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 EF1F6175A81; Tue, 21 Jul 2026 23:00:54 +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=1784674856; cv=none; b=gLrSZUlpB4iDQ5A5BwN118vGJx3PrcXQA2BHM6Pb862IkOHdW6TUrN1LmesFK24X+i3zWGYli0NLL1ACEHj687+ZKZ2JuQ0TWMuEPB3oipF5xOQdBcsf9gK2dEilHQJJ0FNN1dz5qa6lH1f8CTfMwvX4BtgSAd0i8Xmp4E3kvoQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784674856; c=relaxed/simple; bh=gwZ5a2Fv7e8npqs1QD2Mkdb0zRmX1h0DjmYk7hPcFs8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gs4wz0erkfpxK69WSMUUzayXyUZ9qSWkYytNsJe3z7GFCm7gHclMf+NAfsuDe3snV7sj7TsFhWMxLLtl9Os1kTZK/dPv9uIG/QW1OQ1KfYS4VLXc2DuRPkfTQBGarbhjs6f9xuHOd/jLkuM5YxK7F1TvZmlgnSgg0foU/1n2Ad0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=wNgr2oal; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="wNgr2oal" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FE971F000E9; Tue, 21 Jul 2026 23:00:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784674854; bh=fPpAkRsPCw+pOxLySoSOPYoLKdkpPfSHWm4QWNmeXBA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=wNgr2oalkko04cppbviPZIpHZ4RwEgbN4EYVzI9hvuDxqvtkxKeGfrzTvSD2Y1pFA 3By191b5ntEKPB5kgkdkLsLLHs/1kCxnaxVfU3KNl5x6FT8oHgj9xV5kI3qWq85wiV t0+DCzrzKbNjggz1DdfmwH/LJxCWi9qaf1tVimK0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Taehee Yoo , Cong Wang , David Ahern , "David S. Miller" Subject: [PATCH 5.10 698/699] ipv6: mcast: remove one synchronize_net() barrier in ipv6_mc_down() Date: Tue, 21 Jul 2026 17:27:37 +0200 Message-ID: <20260721152411.527822520@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152355.667394603@linuxfoundation.org> References: <20260721152355.667394603@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit 17ef8efc00b34918b966388b2af0993811895a8c upstream. As discussed in the past (commit 2d3916f31891 ("ipv6: fix skb drops in igmp6_event_query() and igmp6_event_report()")) I think the synchronize_net() call in ipv6_mc_down() is not needed. Under load, synchronize_net() can last between 200 usec and 5 ms. KASAN seems to agree as well. Fixes: f185de28d9ae ("mld: add new workqueues for process mld events") Signed-off-by: Eric Dumazet Cc: Taehee Yoo Cc: Cong Wang Cc: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/mcast.c | 1 - 1 file changed, 1 deletion(-) --- a/net/ipv6/mcast.c +++ b/net/ipv6/mcast.c @@ -2751,7 +2751,6 @@ void ipv6_mc_down(struct inet6_dev *idev /* Should stop work after group drop. or we will * start work again in mld_ifc_event() */ - synchronize_net(); mld_query_stop_work(idev); mld_report_stop_work(idev);