From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5BC84C2D0DB for ; Wed, 29 Jan 2020 18:40:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 335482071E for ; Wed, 29 Jan 2020 18:40:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="H74ENqB1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727512AbgA2SkF (ORCPT ); Wed, 29 Jan 2020 13:40:05 -0500 Received: from mail-qt1-f177.google.com ([209.85.160.177]:33331 "EHLO mail-qt1-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726332AbgA2SkF (ORCPT ); Wed, 29 Jan 2020 13:40:05 -0500 Received: by mail-qt1-f177.google.com with SMTP id d5so319014qto.0 for ; Wed, 29 Jan 2020 10:40:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:subject:from:to:date:mime-version :content-transfer-encoding; bh=edDbto1ayWJTc7kkFco+GN3h20aSoy5f31PU1XYRnl8=; b=H74ENqB1d0MpbPoFJrusHJYZfaAypd+fE6rB6R4o38hbL5OSErOD+DLEjiG5HaLhHW ftHbZMmxPMSbpVEJ8JgrYOjHDP1/Wxq5I4Eemslw8D6FGoSNXDHv9VAHI0kR19Pw2FaF AgBq2QBhwhnUcypvfY49uIkv/vGhQNIbHThXKhfMZNafk0hJ1JbLa5qroTsVj6pD8GTZ kvwOr6WSfH4GTxRELPu7xsu7S9SaDqAC9CB3T6clOOY2BBKxnThGIYCSu/cN1EqSeeCX unE5f7eEVnvOdpvKH9WYonjt93AMo7scAFWvi5y2MQqKnOGkRMNR7cqMNlJwHd5B+qNu 43MQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:date:mime-version :content-transfer-encoding; bh=edDbto1ayWJTc7kkFco+GN3h20aSoy5f31PU1XYRnl8=; b=CcGvWxCuVZSjfHM5up9ZQOLO5QfjKe7fLZlfujohUMsqEaXCaRtr6v7JJ2la4rRbvg +CyygFJ/Ixqw1NszXOoJdT/smv3ZGlIWOP4CwCpRxoQ15hvwR5WRqTnBs9D2LycJWEv5 W/Nc8JZhIQ13xtLCpCkAnYmquWE6OBV/LiesePrzPMuBaQqLX8e2bcYD3/78BHQ81ROz 28mmD6tWXHQaz/UGc2E2yh9IYJwzrrDSIzhMJ5Q5c2E28qMcBXfmuACNNe7LlpfFbm7G Leun7AqpWOiuzzOKXtMxdb7mJ2HAUKFa8ws9i/vxfEjSexjJcS62y0z8sPvtgCKuYpmh l8Vg== X-Gm-Message-State: APjAAAXFCVrhwrsyMBpEgFj7V5undRDkqiKFsUxkc2KTDUqAhvutX5S5 N3vmEQ8AtVjnc1qh6i9++00NUBJE X-Google-Smtp-Source: APXvYqxzurb/DkcwamAbS4cisE08RBAT6nsSE3F9kGcbuai3KusQcJ5CjyLyKOuo+Mcu5e2fKVvz9Q== X-Received: by 2002:ac8:6f04:: with SMTP id g4mr596577qtv.314.1580323203534; Wed, 29 Jan 2020 10:40:03 -0800 (PST) Received: from [192.168.0.10] (dhcp-108-168-58-21.cable.user.start.ca. [108.168.58.21]) by smtp.gmail.com with ESMTPSA id z1sm1433199qtq.69.2020.01.29.10.40.02 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 29 Jan 2020 10:40:02 -0800 (PST) Message-ID: <1580323191.26012.48.camel@gmail.com> Subject: Strange performance issue when using two devices at once From: Marlon Smith To: linux-wireless@vger.kernel.org Date: Wed, 29 Jan 2020 13:39:51 -0500 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.5.2-0ubuntu3.2 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Hi everyone, I have two RT5370 devices connected to the same access point. Both devices are very slow, but the instant I disconnect one device, the other speeds up by a factor of 10. The really strange part is that one device will perform slowly even if the other device is basically idle! I've confirmed this with a packet sniffer. I've been trying to do some debugging, and I've found that when both devices are connected to the access point, they report a large number of duplicate frames. I added some debug output in ieee80211_rx_h_check_dup() to confirm that this only happens while both devices are connected. The packet sniffer also shows a large number of retries while this is occurring. Using backports 5.3-rc4 for this, but also tested on 4.14-rc2. I did post about this previously on this mailing list (RT5370 performance issues), but I thought I'd post again with this new information and more descriptive title. I'm a little bit stuck on this for a while now, so any ideas are much appreciated. Thanks! Marlon