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 0C1D715696E; Wed, 25 Sep 2024 09:26:50 +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=1727256411; cv=none; b=N/S+BQ9Dpm40YFC/5OYUt5QC7mV4EzQBH/n2fyWwzxbHWtHK/x36g0juNs9RmQV3PZcnudoAKO8T/9TIxt6zWdM8sSbhrelKzcBaqr+yzuU9TD90fPhV0hhagcIWPOBvKBnnLYe9jmCslDhNu566mtg8NmKXMzp3k3FSp59b7Es= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727256411; c=relaxed/simple; bh=BpYw0/PY3nUKuGYmrFd2VEU+1WnGJEzl1EFkES0lhdo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=l5aUEbN9T3yu49E0js7Vkd27XVGmb4/c9+BR+Bv2/25lZbVpMxemt2/nsW7mulUtW4WrpcwxlSI8O9xCc8ioX94nbq4qD4uOaWmaa5pmD4o1omsZY2eAsg9Y/5bLes4hhCEg5FEi8tuDgugkITXTaqt421d2YT3iz2koErJBDy8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=czXe/MS5; 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="czXe/MS5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02C31C4CEC3; Wed, 25 Sep 2024 09:26:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727256410; bh=BpYw0/PY3nUKuGYmrFd2VEU+1WnGJEzl1EFkES0lhdo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=czXe/MS5lkFRAI+SEkAnjfhu8tVNguHaf8ImTy0yb9fzio2as+fvoECKpeYtR2uze 4Gm48t6UhqC+fUbmo6hJObNdcnYvvnIuxZ/SDMaFFTyo3RTKcgyq73zPI0unoMatel Ya2XizH2jOdH/+Ne4Ncx2ZoPFx5f1X9FgRWOepGfIghxxddlQCLaOiqd2J8qIzis1A SEYReiUlvGpQbrOperzsiZjwH8kIHx1Sog08usRPqAY2PfermmyAHEvzLKKMBIg518 MsYUCjFuiMItHtyzoq+jTkx+KgNYQdNsz94t2UlGnymutiteqkUL4TzyvvhY0zKmHI quDahHav2wtIw== Date: Wed, 25 Sep 2024 12:26:45 +0300 From: Leon Romanovsky To: Zhu Yanjun Cc: Haakon Bugge , Christoph Hellwig , Jason Gunthorpe , Allison Henderson , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , OFED mailing list , "linux-kernel@vger.kernel.org" , "netdev@vger.kernel.org" , "rds-devel@oss.oracle.com" Subject: Re: [MAINLINE 0/2] Enable DIM for legacy ULPs and use it in RDS Message-ID: <20240925092645.GD967758@unreal> References: <525e9a31-31ee-4acf-a25c-8bf3a617283f@linux.dev> <1ad540cb-bf1b-456b-be2d-6c35999bdaa8@linux.dev> <66A7418F-4989-4765-AC0F-1D23342C6950@oracle.com> <5b86861b-60f7-4c90-bc0e-d863b422850f@linux.dev> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5b86861b-60f7-4c90-bc0e-d863b422850f@linux.dev> On Wed, Sep 25, 2024 at 10:04:21AM +0800, Zhu Yanjun wrote: > 在 2024/9/24 23:16, Haakon Bugge 写道: > > > > > > > On 24 Sep 2024, at 15:59, Zhu Yanjun wrote: > > > > > > 在 2024/9/24 14:54, Christoph Hellwig 写道: > > > > On Tue, Sep 24, 2024 at 09:58:24AM +0800, Zhu Yanjun wrote: > > > > > The users that I mentioned is not in the kernel tree. > > > > And why do you think that would matter the slightest? > > > > > > I noticed that the same cq functions are used. And I also made tests with this patch series. Without this patch series, dim mechanism will not be invoked. > > > > Christoph alluded to say: Do not modify the old cq_create_cq() code in order to support DIM, it is better to change the ULP to use ib_alloc_cq(), and get DIM enabled that way. > > Hi, Haakon > > To be honest, I like your original commit that enable DIM for legacy ULPs > because this can fix this problem once for all and improve the old > ib_create_cq function. > > The idea from Christoph will cause a lot of changes in ULPs. I am not very > sure if these changes cause risks or not. > > Thus, I prefer to your original commit. But I will follow the advice from > Leon and Jason. Christoph was very clear and he summarized our position very well. We said similar thing to SMC folks in 2022 [1] and RDS is no different here. So no, "old ib_create_cq" shouldn't be used by ULPs. Thanks [1] https://lore.kernel.org/netdev/YePesYRnrKCh1vFy@unreal/ > > Zhu Yanjun > > > > > > > Thxs, Håkon > > > >