From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sipsolutions.net (s3.sipsolutions.net [168.119.38.16]) (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 C8A18423A66; Thu, 8 Oct 2026 07:44:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=168.119.38.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791445497; cv=none; b=C9C0Wm8kM5FSa5bvMyqk4FmPavq1wHnu2f4ZQJ0HcbQR92d0SvjtJ3NXR7tNg5cnZPqySvdBSgvpg76Gjv9rZsnuyjPKYwtZVDyn+VLKeeYuwxSP2i+XPyiARrQnoVrYnu/dzCubNM8pHe7A9Aa5s63Jux9ZcM3HbjRyDN87EHw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791445497; c=relaxed/simple; bh=SX8aHBZ+Jvm6rjNABPl//Et/ydQ+AprwhtNg3ayxDFM=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=tDBkODA0fCy6FxLf5uZwAJbyPYa4tTdtKbCe2Ti2Os5byHH860BnlUeXAnL5vyc4PpwNO61sdjNi8vP/Aw0L21fcC0MBCGm8xNTOS0s6lchub/iMhleWUkfIiENxd8PfHhdeDCp5Tz2MPxCVQLI7er5kuHA85qlgl+EfAG0WS2U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=permerror header.from=sipsolutions.net; spf=pass smtp.mailfrom=sipsolutions.net; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b=fTtjHnj7; arc=none smtp.client-ip=168.119.38.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=permerror header.from=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b="fTtjHnj7" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=RAFFMHXt9hKqc6DeNIeiFUmCqfwK92D95q9EzUKD8ns=; t=1791445493; x=1792655093; b=fTtjHnj7tRQ1b//azj+cLa6f6XdxR3GAw/FmIcOSuy+GQc7 sMthauipDJswEjzTLacGpw7bUzd+3wdbJMTx9RAsBQKh1rRWmMDXh2Cpv6fwzWjtQfoi03H5JQg5a HWJmWYOwRNN++coZeAdFzHQ+Pbajk8GD9uCYACFgDZiazi0VKz9Mpfv2lr8lAkQvt5inJlHv4ZL71 jPB03jllmlP5VMXiNpVB0OBbHTFB2igCDt6CuXQKNCBWnTaJt2w62lG3rixa0ikPNjWwAK7bVy992 39UuvnPxYLoTvV8011VEO1h3K15nrhZ1sMwgd/XO7fVC7QtCe+Rch47nO3kJ4BSA==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__ECDSA_SECP256R1_SHA256__AES_256_GCM:256) (Exim 4.98.2) (envelope-from ) id 1xEio6-000000099KQ-11jF; Thu, 08 Oct 2026 09:44:50 +0200 Message-ID: <2688563455012eb80063ae014f78230b10a14710.camel@sipsolutions.net> Subject: Re: [GIT PULL] wireless-next-2026-10-07 From: Johannes Berg To: Kuniyuki Iwashima , Jakub Kicinski Cc: netdev@vger.kernel.org, linux-wireless@vger.kernel.org Date: Thu, 08 Oct 2026 09:44:49 +0200 In-Reply-To: (sfid-20261008_040528_485050_028310B5) References: <20261007205827.467974-3-johannes@sipsolutions.net> <20261007163616.1088d364@kernel.org> (sfid-20261008_040528_485050_028310B5) Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.60.2 (3.60.2-2.fc44) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-malware-bazaar: not-scanned Hi Kuniyuki, On Wed, 2026-10-07 at 19:05 -0700, Kuniyuki Iwashima wrote: > On Wed, Oct 7, 2026 at 4:36=E2=80=AFPM Jakub Kicinski w= rote: > >=20 > > On Wed, 7 Oct 2026 22:57:00 +0200 Johannes Berg wrote: > > > Nothing much going on in wireless-next. However, next time > > > I hope to land my RTNL-redux series which will (almost) > > > completely wean the wireless stack off the RTNL, except in > > > places where we need it for netdev register/unregister/etc. >=20 > That's great ! >=20 > We saw a wifi driver holding RTNL long on Android. Well, _that_ mostly shouldn't have happened for a long time (since 5.12), though I actually learned yesterday that some android drivers went to implement things with private ioctls because they (thought they) needed the RTNL ... so, Android, take with a bag of salt. > Also, I hope we could remove the long comment in __rtnl_unlock(). Couldn't we remove that today, by just __rtnl_unlock() in that place in cfg80211? But it's not exported, for good reason, presumably. But that's also irrelevant, because indeed after my patchset cfg80211 doesn't do that any more: https://lore.kernel.org/linux-wireless/20261006100655.2687533-21-johannes@s= ipsolutions.net/ > > > I need to see what's going on with the per-netns mutex now, > > > can we already use that instead? >=20 > Do you mean moving net->rtnl_mutex out of Kconfig ? I have no idea what I'm talking about ;-) > Recently, I've been converting the first-class rtnetlink handlers > with dedicated locks, but others not worth the effort will simply > replace rtnl_lock() with rtnl_net_lock(). >=20 > rtnl_net_lock() still acquires rtnl_lock(), but if we always compile > net->rtnl_mutex, using __rtnl_net_lock() for the latter should be > okay. OK so I (likely naively) thought the idea was that most things like netdev registration/unregistration eventually move to rtnl_net_lock()? Here are the places that still take RTNL in wifi after the patchset above: - suspend/resume (not entirely sure - it goes to hw restart maybe) - hw restart (can unregister netdevs on failures) - rate control init in mac80211 (but that can be removed easily) - netdev registration - netdev unregistration - rfkill, to call dev_close() - wiphy registration/unregistration (might be possible to disentangle now) - network namespace destruction/exit - wiphy naming, but that can move to cfg80211_mtx now - some netlink dumps (related to the naming?) - testmode/vendor ... I guess we can't get rid of that, but no upstream drivers should have much here - interface/wdev start/stop - netns moves (and a couple of places I should just fix). So mostly that's relatively short-lived (like the wiphy naming stuff) or related to network/netns maintenance where I'm not sure. Thanks! johannes >=20 >=20 > >=20 > > That's a Kuniyuki question (cced). I've been trying to move > > HW drivers out of rtnl_lock and under netdev->lock. > > Most of the rtnl_lock contention I've seen in prod at Meta > > is in init_net >=20 > FWIW, I've still seen contention while creating/removing containers.