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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 54261C433EF for ; Wed, 23 Mar 2022 17:22:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238896AbiCWRXm (ORCPT ); Wed, 23 Mar 2022 13:23:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42360 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343507AbiCWRXl (ORCPT ); Wed, 23 Mar 2022 13:23:41 -0400 Received: from mail-pj1-x102e.google.com (mail-pj1-x102e.google.com [IPv6:2607:f8b0:4864:20::102e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A8A4A7CB22 for ; Wed, 23 Mar 2022 10:22:11 -0700 (PDT) Received: by mail-pj1-x102e.google.com with SMTP id mp6-20020a17090b190600b001c6841b8a52so7040524pjb.5 for ; Wed, 23 Mar 2022 10:22:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:subject:from:to:date:user-agent:mime-version :content-transfer-encoding; bh=Vcs/ijmM+IYtFvRxEnf7jKzIhxJi8SzEvbU3lDOat44=; b=kYrI/ns4ocHbwGR8sPCY3GF2uKSRUMIDNXZHiv2x2s8Ir/8A+gi/C+zdSgtFYvnMme i5FXhdwsyX7uPG2544bS34TPM7fNzf0fW9vefEk3Dyrz6bHVqzeVwUZqWfIKtYde5+7U 1bE7cb4skl6axuKP5JcvkmeA6N7UDLQk3P3jmYE9wJZd6NoI42oMUcyzvnqAytqSQbhZ GuKyXOsWqjgSkbxX9rio3XMKobBcvdCwFIzblWHjWkiy1idcoEi4jWuD9nv+u96hiMXE cGOZpLqO63k1LOxstYqr4letaqEZbOt+cJwWHrkMWv7FBCqBY7onPXyWtSyXdSq4NT/z 03cg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:subject:from:to:date:user-agent :mime-version:content-transfer-encoding; bh=Vcs/ijmM+IYtFvRxEnf7jKzIhxJi8SzEvbU3lDOat44=; b=61rz9oBZBxD056pOIXbghFIZhCHtXGo+54xuWN5wqGdHMdk3K6Rlzi/XUBovmAgWz2 8h9mS8rXuhyKEOwdtiyPzHcP/iROU5wHqboIWcZuxxdDgnGgGVqW1yNooQXZAA875suc JSvBmOgKZ6GPLHL1tK6ZLiH6ynoP0nTX2R7/CjxVOAaPrwlunn49QWP61yy8TaWUCle9 10NP4qq4f1+nWbFNIFCDGbDWahMiME3HMXF1IRxH7n3YoWxXNHDjBxwy7iZaaIMXZpRn 4x6jClcNYPh/3SE0JLHmjFcJmE/YwpgGSmJllNRrBmLOyyDpupzRpAQIZ1XzvkLfxmC3 3gYA== X-Gm-Message-State: AOAM530/UVFUdooVpURg59cZ6by/n717mCZ9WRmYTWQp4N2exypONtOr k0uQvo/AWwZacCbCuvfOd1STtqLS3Wo= X-Google-Smtp-Source: ABdhPJwryMq2E6OAnaqTO7P633o5ddWO8oqxNj7Q9x953gTYMt6utoMde7rZ6FieAekESoDF+101rA== X-Received: by 2002:a17:90b:38cf:b0:1bf:42ee:6fa with SMTP id nn15-20020a17090b38cf00b001bf42ee06famr12887365pjb.9.1648056130662; Wed, 23 Mar 2022 10:22:10 -0700 (PDT) Received: from [192.168.254.55] ([50.45.187.22]) by smtp.gmail.com with ESMTPSA id l23-20020a17090a071700b001c67a95e7fbsm288522pjl.47.2022.03.23.10.22.09 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Mar 2022 10:22:10 -0700 (PDT) Message-ID: <928be46d97a3da3fd677c9d87f9be6a02f4d3277.camel@gmail.com> Subject: poor beacon/scan reliability with mac80211_hwsim From: James Prestwood To: "linux-wireless@vger.kernel.org" Date: Wed, 23 Mar 2022 10:22:09 -0700 Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.40.4 (3.40.4-3.fc34) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Hi, We use mac80211_hwsim and our own 'hwsim' daemon to test conditions like poor signal strength or dropped frames. For quite a while we've noticed very poor reliability related to scanning when HWSIM_CMD_REGISTER is used to process frames. Scan results are just empty. We've put in some work arounds like only registering for tests that absolutely need it and repeatedly scanning until the expected network is found, but there are cases where this is not possible. I'm hoping for some ideas on how to actually fix this problem rather than continue trying to come up with workarounds. I have tried removing any frame processing (just an empty function) and noticed the problem still occurs, basically just calling HWSIM_CMD_REGISTER causes these problems. I will admit this seems to happen more on slower systems, like inside a virtual machine environment, or in tests which create more than just a few radios (like ~5-6+) so it does seem like mac80211_hwsim/wmediumd processing the frame is just taking too long for beacons. Thanks, James