From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E35CE50256D for ; Thu, 15 Oct 2026 13:02:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792069351; cv=none; b=D9KySgzvO2NFY0jM7jgNUWnwGNMAq6Dlrz7cAgtFfBLNJCka0qyGhIDKqcb9jmQASsvK2BB0ZSY717YTChZAt4nGvhVwqAJdSBJFC6Zsw/jAi8uNqMwXIEH8G4GgXqHKv1dal634JiXEH7h8cv8Gj+aMOOzWOurcwaoG2Pc734U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792069351; c=relaxed/simple; bh=8E6F6bCaQwEk5CCxJA9DCsKfHiQmPbmheJmqhlz6q0w=; h=Message-ID:From:Subject:To:In-Reply-To:References:Content-Type: Date; b=Jk/CxmxRC/cHgXczTujRnHoAfgrvnEuisulMESYlWM2Z7yFXsC4T3q9W9GtAV16Q2vnubdJ7VLA8b4xSn9tSik9pPZ8L1MIN3C+a+rg4l1AwOujvFkgPR+VLC8irmdk2Pps1wPuBNfMU84cQr7Y0Ksb09S8oDNYuwM50kwzQsnU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SOV4rIll; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SOV4rIll" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2C3981F000C4; Thu, 15 Oct 2026 13:02:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792069350; bh=8E6F6bCaQwEk5CCxJA9DCsKfHiQmPbmheJmqhlz6q0w=; h=From:Subject:Reply-To:To:In-Reply-To:References:Date; b=SOV4rIllA8kyqRUhfHSIYF4L76Mku7XWd0mdOH7fLbLCPNaVVgtcKjhMgb7t00O0x 30ieNghi/QstjwKYrxBcP31MHqd0Yay0SK50FB2GlOqjNi8VYR0HfyoVwb6U/UFlbP dFWBmGdOQZTRf0FPlhBXBHZLsRN+6bzVupO+dl+xOM2GUEQo6Q1rs5YVlroWb56f1T OIGdjHLlfQ2FapMccKEYshQQLEOmg2RKQuHQHYXRkhak34bKiNYi7OPtcJs9kNW1JT xeEWea47Ot476jI/jR1qXwiueuSLFSca/robUd8IBI77aOId0w9nj2jdgUjG9XRhpZ Y5HaMOAfuT3mw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH RFC 2/3] RDMA/srp: Post command IUs inline Reply-To: sashiko-reviews@lists.linux.dev To: "Andrei-Alexandru Bleortu" , linux-rdma@vger.kernel.org In-Reply-To: <20261015125118.2966247-3-me@andrei-z.com> References: <20261015125118.2966247-1-me@andrei-z.com> <20261015125118.2966247-3-me@andrei-z.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 15 Oct 2026 13:02:29 +0000 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > srp_post_send() posts every information unit by reference, and the QP > asks for no inline data. Before the HCA can send an SRP_CMD it > therefore has to DMA-read the IU from host memory, and that read is > on the latency path of every command. >=20 > Ask for SRP_MAX_INLINE_DATA bytes of inline data when creating the QP, > enough for an SRP_CMD with an additional CDB and an indirect table of > two descriptors (116 bytes). If the device refuses, ask for less. Intel > irdma has a fixed limit of 216, 101 or 48 bytes, depending on the > generation, and Alibaba erdma one of 96. On those devices, found by > vendor ID, try these limits first, then step down 16 bytes at a time to > none. libfabric's verbs provider also probes the inline limit by trial > QP creation. The RDMA/CM and IB/CM QP creation paths move into > srp_create_qp() so the retries cover both. Post an IU without immediate > data with IB_SEND_INLINE when it fits in the inline size the device > granted. >=20 > Providers copy inline data from sg_list[].addr as a kernel virtual > address, so the inline path points iu->sge[0] at iu->buf. > srp_post_send() resets it to iu->dma on every post, and iu->dma keeps > the mapping. >=20 > Assisted-by: LLM > Signed-off-by: Andrei-Alexandru Bleortu Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261015125118.2966= 247-1-me@andrei-z.com?part=3D2