From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by sourceware.org (Postfix) with ESMTPS id 1263D3940CE1 for ; Tue, 17 Mar 2020 14:53:47 +0000 (GMT) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id B92F9AE17; Tue, 17 Mar 2020 14:53:45 +0000 (UTC) Subject: Re: [PATCH][gdb/testsuite] Give up after consecutive timeouts in completion-support.exp To: Simon Marchi , gdb-patches@sourceware.org References: <20200316175925.GA5989@delia> From: Tom de Vries Autocrypt: addr=tdevries@suse.de; keydata= xsBNBF0ltCcBCADDhsUnMMdEXiHFfqJdXeRvgqSEUxLCy/pHek88ALuFnPTICTwkf4g7uSR7 HvOFUoUyu8oP5mNb4VZHy3Xy8KRZGaQuaOHNhZAT1xaVo6kxjswUi3vYgGJhFMiLuIHdApoc u5f7UbV+egYVxmkvVLSqsVD4pUgHeSoAcIlm3blZ1sDKviJCwaHxDQkVmSsGXImaAU+ViJ5l CwkvyiiIifWD2SoOuFexZyZ7RUddLosgsO0npVUYbl6dEMq2a5ijGF6/rBs1m3nAoIgpXk6P TCKlSWVW6OCneTaKM5C387972qREtiArTakRQIpvDJuiR2soGfdeJ6igGA1FZjU+IsM5ABEB AAHNH1RvbSBkZSBWcmllcyA8dGRldnJpZXNAc3VzZS5kZT7CwKsEEwEIAD4WIQSsnSe5hKbL MK1mGmjuhV2rbOJEoAUCXSW0JwIbAwUJA8JnAAULCQgHAgYVCgkICwIEFgIDAQIeAQIXgAAh CRDuhV2rbOJEoBYhBKydJ7mEpsswrWYaaO6FXats4kSgc48H/Ra2lq5p3dHsrlQLqM7N68Fo eRDf3PMevXyMlrCYDGLVncQwMw3O/AkousktXKQ42DPJh65zoXB22yUt8m0g12xkLax98KFJ 5NyUloa6HflLl+wQL/uZjIdNUQaHQLw3HKwRMVi4l0/Jh/TygYG1Dtm8I4o708JS4y8GQxoQ UL0z1OM9hyM3gI2WVTTyprsBHy2EjMOu/2Xpod95pF8f90zBLajy6qXEnxlcsqreMaqmkzKn 3KTZpWRxNAS/IH3FbGQ+3RpWkNGSJpwfEMVCeyK5a1n7yt1podd1ajY5mA1jcaUmGppqx827 8TqyteNe1B/pbiUt2L/WhnTgW1NC1QDOwE0EXSW0JwEIAM99H34Bu4MKM7HDJVt864MXbx7B 1M93wVlpJ7Uq+XDFD0A0hIal028j+h6jA6bhzWto4RUfDl/9mn1StngNVFovvwtfzbamp6+W pKHZm9X5YvlIwCx131kTxCNDcF+/adRW4n8CU3pZWYmNVqhMUiPLxElA6QhXTtVBh1RkjCZQ Kmbd1szvcOfaD8s+tJABJzNZsmO2hVuFwkDrRN8Jgrh92a+yHQPd9+RybW2l7sJv26nkUH5Z 5s84P6894ebgimcprJdAkjJTgprl1nhgvptU5M9Uv85Pferoh2groQEAtRPlCGrZ2/2qVNe9 XJfSYbiyedvApWcJs5DOByTaKkcAEQEAAcLAkwQYAQgAJhYhBKydJ7mEpsswrWYaaO6FXats 4kSgBQJdJbQnAhsMBQkDwmcAACEJEO6FXats4kSgFiEErJ0nuYSmyzCtZhpo7oVdq2ziRKD3 twf7BAQBZ8TqR812zKAD7biOnWIJ0McV72PFBxmLIHp24UVe0ZogtYMxSWKLg3csh0yLVwc7 H3vldzJ9AoK3Qxp0Q6K/rDOeUy3HMqewQGcqrsRRh0NXDIQk5CgSrZslPe47qIbe3O7ik/MC q31FNIAQJPmKXX25B115MMzkSKlv4udfx7KdyxHrTSkwWZArLQiEZj5KG4cCKhIoMygPTA3U yGaIvI/BGOtHZ7bEBVUCFDFfOWJ26IOCoPnSVUvKPEOH9dv+sNy7jyBsP5QxeTqwxC/1ZtNS DUCSFQjqA6bEGwM22dP8OUY6SC94x1G81A9/xbtm9LQxKm0EiDH8KBMLfQ== Message-ID: <5ffff0ef-e2f6-82ea-306c-a661e9ae830c@suse.de> Date: Tue, 17 Mar 2020 15:53:44 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 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=0.0 required=5.0 tests=KAM_DMARC_STATUS, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS 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: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Mar 2020 14:53:48 -0000 On 17-03-2020 15:30, Simon Marchi wrote: > On 2020-03-16 1:59 p.m., Tom de Vries wrote: >> Hi, >> >> When running test-case gdb.linespec/cpcompletion.exp with target board >> unix/-flto/-O0/-flto-partition=none/-ffat-lto-objects, we run into lots of >> timeouts, in particular with this pattern: >> ... >> FAIL: gdb.linespec/cpcompletion.exp: template-ret-type: \ >> cmd complete "b template2_" >> FAIL: gdb.linespec/cpcompletion.exp: template-ret-type: \ >> tab complete "b template2_st" (timeout) >> FAIL: gdb.linespec/cpcompletion.exp: template-ret-type: \ >> cmd complete "b template2_st" >> FAIL: gdb.linespec/cpcompletion.exp: template-ret-type: \ >> tab complete "b template2_str" (timeout) >> FAIL: gdb.linespec/cpcompletion.exp: template-ret-type: \ >> cmd complete "b template2_str" >> FAIL: gdb.linespec/cpcompletion.exp: template-ret-type: \ >> tab complete "b template2_stru" (timeout) >> ... >> >> Fix this by detecting timeouts in test_complete_prefix_range_re and giving up >> after 3 consecutive timeouts. >> >> This reduces testing time from ~39m to ~9m. >> >> Tested on x86_64-linux. >> >> OK for trunk? >> >> Thanks, >> - Tom > > Hi Tom, > > My only question is: why retry when we get a timeout? > > If we get a timeout because GDB takes time to respond, then shouldn't the timeout > time be increased? > > If we get a timeout because GDB doesn't respond the right thing, then shouldn't > we return immediately to avoid further timeouts, given the test has already failed? > Well, here's how I reasoned. Say for a string "abcdefgh" we test "a", "ab", "abc", etc. If we timeout at "a", there is the change that it's f.i. specific to one-letter matches, and such timeouts will not occur of "ab" and so on. So, we try to establish a pattern: if "a", "ab" and "abc" timeout, then we think there's a good chance that "abcd" will also timeout, and we give up. Having said that, my reasoning above is more concerned with not testing too little. Your reasoning is more concerned with having less timeouts. So I think both approaches are valid, they're just different trade-off points. I'm fine with submitting a follow up patch that gives up after the first timeout, if you prefer that. Thanks, - Tom