From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8089E1607AC; Thu, 18 Sep 2025 15:07:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758208058; cv=none; b=vC/fq12ScbsdzSJ9sLs0vIzguqZsjsZ8jJERLzhV+uP3I950VSWRLkfq90kjAtO2IbcEq3u+JTP8ZxwIo/2D/iaxJLyswab9mFoFfYgDQdfjgviVKXe+jq/LdZEGP/mllUoyxMjNT8bR7T/skq9jMAoG06WW6Km4Ldm7AwGHC2I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758208058; c=relaxed/simple; bh=sW/npsoqVvH2jZ1iYFeywDG41QnbgIzfrJf90iHIx94=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eYNuEjCN9+jJskTHbs4XDGmPeKXXXaiW5hh2KJ8LgwellK4VtkyC+P96X+4e8gA4bH0Dja1NqyfhvBApY4kvVMCw69FXZ9n/BP3//g0EPlBvILyyQ8lkp/bnQY+AI1FmOJ3YxlZ0gwRTeAHecT4o1J1HNjqSdz+7Qkn/ktQ0z08= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kwZnl0bg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="kwZnl0bg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6AD3CC4CEEB; Thu, 18 Sep 2025 15:07:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758208057; bh=sW/npsoqVvH2jZ1iYFeywDG41QnbgIzfrJf90iHIx94=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kwZnl0bgzIv5G9GpaNIDQbuvO9HddfBAxifrvDjM5Ugs42X76RrBv51TpbdZm5Y1L mHQv8IAwm4Xd7QqDtWeChSyd0hXizLPuB2fIG09/9z0/ttqtVToJnG0xDvM7xZQN0y m2pRwIJx1HdEaHaPQRUPdlZi+AeKJfLhgt5uRqabPJ95o3Ib7FYa3KR/mz++sX1Lka ouGGsFcEH95nRzAxLtCilfOwp6ls1KG4xphq5ucvhDweyDOeUjwEszovJaqSF1pTVe 1JVb1CKf7Cti5yxGTvJENeZRlV2K3Kjermk5ncw0x/qepBF3oLDwfHUQsk+YORmcjv fkxEbB7s/6Ojg== Date: Thu, 18 Sep 2025 16:07:27 +0100 From: Simon Horman To: Tariq Toukan Cc: Catalin Marinas , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Andrew Lunn , "David S. Miller" , Saeed Mahameed , Leon Romanovsky , Mark Bloch , netdev@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, Gal Pressman , Leon Romanovsky , Jason Gunthorpe , Michael Guralnik , Moshe Shemesh , Will Deacon , Alexander Gordeev , Andrew Morton , Christian Borntraeger , Borislav Petkov , Dave Hansen , Gerald Schaefer , Vasily Gorbik , Heiko Carstens , "H. Peter Anvin" , Justin Stitt , linux-s390@vger.kernel.org, llvm@lists.linux.dev, Ingo Molnar , Bill Wendling , Nathan Chancellor , Nick Desaulniers , Salil Mehta , Sven Schnelle , Thomas Gleixner , x86@kernel.org, Yisen Zhuang , Arnd Bergmann , Leon Romanovsky , linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Mark Rutland , Michael Guralnik , patches@lists.linux.dev, Niklas Schnelle , Jijie Shao , Patrisious Haddad Subject: Re: [PATCH net-next V3] net/mlx5: Improve write-combining test reliability for ARM64 Grace CPUs Message-ID: <20250918150727.GX394836@horms.kernel.org> References: <1758178883-648295-1-git-send-email-tariqt@nvidia.com> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1758178883-648295-1-git-send-email-tariqt@nvidia.com> On Thu, Sep 18, 2025 at 10:01:23AM +0300, Tariq Toukan wrote: > From: Patrisious Haddad > > Write combining is an optimization feature in CPUs that is frequently > used by modern devices to generate 32 or 64 byte TLPs at the PCIe level. > These large TLPs allow certain optimizations in the driver to HW > communication that improve performance. As WC is unpredictable and > optional the HW designs all tolerate cases where combining doesn't > happen and simply experience a performance degradation. ... > Signed-off-by: Patrisious Haddad > Reviewed-by: Michael Guralnik > Reviewed-by: Moshe Shemesh > Signed-off-by: Tariq Toukan > --- > drivers/net/ethernet/mellanox/mlx5/core/wc.c | 28 ++++++++++++++++++-- > 1 file changed, 26 insertions(+), 2 deletions(-) > > Find V2 here: > https://lore.kernel.org/all/1757925308-614943-1-git-send-email-tariqt@nvidia.com/ > > V3: > - Move the new copy assembly code to be inline, within the same file it > is used. > - Use ".arch_extension simd;\n\t" to avoid the need for separate file > and special compilation flags. Hi Tariq, Patrisious, all, This is not a full review - although I've been following this patch with much interest, I don't feel qualified to provide one. But what I can do is be the poor soul to report that unfortunately the patch doesn't compile against net-next. So at some point it will need to be rebased and reposted. Thanks for your persistence on working on this, it is indeed a nettlesome issue. -- pw-bot: changes-requested