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Thu, 07 Nov 2019 01:24:23 -0800 (PST) To: Jens Axboe , io-uring@vger.kernel.org References: <4e41bfad-d7ec-6381-741c-0261f321617a@kernel.dk> 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: fixup for "io_uring: allocate io_kiocb upfront" Message-ID: <2ed217ce-6a17-7364-6752-73b16ff6fc2f@gmail.com> Date: Thu, 7 Nov 2019 12:24:05 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <4e41bfad-d7ec-6381-741c-0261f321617a@kernel.dk> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="eGeNJNYnWQgwuQLIXm81Rce6uVWnUw4zJ" 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) --eGeNJNYnWQgwuQLIXm81Rce6uVWnUw4zJ Content-Type: multipart/mixed; boundary="AzFlLVkyFY0Btcr0LcEgHApAfHDq4lYiH"; protected-headers="v1" From: Pavel Begunkov To: Jens Axboe , io-uring@vger.kernel.org Message-ID: <2ed217ce-6a17-7364-6752-73b16ff6fc2f@gmail.com> Subject: Re: fixup for "io_uring: allocate io_kiocb upfront" References: <4e41bfad-d7ec-6381-741c-0261f321617a@kernel.dk> In-Reply-To: <4e41bfad-d7ec-6381-741c-0261f321617a@kernel.dk> --AzFlLVkyFY0Btcr0LcEgHApAfHDq4lYiH Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 07/11/2019 06:20, Jens Axboe wrote: > Pavel, >=20 > I didn't read this one closely enough for the latest change, we > can't just return -EAGAIN if we don't submit anything, we have to > explicitly do it for just the failure case of not getting a request. > I'm going to fold in this incremental: >=20 My bad, it should be a common case to have @to_submit >=3D nr_sqes_in_rin= g (i.e. I don't care, just submit all). Thanks for fixing it. Also, if it submitted @n (>0), and can't allocate for @n+1, I'd rather prefer to get submitted count. BTW, I found this "one return value for both submit() and wait_cqes()" a bit confusing. In addition, there is reporting through cqe, and sometimes they could be interchanged like in this case. It's getting even more trickier with links. Maybe, you have some write-up on what to expect from this perspective? Don't remember it to be in the pdf. > diff --git a/fs/io_uring.c b/fs/io_uring.c > index 951fd09612ec..af8a673c618f 100644 > --- a/fs/io_uring.c > +++ b/fs/io_uring.c > @@ -2978,8 +2978,11 @@ static int io_submit_sqes(struct io_ring_ctx *ct= x, unsigned int nr, > unsigned int sqe_flags; > =20 > req =3D io_get_req(ctx, statep); > - if (unlikely(!req)) > + if (unlikely(!req)) { > + if (!submitted) > + submitted =3D -EAGAIN; > break; > + } > if (!io_get_sqring(ctx, &req->submit)) { > __io_free_req(req); > break; > @@ -4316,8 +4319,6 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd,= u32, to_submit, > cur_mm =3D ctx->sqo_mm; > submitted =3D io_submit_sqes(ctx, to_submit, f.file, fd, > &cur_mm, false); > - if (!submitted) > - submitted =3D -EAGAIN; > mutex_unlock(&ctx->uring_lock); > } > if (flags & IORING_ENTER_GETEVENTS) { >=20 --=20 Pavel Begunkov --AzFlLVkyFY0Btcr0LcEgHApAfHDq4lYiH-- --eGeNJNYnWQgwuQLIXm81Rce6uVWnUw4zJ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEE+6JuPTjTbx479o3OWt5b1Glr+6UFAl3D4rUACgkQWt5b1Glr +6UM+A/8CoYq0INEkNzLO8aPXH2yRzE3gBlTbMoNUllI/vZlF7HQFPouAuq9SxEV qI6/KuUPTH82XQXw1ZNwSDLOefnyLoixF6DQPCyogrgfGvfNDM1BECkT+wXlJm/R a7QFmvBo6ZjybpC2FYZI76a3e3+JgZ74d3mDDz7xyqzzimOvIyUnZW1ycwyET6fv Orw/5ojmy7wymRXuxZ+PH+M7u6t3+qcwXkWuweaMAV0SZHxcupLURUMJWntM98Su ZkcHrJemROr8R0+EFGgCg0sIAmujzrA1pGzN6v+Y2cfBaCF93jH31xosbN1HFwpC ix7Mt1cClAFJr3rPL2pD3jGy5jV+xsFQyd3xKF76C6xFYjJU1aWFU6fpsNJ9eGyg cJa5BHg+7UvFdE1Y+4pzceBrVEffyxjOfyjM92dbdEGoN6E8PPvA20jvRLV6w0rW eC1HkMVDUHExWQo6F2ypAk6mEQa8j+/l7nIARah2ZxodDOcCPa2luTlBiVzfdwV+ a4KT9UHNcnRsE3eeqZH8vR5sSaOW4bYS97qOr0ksE0RJeAoSMRGRZGTJQEdDVt+E c422UoMaKlHWGna1g3KbEu78CsRK0J0lBRwd8szTAOtejU6ryCC7x+hcVI0GaIWs VTgv4LhSKZj2EALSFWdPSM6QgEZN3eHTJXfTxliFw1TS3vDM8DY= =TUhU -----END PGP SIGNATURE----- --eGeNJNYnWQgwuQLIXm81Rce6uVWnUw4zJ--