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Sat, 21 Dec 2019 09:27:05 -0800 (PST) Received: from [192.168.43.10] ([109.126.149.134]) by smtp.gmail.com with ESMTPSA id f1sm14241567wro.85.2019.12.21.09.27.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 21 Dec 2019 09:27:05 -0800 (PST) To: Jens Axboe , io-uring@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Tejun Heo , Dennis Zhou , Christoph Lameter References: <925d8fe5406779bbfa108caa3d1f9fd16e3434b5.1576944502.git.asml.silence@gmail.com> 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 RFC v2 3/3] io_uring: batch get(ctx->ref) across submits Message-ID: Date: Sat, 21 Dec 2019 20:26:22 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="AzNQoLv2McupmGhnzJNm9urb2gLHcd6HN" Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --AzNQoLv2McupmGhnzJNm9urb2gLHcd6HN Content-Type: multipart/mixed; boundary="3uFrkmDlTApU8qTA9VHwffF0MAgdcG3lG"; protected-headers="v1" From: Pavel Begunkov To: Jens Axboe , io-uring@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Tejun Heo , Dennis Zhou , Christoph Lameter Message-ID: Subject: Re: [PATCH RFC v2 3/3] io_uring: batch get(ctx->ref) across submits References: <925d8fe5406779bbfa108caa3d1f9fd16e3434b5.1576944502.git.asml.silence@gmail.com> In-Reply-To: --3uFrkmDlTApU8qTA9VHwffF0MAgdcG3lG Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 21/12/2019 20:01, Jens Axboe wrote: > On 12/21/19 9:48 AM, Pavel Begunkov wrote: >> On 21/12/2019 19:38, Jens Axboe wrote: >>> On 12/21/19 9:20 AM, Pavel Begunkov wrote: >>>> On 21/12/2019 19:15, Pavel Begunkov wrote: >>>>> Double account ctx->refs keeping number of taken refs in ctx. As >>>>> io_uring gets per-request ctx->refs during submission, while holdin= g >>>>> ctx->uring_lock, this allows in most of the time to bypass >>>>> percpu_ref_get*() and its overhead. >>>> >>>> Jens, could you please benchmark with this one? Especially for offlo= aded QD1 >>>> case. I haven't got any difference for nops test and don't have a de= cent SSD >>>> at hands to test it myself. We could drop it, if there is no benefit= =2E >>>> >>>> This rewrites that @extra_refs from the second one, so I left it for= now. >>> >>> Sure, let me run a peak test, qd1 test, qd1+sqpoll test on >>> for-5.6/io_uring, same branch with 1-2, and same branch with 1-3. Tha= t >>> should give us a good comparison. One core used for all, and we're go= ing >>> to be core speed bound for the performance in all cases on this setup= =2E >>> So it'll be a good comparison. >>> >> Great, thanks! >=20 > For some reason, not seeing much of a change between for-5.6/io_uring > and 1+2 and 1+2+3, it's about the same and results seem very stable. > For reference, top of profile with 1-3 applied looks like this: I see. I'll probably drop the last one, as it only complicates things. My apologies for misleading terminology. Read-only QD1 (submit and wait until the userspace completes it) obviously won't saturate a CPU. Writes probably wouldn't as well (though, depends on HW). And it would be= better to say -- submit by one, complete in a bunch. Just curious, what you used for testing? Is it fio? >=20 > + 3.92% io_uring [kernel.vmlinux] [k] blkdev_direct_IO > + 3.87% io_uring [kernel.vmlinux] [k] blk_mq_get_request > + 3.43% io_uring [kernel.vmlinux] [k] io_iopoll_getevents > + 3.03% io_uring [kernel.vmlinux] [k] __slab_free > + 2.87% io_uring io_uring [.] submitter_fn > + 2.79% io_uring [kernel.vmlinux] [k] io_submit_sqes > + 2.75% io_uring [kernel.vmlinux] [k] bio_alloc_bioset > + 2.70% io_uring [nvme_core] [k] nvme_setup_cmd > + 2.59% io_uring [kernel.vmlinux] [k] blk_mq_make_request > + 2.46% io_uring [kernel.vmlinux] [k] io_prep_rw > + 2.32% io_uring [kernel.vmlinux] [k] io_read > + 2.25% io_uring [kernel.vmlinux] [k] blk_mq_free_request > + 2.19% io_uring [kernel.vmlinux] [k] io_put_req > + 2.06% io_uring [kernel.vmlinux] [k] kmem_cache_alloc > + 2.01% io_uring [kernel.vmlinux] [k] generic_make_request_checks= > + 1.90% io_uring [kernel.vmlinux] [k] __sbitmap_get_word > + 1.86% io_uring [kernel.vmlinux] [k] sbitmap_queue_clear > + 1.85% io_uring [kernel.vmlinux] [k] io_issue_sqe >=20 >=20 --=20 Pavel Begunkov --3uFrkmDlTApU8qTA9VHwffF0MAgdcG3lG-- --AzNQoLv2McupmGhnzJNm9urb2gLHcd6HN Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEE+6JuPTjTbx479o3OWt5b1Glr+6UFAl3+Vb4ACgkQWt5b1Glr +6VXmw/+LRykB19lWgcVBsDxfV/IHwejEFsVMlB00nBZWGiaqBM5OvrpQ9cTF/tO LPcKZweG0Nt8o5x/PAypzdjU26rSn33mPpqn7SK6fbO9x/mxxykBGyNm9NCdhG3y NN2vMFRyWH0C0XFVyxX+Mkxetj6PUvlPmRtfbOocKkac5jnuNPL6e1nMEHanDLc2 b9M4t64xHH61Kkhj0/8fEvhoyMi+kaS2JpsvsjhkswGrJSGKERyWP45CM2S+D3AC HW7h/0huSN3snpZZJk1ZHlL+OhspNflEhtf5vDUQoBDu0SsGLzXUtutFkpNLoe0c G7B2yLNNH6Q2YLLRwcS5y8qeujW7EqPR/YbdRwYo+wmSXuxK4Aqwjh1KWxh7AJOX kVOmXitJvb9154OeEQ/Fk0SNPH2TlOeNRJDxZ63yx357uCHVnNxhD7YqURxPsen3 CzVi/OV5Gnn65DXeEYj3uSTC9UDRy6QB3Qco1SPt/Gtg9PIpwR0NYmzt56FiB2C3 43vtp7rc3VsVPqoQ1UC/21pGgZFnuOo24npQiNtTFf1PKFNIZpmPEEs3DXbENKGr SSi2mCUuhx1PG08iuBL6fB+Mq6MVA3zCp0UapKPRhFYSldJjdiJLveEIKNBQWvs7 83E8C0736CE0/vH0a9VQv63CdrF5Vnddk8yWX/HgdMZiJgbN5Nw= =D3tA -----END PGP SIGNATURE----- --AzNQoLv2McupmGhnzJNm9urb2gLHcd6HN--