From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 F228C361959 for ; Thu, 27 Aug 2026 20:08:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787861302; cv=none; b=l2gqqFGob0yevwqf2Fy3gbMkuZtOUCZ0X92I34iNqUZZsq/xJJjMaMpM0iDT8zXyU5H11WfrjaAL/TivjzmuJIGbPeQGwkrFzAjD1UNFFFMICe9K6meBxl5ER0eQwFj3hEo7MtZIx7Ob+GMH44tYMqUA/8R1snGQ6atBw5C0yV0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787861302; c=relaxed/simple; bh=eJWWkcQn6zFex8g4tzDJdYLweQBEUlGkwYFJdCKqkVo=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=vAXLkBoM+SOalDbLSHPvrmHBu184YlItJ4wiY1BOWcaurtJuNWlATErY3Hummxsio4jiBUVyJuv57m4j/LA+lNW0r0Ka98ez+FP8ArlxShn9U1ytBFfXItEOkzhbi4MdlTCOMVNntDkv1fEZjojJRfqt3X52ehcw7NsAOK9EjLo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Zw1r1K1i; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Zw1r1K1i" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16EBA1F000E9; Thu, 27 Aug 2026 20:08:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787861300; bh=vIMYHFhVZS8xU7+9c6NV9j1AcxuVR7wd7Zas9PEvl6w=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=Zw1r1K1itZ6J8I8u4euZZtr7Ogtaqfxx2tTwQ4878Ql4Qtv97dQo0QKvixMJ0KHYQ Dync8Bt9Fs4enZrxDX1rUcs7orMCna8n9YJblo3deHLVlLykD80eRgnR/JjxzobG96 Cx545viptUCJMB0VYqoO6HT7zzEGjtAA1RgP9x3tIaYDd0UFaqrrlHMHl7g0XmOd3q YaKUX8xwSaAamnVqLbdTU2EIbs6DCBmFyscQ+gHOGMkXz/jjCBPYvUeC6BfWkfS146 Zm+v4DFnD22AoMW5U/uDzFs23yuHcAyarMFoQ6NSuO664TL1CeMsu9QjJLFZ1VP6sJ S9R2FxHDUoedw== Date: Thu, 27 Aug 2026 13:08:19 -0700 From: Jakub Kicinski To: Eric Dumazet Cc: davem@davemloft.net, pabeni@redhat.com, horms@kernel.org, idosch@nvidia.com, dsahern@kernel.org, netdev@vger.kernel.org, eric.dumazet@gmail.com Subject: Re: [PATCH net 3/5] ipv6: mcast: fix delay calculation in igmp6_join_group() Message-ID: <20260827130819.293763e1@kernel.org> In-Reply-To: References: <20260826103711.3302915-4-edumazet@google.com> <20260827194259.4022994-1-kuba@kernel.org> 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 Thu, 27 Aug 2026 22:02:27 +0200 Eric Dumazet wrote: > > So for case 1, is the actual symptom that the randomized delay is lost and > > the second unsolicited report goes out on the next tick, right behind the > > first one, rather than a report deferred for weeks or months? The stated > > symptom implies dropped membership reports and multicast traffic loss, which > > reads differently for anyone triaging this for stable. > > > > Case 2 (a delay inherited from a query with a large maximum response delay > > exceeding unsolicited_report_interval()) matches the code, and the clamp > > added here covers both cases either way. Could the first paragraph be > > reworded to describe the lost randomization and the reuse of the stale > > expiry instead? > > OK I can rephrase the changelog to: > > 1. If the timer has already expired (timer.expires <= jiffies), the > stale expiry is reused by mod_delayed_work(), causing the second > unsolicited report to fire on the very next tick without a > randomized delay. > > 2. If the timer was originally armed by a query with a large maximum > response delay, delay could exceed unsolicited_report_interval(ma->idev). > > > Hopefully, all the AI agents will be happy this time. Feel free to ignore, I hit send because of the complaint on patch 2. I may have misunderstood but I read that one as "delete requires optmem headroom".