From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-182.mta1.migadu.com (out-182.mta1.migadu.com [95.215.58.182]) (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 040AB14830F for ; Fri, 7 Feb 2025 02:07:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738894057; cv=none; b=sabatzjzzDt1ONbuWKnSfRlyad3CuBHjCzfRzTEHZODkjApw+Ioi2ZbJ5TiawN6gWprhGAYBx3M+j8omat3h6ENAUyfUTn9nK+PqHX4Es1vbH+xM9imxPt7LnSxk2ks3UmvDk2uUVV3xV7/wHTI41sbc990h8blGupZTEsPqzOI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738894057; c=relaxed/simple; bh=cbxvBGUq6GAVSZjhCem/zJILOlVlSekStoMnTngw4yg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=BBiri0Hqva35H4wpOyhAELGcPXxyDRBiWJae4liWyjuh2LZ3Fg4egdMWr5i0gjq0WCRQgnkIyU8juEhkJTLKiI4zxgynVlKVBMKs5EoRBb4W1lWpk8soZDREOuClxlcqKd3RtjFmKdwxzIcWAtnZQ4GE4R7NNKziYXot+fe7v2E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=L2VLRcei; arc=none smtp.client-ip=95.215.58.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="L2VLRcei" Message-ID: <739d6f98-8a44-446e-85a4-c499d154b57b@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1738894052; 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=14LZ9ni0ciYY043ozljCMttvg3c9+WpsIO9+G/2+Bus=; b=L2VLRceidmxdp6+gZc4lhtgfGFDQbvzdw40H1NMumb/PPBJIF5nGE03uDEdCle0BVjOe1Q 8MyHxJAa9uxwrhpSuq2R16hkXKvscIyt05rds95cctns1OKDzzrrInqZJnasqFXHOihmdF hrEH4l2IZw6ZAQFLqFifPWrnk7MhlMU= Date: Thu, 6 Feb 2025 18:07:25 -0800 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next v8 10/12] bpf: make TCP tx timestamp bpf extension work To: Jason Xing Cc: Willem de Bruijn , Jakub Kicinski , davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, dsahern@kernel.org, willemb@google.com, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, horms@kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org References: <20250204183024.87508-1-kerneljasonxing@gmail.com> <20250204183024.87508-11-kerneljasonxing@gmail.com> <20250204175744.3f92c33e@kernel.org> <0a8e7b84-bab6-4852-8616-577d9b561f4c@linux.dev> <67a424d2aa9ea_19943029427@willemb.c.googlers.com.notmuch> <67a42ba112990_19c315294b7@willemb.c.googlers.com.notmuch> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Martin KaFai Lau In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 2/5/25 10:56 PM, Jason Xing wrote: >>> I have to rephrase a bit in case Martin visits here soon: I will >>> compare two approaches 1) reply value, 2) bpf kfunc and then see which >>> way is better. >> >> I have already explained in details why the 1) reply value from the bpf prog >> won't work. Please go back to that reply which has the context. > > Yes, of course I saw this, but I said I need to implement and dig more > into this on my own. One of my replies includes a little code snippet > regarding reply value approach. I didn't expect you to misunderstand > that I would choose reply value, so I rephrase it like above :) I did see the code snippet which is incomplete, so I have to guess. afaik, it is not going to work. I was hoping to save some time without detouring to the reply-value path in case my earlier message was missed. I will stay quiet and wait for v9 first then to avoid extending this long thread further.