From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B8C3E2DEA8C for ; Sat, 14 Mar 2026 16:06:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773504375; cv=none; b=gCF2Shdle0/TBdt41QzPlE8RuGQCROg58FvWoH5qfvVKYpYeVgJ3jT67EAtuDoQKsnb5zPUqVgYoMdUJOqIAuCcorJ+eGLGKMgWfrHIRaGJm0Sp6ueHlO+Dp1Ggo9iIjVLFYQPGIhWMBbMq6xkOQPIKYjVxXNPUKDlS71BY9ex8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773504375; c=relaxed/simple; bh=5iT9f/SQfYrkwdPGbepNnEtTWPIA6guAy88FhJub868=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ewHZq6FSmw6ytrDomTmMho7xH0wme+VYw6r5YXfkj00j98OzuSPfvQ3rUqORa0uxtAOARHp1tmSf6cYFanB6E1Zmmcxnuifclq3wcgLZ6aza5w8zd023rwxvBvD+0HbtnR2muyVhYeNKAcB2Yg12C2eLTz7/mAVh+AC6fiacmps= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HdllJmcA; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HdllJmcA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F0EDBC116C6; Sat, 14 Mar 2026 16:06:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773504375; bh=5iT9f/SQfYrkwdPGbepNnEtTWPIA6guAy88FhJub868=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=HdllJmcARJv8aPShIldh6My2Qwkimi8CpUEeJK1N/jka0+PG2H9XjFyWgVbTmFzMu c7jU1dMTmg4KJB1sTovyRPl0ByUSgNh8T0B26BUXU+bHFE/4PFfJ/7++KaUE7LSviU 8dzYQvVQKm54QOunglS+CzlI6bF7CUCR8QSjuSHtUtleuNz/dSqaKVhVVc//ljQzUZ 6I7GNIpJ9xE042EpvPBCK3hMRLJ/2DgyZlnWh9CKP6gVNqUNEwJiNgpzN/Sjsmf6DP Km0/Ec620rMMqYF/CsCHy9g1xm2cq7hFE8OoYkDxlLY8qrXpsTCavUQdSRmaOay3vV O/00MzlHej4sQ== Date: Sat, 14 Mar 2026 09:06:14 -0700 From: Jakub Kicinski To: Fernando Fernandez Mancera Cc: David Ahern , netdev@vger.kernel.org, tgraf@infradead.org, horms@kernel.org, pabeni@redhat.com, edumazet@google.com, davem@davemloft.net Subject: Re: [PATCH net v4] ipv4: bump rt_genid when a relevant devconf value changes through netlink Message-ID: <20260314090614.116f38cc@kernel.org> In-Reply-To: <633f5de1-daeb-48ac-aba1-92b3c3ccf5c8@suse.de> References: <20260313144555.4956-1-fmancera@suse.de> <1644761b-4960-431f-bf3d-5593007212fc@kernel.org> <633f5de1-daeb-48ac-aba1-92b3c3ccf5c8@suse.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Fri, 13 Mar 2026 16:13:20 +0100 Fernando Fernandez Mancera wrote: > > Also, you are flushing the cache for more values than sysfs does. > > I don't think so. The problem is that the handling of sysctl is > scattered in several places. > > IPV4_DEVCONF_FORWARDING is flushed at devinet_sysctl_forward(). > > IPV4_DEVCONF_NOXFRM, IPV4_DEVCONF_NOPOLICY, > IPV4_DEVCONF_PROMOTE_SECONDARIES, IPV4_DEVCONF_ROUTE_LOCALNET, and > IPV4_DEVCONF_DROP_UNICAST_IN_L2_MULTICAST are flushed at > ipv4_doint_and_flush() used by macro DEVINET_SYSCTL_FLUSHING_ENTRY. > > Finally, IPV4_DEVCONF_BC_FORWARDING and IPV4_DEVCONF_ACCEPT_LOCAL are > flushed at devinet_conf_proc(). > > Yes, I know, the fact that they are scattered around is quite confusing. > This could be all unified in a single place but that would be too much > for net tree IMHO. > > Please let me know if I am missing something. I think David means that for some knobs procfs only flushes when value changes "in one direct", eg if (i == IPV4_DEVCONF_ACCEPT_LOCAL - 1 || i == IPV4_DEVCONF_ROUTE_LOCALNET - 1) if ((new_value == 0) && (old_value != 0)) rt_cache_flush(net); which means only flush on the 1 -> 0 transition.