15Ceb+8WIVBHEHaximmTwtIkz/nt0LMubLQD3CHE0Ozt65nfgsp3tNefsusP KOhSllXCReExGR+iKI2xwRlhV11gecJG/bkXGWYe/1KtMF6K8zOB+U9+TMt4fCypBm/m KHm8a7NQ2P6+qGKCgVcnssi75jUD5WqGn3lArWZ71F1+AtwIwYTkatLFnrjR7utxhguZ a6KUsG6kSuwjecfMFkv3xugIWxla8cA05Z4OVFXY4N5j4wv5Q0zRFEcC4VFcakXMBV8y XrDg== X-Gm-Message-State: AOAM533ZsyBMdXMM3O4B2NEw25XkH/nkfTv4Tv8YjQTF6ZPZBGprJhQJ X4ttMzk6u1SIHSfif90jRiJi1TXRc7vamw== X-Google-Smtp-Source: ABdhPJwCv+jKJDSLH2YYo+1JKINaGWoQXmMZuUiO9xaS4uOATmjiWxHL5mQBbW44ougfIa/qi4P0/w== X-Received: by 2002:a05:620a:1410:: with SMTP id d16mr5107010qkj.465.1616620486012; Wed, 24 Mar 2021 14:14:46 -0700 (PDT) Received: from [192.168.1.132] ([177.194.41.149]) by smtp.gmail.com with ESMTPSA id u63sm2312118qtd.40.2021.03.24.14.14.44 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 24 Mar 2021 14:14:45 -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> From: Adhemerval Zanella Message-ID: <9dc782d3-c151-1dcb-0a2e-f6397c781761@linaro.org> Date: Wed, 24 Mar 2021 18:14:43 -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=-12.5 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 21:14:47 -0000 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.