From mboxrd@z Thu Jan 1 00:00:00 1970 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 6A5F8EE49B6 for ; Thu, 24 Aug 2023 22:56:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243976AbjHXWzq (ORCPT ); Thu, 24 Aug 2023 18:55:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244037AbjHXWzf (ORCPT ); Thu, 24 Aug 2023 18:55:35 -0400 Received: from mail-ej1-x631.google.com (mail-ej1-x631.google.com [IPv6:2a00:1450:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 128F11FD0 for ; Thu, 24 Aug 2023 15:55:27 -0700 (PDT) Received: by mail-ej1-x631.google.com with SMTP id a640c23a62f3a-9936b3d0286so37412166b.0 for ; Thu, 24 Aug 2023 15:55:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1692917725; x=1693522525; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=LRwqn+8y3sMpl97JXgW1Kcuei5VeXjUdmpcF0r4gMS0=; b=DXyyYBC1SzcFWlLWIMc3z5yrf2YD+w6N5PB0/6pdMK2bAFSDSEzcDYS73L0MFyF9Zf MIWQuoFocHzrjT3DMJ9itefeYA657qBPDC6+zuPDQjEcw0Wv74xjfzy8Repge4yChXhp RQyfpD1L9bDlN7zg/vHMzMvM/gxCCx0s31Yuu8Cv9Z7R+UlhjG0q2pL0dWVofIDBZrTG YvjhxqlHNoWqOqAXJeCuPH9xlHm7GdmWCn7svctIwZyuZEBjMa4dcUi6HfsiG/RgdPif 76R/vxUwYGdBj0PnqIbnh/zQYnypaFBo/IQmOuef58rFTr1r7fP2a6Lt4NfbUzaT/qlK yEew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692917725; x=1693522525; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=LRwqn+8y3sMpl97JXgW1Kcuei5VeXjUdmpcF0r4gMS0=; b=jfWfdikrXkFuHo9nRXiiwWUcZvhYNISBkVoxelu0k1SxUfxrLaK54s7DB/pkkYdFvF wKDOuLrWz62nlMtPWbgeMNejVbqHKrfl5PZB5BfQHQya8QUNTV3n2EC4Sbnp25oo50XX LXa5DNFG9Ll8YpiAIpIe9qJAlUeNe1XFsb9BRFEROo1r+jR9lsi6aprxMh32qLXiKWyK pXPSs/bR1frhXIfuVxWSqG8+YpbbqWtXT2Hi9vPNexLp/EUePlcWsP5bcoLWUnV0On32 Ja4RUHeEyfaFpDv78Y4P27MXwHT2QsiKJ0+lqscxTNUgMs6283HjB9sZnTlk30P4IGf0 Wfag== X-Gm-Message-State: AOJu0YyJ1CewVOiqnWlDkJahzifyuN10wmCHpL3Kc+x5RO8g/al72G0V 58VaIH97L8JESWESwZSdV0EcPAQ9Rok= X-Google-Smtp-Source: AGHT+IH+fbo+C1jxd5nu0ioFzFSHzY4NOlGa83eY2ZTy2xfozVwU2qwxVCn9GpiT97THswGXibmpUw== X-Received: by 2002:a17:906:7493:b0:9a1:ca55:b668 with SMTP id e19-20020a170906749300b009a1ca55b668mr6703370ejl.59.1692917725362; Thu, 24 Aug 2023 15:55:25 -0700 (PDT) Received: from 127.0.0.1localhost ([148.252.140.69]) by smtp.gmail.com with ESMTPSA id q4-20020a170906144400b00992f81122e1sm173469ejc.21.2023.08.24.15.55.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Aug 2023 15:55:25 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com Subject: [PATCH v2 09/15] io_uring: compact SQ/CQ heads/tails Date: Thu, 24 Aug 2023 23:53:31 +0100 Message-ID: <9c8deddf9a7ed32069235a530d1e117fb460bc4c.1692916914.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Queues heads and tails cache line aligned. That makes sq, cq taking 4 lines or 5 lines if we include the rest of struct io_rings (e.g. sq_flags is frequently accessed). Since modern io_uring is mostly single threaded, it doesn't make much send to spread them as such, it wastes space and puts additional pressure on caches. Put them all into a single line. Signed-off-by: Pavel Begunkov --- include/linux/io_uring_types.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index c0c03d8059df..608a8e80e881 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -69,8 +69,8 @@ struct io_uring_task { }; struct io_uring { - u32 head ____cacheline_aligned_in_smp; - u32 tail ____cacheline_aligned_in_smp; + u32 head; + u32 tail; }; /* -- 2.41.0