From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 5324246B7E; Tue, 15 Jul 2025 13:57:46 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 777E0402D3; Tue, 15 Jul 2025 13:57:45 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by mails.dpdk.org (Postfix) with ESMTP id B42C44028C for ; Tue, 15 Jul 2025 13:57:43 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1752580663; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XcK/mgZtID6CAfrmSyCEJJwclrJdkC/OmPjWs8KbwWs=; b=i/+R7S4TzWdmk9/z+GpDLW5TfRO6AtG32stvsy8TGQ+413hpkKokp2UMLODfVElmp8WzTI Xuv5JR1aLXQn4moQ7noiwG+ESF2pDa5v44nb1W9LMgojlxXcoEXCbnm0kbRvxXWxK8gkXT sFtqBGDYNd44oQE737roGrN6W6QQEtA= Received: from mail-lj1-f197.google.com (mail-lj1-f197.google.com [209.85.208.197]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-665-RsHN3hDjN1eIQ3jhV35o2g-1; Tue, 15 Jul 2025 07:57:41 -0400 X-MC-Unique: RsHN3hDjN1eIQ3jhV35o2g-1 X-Mimecast-MFC-AGG-ID: RsHN3hDjN1eIQ3jhV35o2g_1752580660 Received: by mail-lj1-f197.google.com with SMTP id 38308e7fff4ca-32b78b5a8fcso22774751fa.1 for ; Tue, 15 Jul 2025 04:57:41 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1752580660; x=1753185460; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=XcK/mgZtID6CAfrmSyCEJJwclrJdkC/OmPjWs8KbwWs=; b=UpYbCLD12kFEHxhbpJvRWKb3eiA8oRhcQjrha2IHaQSDI9IZa3ttN1K9zdFEsejm5c ckOfOweHer5eMcv2C/MXuT3x2hlDJSoUGaE/57KGlFCqYzQklSPt0fPhCm1RyCQJvAi1 7f6pOM/7nw287UhDKdmposNunEDPf84uFZQvj7zoOarXr4UYa8AZg6/x2w93CxSbxCQ3 i0VkOftsTVWteCaH3JJOBPs5wdt2IE15XDS2MHf2v5VeJj+H8skYRmMWJ/dq04BMkajY STTCySuWFjbIZuTHGymqsmONcwwIz4a1b6sA05v8a/z8AdQ0NjtJIZfu1XOPtcJ5/Jrq LqOA== X-Gm-Message-State: AOJu0YzmTfbWhRxPexI5djbQK6mQVtD+jcaDf9siYpenkAgqaDP3rWqh L2EWuF8AB1fwXT3+8p5ffo7ypDDGoNx+EXQalexH3WUEMHI1STmn1CTCGzG27sv/sSSu0cYFVnp R+RqbcNiKTu7R8I3V+OUwETqT+YDRoIhqzSisubTk/Exaxx6f2/2/nfmJwZDT4x3vr3WT0uFT8H MAFNpl8ViFLpHHduADD6c= X-Gm-Gg: ASbGncu2sMqkqCz+0t9VUAa5gM8yF2ZqJeO+TPWahASsMGgEl6g/O/tIKgpm7AINti+ 4Y6Vxlk353umLReArnfTq9qSkc2XyyMGvO1k4ZQtjn9GMjkHfD0Y9SSPfQOTNaRuvvCSiJ4AJfI Nwsjup4MfA+br+jdqgKEhIzCM= X-Received: by 2002:a05:651c:111b:b0:32a:6b23:d3cc with SMTP id 38308e7fff4ca-3305341163emr53823791fa.25.1752580659954; Tue, 15 Jul 2025 04:57:39 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFvCfoDtZ3+cCMd9yF0ifL10ggMZ9lg0A1wwT8pZwWauIr0sjQDnQiTvwLga0S10joicvLHKg+92bhkzCV/gBQ= X-Received: by 2002:a05:651c:111b:b0:32a:6b23:d3cc with SMTP id 38308e7fff4ca-3305341163emr53823701fa.25.1752580659525; Tue, 15 Jul 2025 04:57:39 -0700 (PDT) MIME-Version: 1.0 References: <20250619071037.37325-1-david.marchand@redhat.com> <20250623135242.461965-1-david.marchand@redhat.com> <20250623135242.461965-9-david.marchand@redhat.com> <70c7ba78c4324495bfd317e38e926958@huawei.com> In-Reply-To: From: David Marchand Date: Tue, 15 Jul 2025 13:57:28 +0200 X-Gm-Features: Ac12FXzmxcgHNE4eHQYotW579qIEuQd0up0PNJQiMQtUEzN4WaRukDw_6Yfo-Dg Message-ID: Subject: Re: [PATCH v2 08/10] hash: fix unaligned access in predictable RSS To: Konstantin Ananyev Cc: "dev@dpdk.org" , "stable@dpdk.org" , Yipeng Wang , Sameh Gobriel , Bruce Richardson , Vladimir Medvedkin , John McNamara X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: JBECX2xqnmqD636XqLBnHU11SDWVWK-pWYX8vfW-QLM_1752580660 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org On Tue, Jul 8, 2025 at 7:58=E2=80=AFPM Konstantin Ananyev wrote: > > > Just wonder do you guys consider it as a real one? > > > AFAIK, all architectures that we care about do support unaligned load= for 32-bit integers. > > > > Well this is undefined behavior, regardless of what the architecture su= pport. > > And the compiler may end up generating wrong code. > > Probably, though AFAIK, we do have a lot of code that load 32-bit values = from possibly > non-aligned addresses (nearly all packet parsing does that). > I wonder why it only complained only about that one? Probably because unit tests coverage is (too) small. > BTW, would our 'unaligned_uint32_t' type help here? Since most DPDK code rely on aligned types, using an unaligned type can work if we have a function that serves as a conversion from unaligned to aligned types. In this code, since the next operation is a byte swap operation on 32bits, I don't think we have many option but to memcpy(). --=20 David Marchand