From nobody Mon Feb 9 08:53:48 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D6D3EB64D9 for ; Mon, 10 Jul 2023 22:34:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230344AbjGJWeq (ORCPT ); Mon, 10 Jul 2023 18:34:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231124AbjGJWeg (ORCPT ); Mon, 10 Jul 2023 18:34:36 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F87A10DA for ; Mon, 10 Jul 2023 15:34:08 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-5704e551e8bso59419597b3.3 for ; Mon, 10 Jul 2023 15:34:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1689028447; x=1691620447; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=eMznknX6LhCZzxkpGK1anYqC2AReGQzyhNKGt0dhRMs=; b=BtdvUbd29zwhezN9vWnqcJKpf0bV2LKN/+c8VWC9oiyT99FFcNEJDOvUA5o+m21DRJ e9aNejKksk1rdwKl8O1MZ9yP/O1OkMbpULehfNB94qYTmzji2HykYi+osFgOuhdAF+qD KGUZyMgcGBl8J91gT7Vb/XlYX07mdXJEBkEmKhCq++SE1RIb3ka/J0r4X0WZmUp1LyEo SjYNX6E3UyUwTUHmBfJ7fNPviqSEF3jRznivgjuuqoMmWVaZBvnRoFgKdOZiBTRle0wA 2DGPZWSVDlrn2z8oZhGDAjAlxNPaIc+/JHcTW0CD86xRjmhJfySPnG/Os836KYedkH0U WpvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689028447; x=1691620447; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=eMznknX6LhCZzxkpGK1anYqC2AReGQzyhNKGt0dhRMs=; b=HNcV9rwUrOdCEsdrF1pJTnGlIZcmegSJjd/TSsnoRNEByLTDDd0O+toZZxFZQDAAon 37TfcE2gC3Nzmr1zceky7/Y3mFzP7kqXJ19vSU5SHQH9TIKMO5u7xWgojSRePVH4pKFu RWX6QWu/ACooaAHDm36ASEdJKoGHkF7stD+g3uirbHEdG6O4HbMbcIFlrDfk1SQYCo16 ggIvpwudK7zqWCg8HUE2Mmq3Bh6jhZX9K4GpkjWwp5D9LUnbTH0GiCAxgKsyF1bYp1T0 JED7m0Dpic/jYC1LqAmEAxZ0HQS+JRQkxsm1hKoAirAn7Do1YR+2h8tDk89lMaDEU8NV +hmg== X-Gm-Message-State: ABy/qLbf33SXwZIbN4v7nsQgppmoGMsDsL9PPciEoPoohd8fuRFxHPn9 A29WZB6tk2I4aKVY2KamM8tMSbvQMFpYhLQg5Z9NwGdx4R3492dnChxOWbfCN2KcbyHB/F06hpH +Ipf5yQ9FQiQw2pQ76jmpz8QSeP/X8C8x2WlvViY/Y8YojdCnYbjitVKAEFaQGhhAczmw5Lyf6p j+GTR5fto= X-Google-Smtp-Source: APBJJlHZxtTyAip5d5fJgZLpVb+rUoGbj/Pap2HolJ5oEOujITpsR+hl7i9eHYLZIaU+exV6ykL+cfJhHKzieUdutg== X-Received: from almasrymina.svl.corp.google.com ([2620:15c:2c4:200:4c0f:bfb6:9942:8c53]) (user=almasrymina job=sendgmr) by 2002:a81:e90b:0:b0:573:285a:c2a3 with SMTP id d11-20020a81e90b000000b00573285ac2a3mr95478ywm.1.1689028446916; Mon, 10 Jul 2023 15:34:06 -0700 (PDT) Date: Mon, 10 Jul 2023 15:32:57 -0700 In-Reply-To: <20230710223304.1174642-1-almasrymina@google.com> Mime-Version: 1.0 References: <20230710223304.1174642-1-almasrymina@google.com> X-Mailer: git-send-email 2.41.0.390.g38632f3daf-goog Message-ID: <20230710223304.1174642-7-almasrymina@google.com> Subject: [RFC PATCH 06/10] net: add SO_DEVMEM_DONTNEED setsockopt to release RX pages From: Mina Almasry To: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, netdev@vger.kernel.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Mina Almasry , Sumit Semwal , "=?UTF-8?q?Christian=20K=C3=B6nig?=" , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jesper Dangaard Brouer , Ilias Apalodimas , Arnd Bergmann , David Ahern , Willem de Bruijn , Shuah Khan , jgg@ziepe.ca Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add an interface for the user to notify the kernel that it is done reading the NET_RX dmabuf pages returned as cmsg. The kernel will drop the reference on the NET_RX pages to make them available for re-use. Signed-off-by: Mina Almasry --- include/uapi/asm-generic/socket.h | 1 + include/uapi/linux/uio.h | 4 +++ net/core/sock.c | 41 +++++++++++++++++++++++++++++++ 3 files changed, 46 insertions(+) diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/s= ocket.h index 88f9234f78cb..2a5a7f5da358 100644 --- a/include/uapi/asm-generic/socket.h +++ b/include/uapi/asm-generic/socket.h @@ -132,6 +132,7 @@ =20 #define SO_RCVMARK 75 =20 +#define SO_DEVMEM_DONTNEED 97 #define SO_DEVMEM_HEADER 98 #define SCM_DEVMEM_HEADER SO_DEVMEM_HEADER #define SO_DEVMEM_OFFSET 99 diff --git a/include/uapi/linux/uio.h b/include/uapi/linux/uio.h index 8b0be0f50838..faaa765fd5a4 100644 --- a/include/uapi/linux/uio.h +++ b/include/uapi/linux/uio.h @@ -26,6 +26,10 @@ struct cmsg_devmem { __u32 frag_token; }; =20 +struct devmemtoken { + __u32 token_start; + __u32 token_count; +}; /* * UIO_MAXIOV shall be at least 16 1003.1g (5.4.1.1) */ diff --git a/net/core/sock.c b/net/core/sock.c index 24f2761bdb1d..f9b9d9ec7322 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1531,7 +1531,48 @@ int sk_setsockopt(struct sock *sk, int level, int op= tname, /* Paired with READ_ONCE() in tcp_rtx_synack() */ WRITE_ONCE(sk->sk_txrehash, (u8)val); break; + case SO_DEVMEM_DONTNEED: { + struct devmemtoken tokens[128]; + unsigned int num_tokens, i, j; =20 + if (sk->sk_type !=3D SOCK_STREAM || + sk->sk_protocol !=3D IPPROTO_TCP) { + ret =3D -EBADF; + break; + } + + if (optlen % sizeof(struct devmemtoken) || + optlen > sizeof(tokens)) { + ret =3D -EINVAL; + break; + } + + num_tokens =3D optlen / sizeof(struct devmemtoken); + if (copy_from_sockptr(tokens, optval, optlen)) { + ret =3D -EFAULT; + break; + } + + ret =3D 0; + + for (i =3D 0; i < num_tokens; i++) { + for (j =3D 0; j < tokens[i].token_count; j++) { + struct page *pg =3D xa_erase(&sk->sk_pagepool, + tokens[i].token_start + j); + + if (pg) + put_page(pg); + else + /* -EINTR here notifies the userspace + * that not all tokens passed to it have + * been freed. + */ + ret =3D -EINTR; + } + } + + break; + } default: ret =3D -ENOPROTOOPT; break; --=20 2.41.0.390.g38632f3daf-goog