From nobody Wed Oct 15 22:41:25 2025 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 B2F4C276C52; Sun, 24 Mar 2024 23:36:35 +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=1711323395; cv=none; b=OddUsV1bHiJvVTXwkHUSQxRmJRMeaEIXXDNUc+09J4ksZfLg+ZPpHcJoRwFb26NS7KUMD9xIQ4zjJ4qhfAq1x/GYDhy7c5YL2/2G+yFMIo5vTLLzaxVBD8EV4zw05hBEnuVi1uftIDV+2q5DQQwh7As8VOQmPvZkOPldRJdBTaQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711323395; c=relaxed/simple; bh=zWlzrrm/5wQhSozp+1bHo/83+epwrXZElVWrst8o21k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cQnh+YOgMH6ec0Lx9PI7mc3c0O8mVppaO/5rQfjXjHpQAHXsg0rolXdZMEZrScycdl0E6TP8jpVGg5d4S3fIEtBX1SNI3LFb8PQFwxoZ0YzuRX3hJ4WNkykwRQ+rvxHPEYtgSRO0wpZqkDvFcGrMG4/sTOu0yZjqG2Y9RzkJ3hM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=d6D15jeP; 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="d6D15jeP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3A98C433F1; Sun, 24 Mar 2024 23:36:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711323395; bh=zWlzrrm/5wQhSozp+1bHo/83+epwrXZElVWrst8o21k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d6D15jePQjHcjKyHOqEK9QdipMOL0uYc8UBeHY6GACXglxvJv02XDephX7eZ7yfyD FMX2tQqbGVm90Q3XUWfBSCpG6z+1/KwZg+eiH8Jum09x3lfaLaZIfHixA3W/xqzVD2 3KgMceYiiS2s0eEqqAoROM6vWAwDln58lu4lV1XropV+VhFulFg/rDItxVegqHmjVb gQhmNkUp3OFhCwus8HL0mxcjo4kg78LHymXOMMHrXkRXhFtlQ+LnjTIoJnEeocEQGE ISitSVrME6zS+SDbZA/jz+xSZBouT5hvBEVHcDVD/9VAvt0tVWp5dWLJTHemc3V2Mi tQE4aaxmp+95g== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Dumazet , Taehee Yoo , Cong Wang , David Ahern , "David S . Miller" , Sasha Levin Subject: [PATCH 5.15 096/317] ipv6: mcast: remove one synchronize_net() barrier in ipv6_mc_down() Date: Sun, 24 Mar 2024 19:31:16 -0400 Message-ID: <20240324233458.1352854-97-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324233458.1352854-1-sashal@kernel.org> References: <20240324233458.1352854-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Eric Dumazet [ Upstream commit 17ef8efc00b34918b966388b2af0993811895a8c ] 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: Sasha Levin --- net/ipv6/mcast.c | 1 - 1 file changed, 1 deletion(-) diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c index 0ea7d97cdc025..6e5d1ade48a89 100644 --- a/net/ipv6/mcast.c +++ b/net/ipv6/mcast.c @@ -2722,7 +2722,6 @@ 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); =20 --=20 2.43.0