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[80.11.63.14]) by smtp.gmail.com with ESMTPSA id b194sm1447071wmg.46.2019.09.23.23.44.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 23 Sep 2019 23:44:32 -0700 (PDT) To: Peter Zijlstra Cc: Jens Axboe , Ingo Molnar , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190923071932.GD2349@hirez.programming.kicks-ass.net> <3e359937-5b19-8a4c-4243-ba2edff68504@gmail.com> <20190923192742.GH2369@hirez.programming.kicks-ass.net> From: Pavel Begunkov Autocrypt: addr=asml.silence@gmail.com; prefer-encrypt=mutual; keydata= mQINBFmKBOQBEAC76ZFxLAKpDw0bKQ8CEiYJRGn8MHTUhURL02/7n1t0HkKQx2K1fCXClbps bdwSHrhOWdW61pmfMbDYbTj6ZvGRvhoLWfGkzujB2wjNcbNTXIoOzJEGISHaPf6E2IQx1ik9 6uqVkK1OMb7qRvKH0i7HYP4WJzYbEWVyLiAxUj611mC9tgd73oqZ2pLYzGTqF2j6a/obaqha +hXuWTvpDQXqcOZJXIW43atprH03G1tQs7VwR21Q1eq6Yvy2ESLdc38EqCszBfQRMmKy+cfp W3U9Mb1w0L680pXrONcnlDBCN7/sghGeMHjGKfNANjPc+0hzz3rApPxpoE7HC1uRiwC4et83 CKnncH1l7zgeBT9Oa3qEiBlaa1ZCBqrA4dY+z5fWJYjMpwI1SNp37RtF8fKXbKQg+JuUjAa9 Y6oXeyEvDHMyJYMcinl6xCqCBAXPHnHmawkMMgjr3BBRzODmMr+CPVvnYe7BFYfoajzqzq+h EyXSl3aBf0IDPTqSUrhbmjj5OEOYgRW5p+mdYtY1cXeK8copmd+fd/eTkghok5li58AojCba jRjp7zVOLOjDlpxxiKhuFmpV4yWNh5JJaTbwCRSd04sCcDNlJj+TehTr+o1QiORzc2t+N5iJ NbILft19Izdn8U39T5oWiynqa1qCLgbuFtnYx1HlUq/HvAm+kwARAQABtDFQYXZlbCBCZWd1 bmtvdiAoc2lsZW5jZSkgPGFzbWwuc2lsZW5jZUBnbWFpbC5jb20+iQJOBBMBCAA4FiEE+6Ju PTjTbx479o3OWt5b1Glr+6UFAlmKBOQCGwMFCwkIBwIGFQgJCgsCBBYCAwECHgECF4AACgkQ Wt5b1Glr+6WxZA//QueaKHzgdnOikJ7NA/Vq8FmhRlwgtP0+E+w93kL+ZGLzS/cUCIjn2f4Q Mcutj2Neg0CcYPX3b2nJiKr5Vn0rjJ/suiaOa1h1KzyNTOmxnsqE5fmxOf6C6x+NKE18I5Jy xzLQoktbdDVA7JfB1itt6iWSNoOTVcvFyvfe5ggy6FSCcP+m1RlR58XxVLH+qlAvxxOeEr/e aQfUzrs7gqdSd9zQGEZo0jtuBiB7k98t9y0oC9Jz0PJdvaj1NZUgtXG9pEtww3LdeXP/TkFl HBSxVflzeoFaj4UAuy8+uve7ya/ECNCc8kk0VYaEjoVrzJcYdKP583iRhOLlZA6HEmn/+Gh9 4orG67HNiJlbFiW3whxGizWsrtFNLsSP1YrEReYk9j1SoUHHzsu+ZtNfKuHIhK0sU07G1OPN 2rDLlzUWR9Jc22INAkhVHOogOcc5ajMGhgWcBJMLCoi219HlX69LIDu3Y34uIg9QPZIC2jwr 24W0kxmK6avJr7+n4o8m6sOJvhlumSp5TSNhRiKvAHB1I2JB8Q1yZCIPzx+w1ALxuoWiCdwV M/azguU42R17IuBzK0S3hPjXpEi2sK/k4pEPnHVUv9Cu09HCNnd6BRfFGjo8M9kZvw360gC1 reeMdqGjwQ68o9x0R7NBRrtUOh48TDLXCANAg97wjPoy37dQE7e5Ag0EWYoE5AEQAMWS+aBV IJtCjwtfCOV98NamFpDEjBMrCAfLm7wZlmXy5I6o7nzzCxEw06P2rhzp1hIqkaab1kHySU7g dkpjmQ7Jjlrf6KdMP87mC/Hx4+zgVCkTQCKkIxNE76Ff3O9uTvkWCspSh9J0qPYyCaVta2D1 Sq5HZ8WFcap71iVO1f2/FEHKJNz/YTSOS/W7dxJdXl2eoj3gYX2UZNfoaVv8OXKaWslZlgqN jSg9wsTv1K73AnQKt4fFhscN9YFxhtgD/SQuOldE5Ws4UlJoaFX/yCoJL3ky2kC0WFngzwRF Yo6u/KON/o28yyP+alYRMBrN0Dm60FuVSIFafSqXoJTIjSZ6olbEoT0u17Rag8BxnxryMrgR dkccq272MaSS0eOC9K2rtvxzddohRFPcy/8bkX+t2iukTDz75KSTKO+chce62Xxdg62dpkZX xK+HeDCZ7gRNZvAbDETr6XI63hPKi891GeZqvqQVYR8e+V2725w+H1iv3THiB1tx4L2bXZDI DtMKQ5D2RvCHNdPNcZeldEoJwKoA60yg6tuUquvsLvfCwtrmVI2rL2djYxRfGNmFMrUDN1Xq F3xozA91q3iZd9OYi9G+M/OA01husBdcIzj1hu0aL+MGg4Gqk6XwjoSxVd4YT41kTU7Kk+/I 5/Nf+i88ULt6HanBYcY/+Daeo/XFABEBAAGJAjYEGAEIACAWIQT7om49ONNvHjv2jc5a3lvU aWv7pQUCWYoE5AIbDAAKCRBa3lvUaWv7pfmcEACKTRQ28b1y5ztKuLdLr79+T+LwZKHjX++P 4wKjEOECCcB6KCv3hP+J2GCXDOPZvdg/ZYZafqP68Yy8AZqkfa4qPYHmIdpODtRzZSL48kM8 LRzV8Rl7J3ItvzdBRxf4T/Zseu5U6ELiQdCUkPGsJcPIJkgPjO2ROG/ZtYa9DvnShNWPlp+R uPwPccEQPWO/NP4fJl2zwC6byjljZhW5kxYswGMLBwb5cDUZAisIukyAa8Xshdan6C2RZcNs rB3L7vsg/R8UCehxOH0C+NypG2GqjVejNZsc7bgV49EOVltS+GmGyY+moIzxsuLmT93rqyII 5rSbbcTLe6KBYcs24XEoo49Zm9oDA3jYvNpeYD8rDcnNbuZh9kTgBwFN41JHOPv0W2FEEWqe JsCwQdcOQ56rtezdCJUYmRAt3BsfjN3Jn3N6rpodi4Dkdli8HylM5iq4ooeb5VkQ7UZxbCWt UVMKkOCdFhutRmYp0mbv2e87IK4erwNHQRkHUkzbsuym8RVpAZbLzLPIYK/J3RTErL6Z99N2 m3J6pjwSJY/zNwuFPs9zGEnRO4g0BUbwGdbuvDzaq6/3OJLKohr5eLXNU3JkT+3HezydWm3W OPhauth7W0db74Qd49HXK0xe/aPrK+Cp+kU1HRactyNtF8jZQbhMCC8vMGukZtWaAwpjWiiH bA== Subject: Re: [PATCH v2 1/2] sched/wait: Add wait_threshold Message-ID: <8c83b046-5c8a-7303-5541-180c094c875e@gmail.com> Date: Tue, 24 Sep 2019 09:44:22 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.0 MIME-Version: 1.0 In-Reply-To: <20190923192742.GH2369@hirez.programming.kicks-ass.net> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="wUDcp9ReHPFbKHIMBDPwE48ahAdhUiuKN" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --wUDcp9ReHPFbKHIMBDPwE48ahAdhUiuKN Content-Type: multipart/mixed; boundary="dbvsh10GjxbNpjdrbHkJFIaxLPkiCmEBz"; protected-headers="v1" From: Pavel Begunkov To: Peter Zijlstra Cc: Jens Axboe , Ingo Molnar , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Message-ID: <8c83b046-5c8a-7303-5541-180c094c875e@gmail.com> Subject: Re: [PATCH v2 1/2] sched/wait: Add wait_threshold References: <20190923071932.GD2349@hirez.programming.kicks-ass.net> <3e359937-5b19-8a4c-4243-ba2edff68504@gmail.com> <20190923192742.GH2369@hirez.programming.kicks-ass.net> In-Reply-To: <20190923192742.GH2369@hirez.programming.kicks-ass.net> --dbvsh10GjxbNpjdrbHkJFIaxLPkiCmEBz Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 23/09/2019 22:27, Peter Zijlstra wrote: >=20 > A: Because it messes up the order in which people normally read text. > Q: Why is top-posting such a bad thing? > A: Top-posting. > Q: What is the most annoying thing in e-mail? >=20 > On Mon, Sep 23, 2019 at 07:37:46PM +0300, Pavel Begunkov wrote: >> Just in case duplicating a mail from the cover-letter thread: >=20 > Just because every patch should have a self contained and coherent > Changelog. Well, I will expand the patch description, if we agree on the implementation (at least conceptually). >> >> BTW, this monster is mostly a copy-paste from wait_event_*(), >> wait_bit_*(). We could try to extract some common parts from these >> three, but that's another topic. >=20 > I don't think that is another topic at all. It is a quality of > implementation issue. We already have too many copies of all that (3). For example, ___wait_event() is copied in ___wait_var_event(). Instead it could accept a wait entry generator or just accept entry from above and be reused in both cases. I've had such a patch, but want to think what else could be done. e.g. ``` #define generic_wait_event(ENTRY_GEN, ...) ENTRY_GEN(wq_entry_name); do_wait_event(wq_entry_name); #define WBQ_ENTRY_GEN(name) struct wait_bit_queue_entry tmp =3D WBQ_INITIALIZER; struct wait_queue_entry name =3D &tmp->wq_entry; ``` >=20 > So basically you want to fudge the wake function to do the/a @cond test= , > not unlike what wait_bit already does, but differenly. >=20 Yes > I'm really rather annoyed with C for not having proper lambda functions= ; > that would make all this so much easier. Anyway, let me have a poke at > this in the morning, it's late already. >=20 > Also, is anything actually using wait_queue_entry::private ? I'm > not finding any in a hurry. >=20 >=20 --=20 Yours sincerely, Pavel Begunkov --dbvsh10GjxbNpjdrbHkJFIaxLPkiCmEBz-- --wUDcp9ReHPFbKHIMBDPwE48ahAdhUiuKN Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEE+6JuPTjTbx479o3OWt5b1Glr+6UFAl2Ju0oACgkQWt5b1Glr +6V7jhAAjffsfaXaHfWydGfYxTJ/0b1pXmjU2TDl9MHNSBYT8k5bMWHhCl95BfkZ bVKqg+3avqjVoBou3Vz44C/xd7OuleSnXfz+5NXWrBV4twTwOpQPqWGPgblHh3iW 6PEgAXjjP1/D2FoSSVUobw3cC2UUDhNh3R+vLES6PZOS0ktxqIway4T8sWJciPYM K4x48t7O+Teg5LQDXBfLqmCoNb5tRdaBDyzvLOi5B7QQei/Uw72K77pMs8QJCWnb dd5Dxz5J7ZZY9Q+d1rN4gT2uKhnFj51eueHrN/j/ffVk3s8FR0yESoTXqvPslcto DqMtrxUD0z2ssiN4DkiV121w8biCnbBfqbgqI6j+DHkQhCrliRplmyJPDayzlRu2 z/w222jNJSq7JyH+Ezpitk37fVnv8QLmeGW49Yx5VKVxZU+ER6SFbp+ZzImWExWC H5gmD8tGuHv4gBCjq4FDBEg0tEfhnPF5CWp/1hGoWP0zwEHWku4ea74OUh0m3Ocq VfGBkdqE9XKVMNRMQhbtwEAiDazItREUw/SFLnHivpqSXTmyzj08i5Jk+47pkTbF +necWNB37dVmmPZYIlmFRX8Ce/bXxSRDiEyuPgiZq4XqEjRkOpu6eLXZ1pRBsPsL JZo4uh2rmjdj/H5RbkWfGuJx1Yy+QcZ1r3bDtpuS6+IZJrnIwFs= =BN0u -----END PGP SIGNATURE----- --wUDcp9ReHPFbKHIMBDPwE48ahAdhUiuKN--