From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 339973C062C for ; Thu, 7 May 2026 14:34:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778164455; cv=none; b=oGH2qazyD/6ENM9a2u5KaJlhO/27zKa/FGYwZicmLJnwtGi4TF5QaQ3Pg2IqzAEeCkmZEz49W6hH/BzKhY0JXLlSu60uvopHhCjMM8nMxUl/5+T1j+5HUB4GrE6Zy91raRvbCiF7+YutlqYqrygxuKpd0g2yJJf6lLnnFm9qI44= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778164455; c=relaxed/simple; bh=REMXR87aQf+FeEBUtnHfLNXYS9O6phyTNdtm6aANwSk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=IfAGt87VI2Gq14Pp8Ze69qZC8V/dACY7oY9aTyPQCzKjHSTiBCWqdi81E/nDrqfctGf+jhLlxzVdYtoQrY8WJUr9KvKmBQTmN59gtyWZVcmSN8+kW0qeI2RDdUHuR1zUD6AKSu6TDHxPiZgPnC10rrkke0QGCMcsOUD7kKznkII= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=AstMe03e; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=eahzJnwx; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AstMe03e"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="eahzJnwx" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1778164453; 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=YfqPv4kAzqZ0NRYAwjXSQgvfmomJWQGhAYSphsjCSpg=; b=AstMe03e8JTl0GFguTD/Xms+rIswXvyoYbDTvuN+q2esLDWTVmovbKPz7aEz0gku3T7PNe yWm55irlT2Aq41mrOQ42Tbc7F7/4H+SIIAPvi72Pk52UcP5OJ6YIRZouKlGRPGvPTDsydr +r0GIzS9fxiH8wcWXtF8DrTvQSnFEuI= Received: from mail-lf1-f69.google.com (mail-lf1-f69.google.com [209.85.167.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-88-e08v1sBZPRWpBCd3ozaNFQ-1; Thu, 07 May 2026 10:34:11 -0400 X-MC-Unique: e08v1sBZPRWpBCd3ozaNFQ-1 X-Mimecast-MFC-AGG-ID: e08v1sBZPRWpBCd3ozaNFQ_1778164450 Received: by mail-lf1-f69.google.com with SMTP id 2adb3069b0e04-5a7437b4ff9so1127656e87.0 for ; Thu, 07 May 2026 07:34:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1778164450; x=1778769250; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=YfqPv4kAzqZ0NRYAwjXSQgvfmomJWQGhAYSphsjCSpg=; b=eahzJnwx6U4GSR2lErHWzM8JmrbIvVRjds9r6QBA3nzOUZrSouWzsZpK4kloZYmZMq jOVIwJFCtL97QF0JrBtuoKX/sQX114lHAfSo5dYPcwZkQZOfETAZ9BWTf408KhV2goKJ 7YJ6Y0l9TwLpFUtkX8YgwHeQlbJ7c21R8LI6WPH5StR2VJ0jJUBRGyiRDv9gTdjxGVYU +PUEa5SAqgpE+FzUADOOmapWbg/3QAdraaLIHeVwzuG4oaincaAFS4EijG67LIeAHJbw xTs8nbhVn7yzepeqmj8oUdGZsp6Ev+J4i/evi2IYR1fuAE0DEOFjjmymTi3TUxE6COj8 NerQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778164450; x=1778769250; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=YfqPv4kAzqZ0NRYAwjXSQgvfmomJWQGhAYSphsjCSpg=; b=J3wOiyawW40RFJH4rHcy1d+8QKfjlpJK+RAuCnZIIGh1Izm4UcHIpbaM4UOc8qdzea MRmu5o6EtCMHTi7ok8geNXr6Sk06QPkV91KJH4mcsa2Ue0F1AbQZEWMdtcacaRvot14Y EnhrUQsrZ/PWk/PSlU0vP4tun4eHWadXEmTfN3xVI+fVCxl+Rof+96rbEJDF40j5ka4n AFJ1LBzJRvhqBc/vgBlfszi1FcunXwBzGpUCpfM4GNVAk3M/jLCSuOxFsBa7m06Qw3FO WuMKg0vwHVcF88JtAdmdhftnrRaDvSex8BG+bh335J0NIWYwDvoep4G/LWBFO+c1S7W7 qRRg== X-Forwarded-Encrypted: i=1; AFNElJ9eb6SqwqDhgg5Bgy08K13IHQs40sO9wHmaWnljHLyOkLU/uSy2eVu4jKWg/5SKkjXdyhvyXDk=@vger.kernel.org X-Gm-Message-State: AOJu0YxF49xpQuprZtJvYuf0lJwP7A++Gba3bfl5/bc89ffudBDN6rpg QyvMAciflsMtruV8EPBlGq2XZJCZBincwsH2NZ1U3aMGggVsz/7U05ZCPqE57S1eCFFmqJpqiQE wQYkiJFhqYHBPK+8QU8LKjgFHsSCVYqV30jbAo2n/hjrsfPHSeNOzCrJbNQ== X-Gm-Gg: AeBDiet+9x+Mh8uPS+Bla8qITW3lka4O8zlmKBP8XO7wEKNadx9OC6L+BvqH6jTeqH7 Ay00mhXrDgUPh0F4Q7yzullrkDY6ujbZRs4hUWjOrMBEhqJh3GyDd9SYVqXQ7C4X/2RdXmMYazj SA94AQLRaMZiutXjOUlhSZt2fSUU6zMtSxaOtBVJo7p1p8d98wGmEPA823m6oNAVDyOt0pK0tqN Ku5vnbizO6rfyI8MF7h0kAgM9LSedJzhGELG8jFiuiu/AkYWDQahkGFoZgi1KYkQf11kccIBVzq tJUYnrGXZEiyDJZqYTKNRsLpDW4cALktsr4dVvWK58Fq0iNCyq0zybVEyRBm2l9lD0UujpfsCYT moDRAzyB7YepRqFThiZ/7QSrJsZbmfxrFdudqPD8DNv0IZlY2tTjduZXE2Dve8LEv0g== X-Received: by 2002:a05:6512:124a:b0:5a8:5eda:a0c9 with SMTP id 2adb3069b0e04-5a899bcd989mr1036584e87.18.1778164450070; Thu, 07 May 2026 07:34:10 -0700 (PDT) X-Received: by 2002:a05:6512:124a:b0:5a8:5eda:a0c9 with SMTP id 2adb3069b0e04-5a899bcd989mr1036561e87.18.1778164449286; Thu, 07 May 2026 07:34:09 -0700 (PDT) Received: from [192.168.88.32] ([150.228.93.82]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-5a886d248a5sm1671466e87.56.2026.05.07.07.34.07 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 07 May 2026 07:34:08 -0700 (PDT) Message-ID: <8f2f7f2e-6aa2-4e5b-b52d-0025b2525579@redhat.com> Date: Thu, 7 May 2026 16:34:06 +0200 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net-next v5 3/5] veth: implement Byte Queue Limits (BQL) for latency reduction To: Simon Schippers , hawk@kernel.org, netdev@vger.kernel.org Cc: kernel-team@cloudflare.com, Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Alexei Starovoitov , Daniel Borkmann , John Fastabend , Stanislav Fomichev , linux-kernel@vger.kernel.org, bpf@vger.kernel.org References: <20260505132159.241305-1-hawk@kernel.org> <20260505132159.241305-4-hawk@kernel.org> Content-Language: en-US From: Paolo Abeni In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 5/7/26 8:54 AM, Simon Schippers wrote: > On 5/5/26 15:21, hawk@kernel.org wrote: >> @@ -928,9 +968,13 @@ static int veth_xdp_rcv(struct veth_rq *rq, int budget, >> } >> } else { >> /* ndo_start_xmit */ >> - struct sk_buff *skb = ptr; >> + bool bql_charged = veth_ptr_is_bql(ptr); >> + struct sk_buff *skb = veth_ptr_to_skb(ptr); >> >> stats->xdp_bytes += skb->len; >> + if (peer_txq && bql_charged) >> + netdev_tx_completed_queue(peer_txq, 1, VETH_BQL_UNIT); > > In the discussion with Jonas [1], I left a comment explaining why I think > this doesn’t work. > > I still think first that adding an option to modify the hard-coded > VETH_RING_SIZE is the way to go. > > Thanks! > > [1] Link: https://lore.kernel.org/netdev/e8cdba04-aa9a-45c6-9807-8274b62920df@tu-dortmund.de/ In the above discussion a 20% regression is reported, which IMHO can't be ignored. Still the tput figures in the data are extremely low, something is possibly off?!? I would expect a few Mpps with pktgen on top of veth, while the reported data is ~20-30Kpps. /P