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 9D5E53B6356; Tue, 21 Jul 2026 21:28:55 +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=1784669338; cv=none; b=Et3OWxocCD/prMW0RLvevtIMW1syUfIaRf3lWa/OJw9MVYHQ8Bgr94KQZHZaQZSz0/P0PCiHmiZEMz0qVMOa/YmJMu2Lhz2jdUCMBSOrU+i3jIv0vR0Pi6Olyw9p5DGH0v2HSqsbLoDitPLGz6h/CqjoCSs4TN2CwSU/MO3MCfc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784669338; c=relaxed/simple; bh=yEDj5Q7e9yR6XvDlL562W4U9k4nogUmNvC4M3bpiAr0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aDBuB62Il97oC6BRx7x6Mkdw8wXhScpZogS/jQqglNqJDfePyVjazIVG6jl+W2OOx8UsIijqsM465axecQETEBAosmqM6zn/zyO1pfQ/zY6FzGUWF788+bz5Ve99MpCMaNIdZZwXHt3Ry3b0tPhUNsUA8NFVyzNfDmBfgUVsBdw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=DC0Tt8M9; 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="DC0Tt8M9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4EBF31F000E9; Tue, 21 Jul 2026 21:28:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784669334; bh=f7jmCjR9bEqiMem0GZuUts3xO0LkaqgCuhl+Ohgmi00=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=DC0Tt8M9vx1sRvnKajt6dAQSNW3yLvdNs+hY/4t1vi31tKOVnS4PJmDSvafNjSLjY 81wyPKkEmVoibRW0nWE7WvyfvbUxSmLc26VOKdXyMK9r8/h/ZUjfFbFZ4YnbGNSx08 Xi9UcO8gVDQpE9R9KHvwUzh7DyAfg5ieTubOxNPo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chuck Lever , Trond Myklebust , Sasha Levin Subject: [PATCH 6.1 0514/1067] xprtrdma: Avoid 250 ms delay on backlog wakeup Date: Tue, 21 Jul 2026 17:18:35 +0200 Message-ID: <20260721152436.110760260@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152424.521567757@linuxfoundation.org> References: <20260721152424.521567757@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 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chuck Lever [ Upstream commit 100142093e22b3f7741ac88e94878bb3694e306f ] Commit a721035477fb ("SUNRPC/xprt: async tasks mustn't block waiting for memory") changed xprt_rdma_alloc_slot() to set tk_status to -ENOMEM so that call_reserveresult() would sleep HZ/4 before retrying. That rationale applies to xprt_dynamic_alloc_slot(), where an immediate retry under memory pressure wastes CPU, but not to the RDMA backlog path: a task woken from the backlog has a slot waiting for it, so the 250 ms rpc_delay adds latency without benefit. This also aligns the code with the existing kernel-doc for xprt_rdma_alloc_slot(), which already documented %-EAGAIN. Fixes: a721035477fb ("SUNRPC/xprt: async tasks mustn't block waiting for memory") Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust Stable-dep-of: e786233d2e0b ("xprtrdma: Decouple req recycling from RPC completion") Signed-off-by: Sasha Levin --- net/sunrpc/xprtrdma/transport.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c index 10bb2b929c6d70..80731cbb1365ee 100644 --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -520,7 +520,7 @@ xprt_rdma_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task) return; out_sleep: - task->tk_status = -ENOMEM; + task->tk_status = -EAGAIN; xprt_add_backlog(xprt, task); } -- 2.53.0