From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f50.google.com (mail-ej1-f50.google.com [209.85.218.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 36776286D73 for ; Thu, 25 Sep 2025 09:56:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.50 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758794197; cv=none; b=nlyqUnvw27sU8898hSowBliDr68EKIRs0JxncKmvvp4ygSKMBsML977z7AnblSlmrKI8t5Q5An+F9oUbTmRr87K21BZLHC8I9iWvcVqO5B6PFskrBwpRDQXwZSygDNUXHjmoNyR9z7yvw4GkQ+S8abGcChJ/7NqAxQKh2BcWcWQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758794197; c=relaxed/simple; bh=GrzEpmFKJ08dCvz23e91yU1k/k8cQAq/gU1NwyJoAlE=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=gNDEoxyrJMgmLmTMDKTnKbA0Mwol+R/AAnkGa2YY3SMfaI0EghiINiTZoyeQisWrXc6oAyQT8jiW09Z2TjpuVRD1Xda1ykgN6fOXix08k7k47UNncDJXaEG3W4knXdXEkTVghBdsqGGvXnWo3VxnN5Y4Rt/roGIxIeTJN2gsTiI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=cloudflare.com; spf=pass smtp.mailfrom=cloudflare.com; dkim=pass (2048-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b=JUPc1AGF; arc=none smtp.client-ip=209.85.218.50 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=cloudflare.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=cloudflare.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b="JUPc1AGF" Received: by mail-ej1-f50.google.com with SMTP id a640c23a62f3a-b35f6f43351so68408266b.1 for ; Thu, 25 Sep 2025 02:56:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google09082023; t=1758794193; x=1759398993; darn=vger.kernel.org; h=mime-version:message-id:date:references:in-reply-to:subject:cc:to :from:from:to:cc:subject:date:message-id:reply-to; bh=GrzEpmFKJ08dCvz23e91yU1k/k8cQAq/gU1NwyJoAlE=; b=JUPc1AGFfk3bjU6Ufb4JhAfMZKUcOfnL3Hyw2J55Hdl+IopjX5xQXs6bGKpOo3Wj19 5wH17qzQO3PyOqz9/gHl9SCQrZoDwYRoD8BCpGzidGZnYKHM6l46avJM1ib3jHeN8xPx JkFc4xHda/XzmLmF4rkDUky8YDm49FcYjsgB5ucLyCpE+PEkBPkptNHoz9G60HzI8ogc +d31ZbA9MyRPdFjQ2dOe5K1BppfQo+s1v8nT8F1FQ7CtxrZnImqew/vnelt+zLn5qbir H1NMs7ZcKcFpwkDOE0Rz1m8TXnVJxz3JIXb7BVxHS5/5/19tQv0Sm8vmLaM0CzR1IXG0 nTZg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758794193; x=1759398993; h=mime-version:message-id:date:references:in-reply-to:subject:cc:to :from:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=GrzEpmFKJ08dCvz23e91yU1k/k8cQAq/gU1NwyJoAlE=; b=I42TQhdWk9VfGfOpOsN+Q4hOQAm697wXc0PiipEVdVAPq4UtY90z4rAjvLJYXou0XB Ry7Dt484b1yEExVBX7cClsBvphSiDEQZIUU4no0v2UfVkhLv8h1r4ERfgaBqU7d3rGBV TXolp7N1HxjVLD0d1mpXRhL2zgFM/hQkhwyNW9XFOoj2xWEDZLb6UZhB6gtV21LWBa/u NWL1JWUu6klojrT3NoYb/s9jCWNEF848YWBkWD43qLGZGFg7PC/Y6wDcyqBHK3uw2YEE /yvhBuvZ3b/Exu23UtSJLvPTyohDDZBbn+YjQydyRqdMtj280gU0ozgSQu1W0ST+/YUk 7nNg== X-Forwarded-Encrypted: i=1; AJvYcCVCrV+HCYig5pWJ6kytDBZmplxG0QSuI4Gih/4CmOOPxkW6f3Uc78VLTBr30bkEOL+KaeWB/t0=@vger.kernel.org X-Gm-Message-State: AOJu0YwMSnODFmNeaUiqjtzCo/DiFhJUenmNr8JV1MrRSrkJkEi3BkeV Cc69EEsdTL8QOClzVKpQN3aBHFK42/Es0D4X12qshSWaQrkY0uxWsCkpDNwMF//fRpk= X-Gm-Gg: ASbGnctjZUyDoqNf1ya05AsKEVKcUyUS3D3A8V4vjIZMl1cl/4zmguefBzInD0vGlDI b+NqzKcDxaSThRxDg9bUCZxMjdp72h1t/ZLxmU21lHPLp/NYR9EfWwu8J2m3FYieWgEKqtADX+p qb1Hm+4gfpLY+Wd552bhmURus3Ue1omgLlOFHz/M9TCsgK25qQthOgTPWwlXoEsG2wgDXVYXM4Z d/tUomNHxlOv+MJ7Mjp0Pp45hry7yLDGd8t3KfwRQyA6lWRFNKDflcTOg4aGk9CHsI3Dkaq9WDD D+RqJ8qSfJ+V4j9f7OOy3xu75c2YkwEh9/gatB7v5LkCtulUAxcRWGQliXHkr6MDjP7IA2vOpl9 cEXGm/hwOf8MdKtg= X-Google-Smtp-Source: AGHT+IGKjMEcIpRr3EEKuOD0rD2TCapZ8lHREep6jZzrzi+iYypOPWa4NYN3C7vTMs0QmrtjLXw5IA== X-Received: by 2002:a17:907:9719:b0:b04:6973:1ee9 with SMTP id a640c23a62f3a-b34b7105a20mr277447566b.16.1758794193333; Thu, 25 Sep 2025 02:56:33 -0700 (PDT) Received: from cloudflare.com ([2a09:bac6:d677:295f::41f:5e]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-b3544fd0a54sm135005666b.86.2025.09.25.02.56.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 25 Sep 2025 02:56:32 -0700 (PDT) From: Jakub Sitnicki To: Michal Kubiak Cc: intel-wired-lan@lists.osuosl.org, maciej.fijalkowski@intel.com, aleksander.lobakin@intel.com, jacob.e.keller@intel.com, larysa.zaremba@intel.com, netdev@vger.kernel.org, przemyslaw.kitszel@intel.com, pmenzel@molgen.mpg.de, anthony.l.nguyen@intel.com Subject: Re: [PATCH iwl-next v3 0/3] ice: convert Rx path to Page Pool In-Reply-To: <20250925092253.1306476-1-michal.kubiak@intel.com> (Michal Kubiak's message of "Thu, 25 Sep 2025 11:22:50 +0200") References: <20250925092253.1306476-1-michal.kubiak@intel.com> Date: Thu, 25 Sep 2025 11:56:31 +0200 Message-ID: <877bxm4zzk.fsf@cloudflare.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Thu, Sep 25, 2025 at 11:22 AM +02, Michal Kubiak wrote: > This series modernizes the Rx path in the ice driver by removing legacy > code and switching to the Page Pool API. The changes follow the same > direction as previously done for the iavf driver, and aim to simplify > buffer management, improve maintainability, and prepare for future > infrastructure reuse. > > An important motivation for this work was addressing reports of poor > performance in XDP_TX mode when IOMMU is enabled. The legacy Rx model > incurred significant overhead due to per-frame DMA mapping, which > limited throughput in virtualized environments. This series eliminates > those bottlenecks by adopting Page Pool and bi-directional DMA mapping. > > The first patch removes the legacy Rx path, which relied on manual skb > allocation and header copying. This path has become obsolete due to the > availability of build_skb() and the increasing complexity of supporting > features like XDP and multi-buffer. > > The second patch drops the page splitting and recycling logic. While > once used to optimize memory usage, this logic introduced significant > complexity and hotpath overhead. Removing it simplifies the Rx flow and > sets the stage for Page Pool adoption. > > The final patch switches the driver to use the Page Pool and libeth > APIs. It also updates the XDP implementation to use libeth_xdp helpers > and optimizes XDP_TX by avoiding per-frame DMA mapping. This results in > a significant performance improvement in virtualized environments with > IOMMU enabled (over 5x gain in XDP_TX throughput). In other scenarios, > performance remains on par with the previous implementation. > > This conversion also aligns with the broader effort to modularize and > unify XDP support across Intel Ethernet drivers. > > Tested on various workloads including netperf and XDP modes (PASS, DROP, > TX) with and without IOMMU. No regressions observed. Will we be able to have 256 B of XDP headroom after this conversion? Thanks, -jkbs