From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BF61DC369D3 for ; Mon, 28 Apr 2025 06:50:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Ha2q7ENjcOol2cZ6J28FpewXXQPD2/ri+PDV0U8UBac=; b=cartLAja2LjeYDaaN6RHtaafU8 JbYv4oanjnxgYE99965x56rsieBfgQ/RLmp0D0KX6YSU1jzMPGSfxXGQ7aWllzYr4b/qKfZnNYLvx wKBu+dtHHYwWMVP7fDckOfRfBr0YN64EBI/APQJgmOkHw1zV3Xj5JJFH/jELpQ3oB/pAxjwWoFvAZ ir/VwSKlwJ2CK8Sfs0zAFJg/liyguN8TVvi2sXjhakGjPPZ4R+vAA6UqmofA1aqlf3bKOkVahM/75 /nL/XsT4aZ9LWLiPX9bVW4ReUfTD+mmTou7sS9MW7zwDYsYe+FUZEdDaUkK0y1h4nty5HA/jA8mQ0 U2OnlI8Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u9IKQ-000000059MN-191E; Mon, 28 Apr 2025 06:50:58 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1u9IKP-000000059LS-0zTP for linux-nvme@lists.infradead.org; Mon, 28 Apr 2025 06:50:57 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 0E88561156; Mon, 28 Apr 2025 06:50:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C32D0C4CEEC; Mon, 28 Apr 2025 06:50:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745823056; bh=vDp9/WG8RyahFUQFSOVnfzGiMm8bLCgzRkeyEZE47BM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UFvtSbcklqI0OvQTuwQubhBcx9bLbiOTXIr4hXI+++nDK7btMQAlB1yWPilnbHcwB fkRkKQtNurxJrfMY3/Gl5vpnOYHWrzmoqEZclhFPkXBEqx0gjq7rwHhhZymMpKI9wi 9Lt0d786dWH70KYQzVXGT2j4JzqEsJpsnxroQlv4umw3M0IssTox/98iZMZoCIN73l NQrJfXPbDDFIMu4JYBUr1YeVjcOUyyjwE9MeWcNV9gX10h2zIAL7XI4309IWjN66Z/ nHWIJFOPvbRqxGfMQkPnsxRH5taxNbRwpnrLclbYHJlm3t/wzzVytocT2ehVFz50/I T4aqkb0hYLONA== From: Hannes Reinecke To: Christoph Hellwig Cc: Keith Busch , Sagi Grimberg , linux-nvme@lists.infradead.org, Kamaljit Singh , Hannes Reinecke , Chris Leech Subject: [PATCH 2/2] nvme-tcp: fix I/O stalls on congested sockets Date: Mon, 28 Apr 2025 08:50:40 +0200 Message-Id: <20250428065040.32663-3-hare@kernel.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20250428065040.32663-1-hare@kernel.org> References: <20250428065040.32663-1-hare@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org When the socket is busy processing nvme_tcp_try_recv() might return -EAGAIN, but this doesn't automatically imply that the sending side is blocked, too. So check if there are pending requests once nvme_tcp_try_recv() returns -EAGAIN and continue with the sending loop to avoid I/O stalls. Acked-by: Chris Leech Signed-off-by: Hannes Reinecke --- drivers/nvme/host/tcp.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 10ccd7cf5b8c..5c73af022273 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -1363,7 +1363,7 @@ static int nvme_tcp_try_recv(struct nvme_tcp_queue *queue) queue->nr_cqe = 0; consumed = sock->ops->read_sock(sk, &rd_desc, nvme_tcp_recv_skb); release_sock(sk); - return consumed; + return consumed == -EAGAIN ? 0 : consumed; } static void nvme_tcp_io_work(struct work_struct *w) @@ -1391,6 +1391,11 @@ static void nvme_tcp_io_work(struct work_struct *w) else if (unlikely(result < 0)) return; + /* did we get some space after spending time in recv? */ + if (nvme_tcp_queue_has_pending(queue) && + sk_stream_is_writeable(queue->sock->sk)) + pending = true; + if (!pending || !queue->rd_enabled) return; -- 2.35.3