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 79BEB144D00; Thu, 13 Jun 2024 11:42:00 +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=1718278920; cv=none; b=LYgmYNZ0oCCTFQ4dOHNxrai91ILUjjtw2zCGlHdlGFhrMVanZwq2QW8OJJwcDbEg/2hT+7LE7ABMLfYnS4bkLp1QT17tr6aKnsLHJr2Y4EvRYAk1GyeOiZ3hmoYBITROnRn74j4rZHWdiZmsOz3sJvHjViyaUbORdKsXdlT4V6M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718278920; c=relaxed/simple; bh=FTvsF0rQgUtWC+5UslWo0XTquX8ILB7CaPgyzU3mhww=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NlVhWfDGnaUzjZJzIdgqqXpDFRdxN6/cxJK10e9Gj0R+PfPCzC88XVYTWRVgDptfM4tLFUUkJYR+tMu9fDnrKIY16YQCfobDdiWv+pJby9oUmY1tCR5bxbGCpp1LG1TzIW/rU72PdkHIWvdGFFcxsDZJwaM3P3/ddcSG5aSfuGc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=M90jh+pa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="M90jh+pa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9ED6C2BBFC; Thu, 13 Jun 2024 11:41:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718278920; bh=FTvsF0rQgUtWC+5UslWo0XTquX8ILB7CaPgyzU3mhww=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=M90jh+paZohf/JbMoMTHCzLx6kuq1Po94TMefF8O4Yi/6QqEyrQBBLajfL3t8H812 vjFjTEA+ihorNhUgqeyZIW9qzSJvO8O9GLzgG1Fq9PSjS7foXzaZGRcgxoL6pR9mKm WlByBRJAMGoBAo8HD0h044VYNgjfF5rq/deuGNho= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Neil Horman , Daniel Borkmann , Willem de Bruijn , Jakub Kicinski , Sasha Levin Subject: [PATCH 4.19 084/213] af_packet: do not call packet_read_pending() from tpacket_destruct_skb() Date: Thu, 13 Jun 2024 13:32:12 +0200 Message-ID: <20240613113231.251681513@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240613113227.969123070@linuxfoundation.org> References: <20240613113227.969123070@linuxfoundation.org> User-Agent: quilt/0.67 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 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 581073f626e387d3e7eed55c48c8495584ead7ba ] trafgen performance considerably sank on hosts with many cores after the blamed commit. packet_read_pending() is very expensive, and calling it in af_packet fast path defeats Daniel intent in commit b013840810c2 ("packet: use percpu mmap tx frame pending refcount") tpacket_destruct_skb() makes room for one packet, we can immediately wakeup a producer, no need to completely drain the tx ring. Fixes: 89ed5b519004 ("af_packet: Block execution of tasks waiting for transmit to complete in AF_PACKET") Signed-off-by: Eric Dumazet Cc: Neil Horman Cc: Daniel Borkmann Reviewed-by: Willem de Bruijn Link: https://lore.kernel.org/r/20240515163358.4105915-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/packet/af_packet.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index e8b05769d1c9a..4ddc60c7509fb 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2441,8 +2441,7 @@ static void tpacket_destruct_skb(struct sk_buff *skb) ts = __packet_set_timestamp(po, ph, skb); __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); - if (!packet_read_pending(&po->tx_ring)) - complete(&po->skb_completion); + complete(&po->skb_completion); } sock_wfree(skb); -- 2.43.0