From patchwork Thu Feb 7 22:36:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Coelho X-Patchwork-Id: 10802211 X-Patchwork-Delegate: luca@coelho.fi Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 115366C2 for ; Thu, 7 Feb 2019 22:36:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F42072E0E9 for ; Thu, 7 Feb 2019 22:36:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E51802E782; Thu, 7 Feb 2019 22:36:39 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 77B742E775 for ; Thu, 7 Feb 2019 22:36:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726821AbfBGWgj (ORCPT ); Thu, 7 Feb 2019 17:36:39 -0500 Received: from paleale.coelho.fi ([176.9.41.70]:56560 "EHLO farmhouse.coelho.fi" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726622AbfBGWgi (ORCPT ); Thu, 7 Feb 2019 17:36:38 -0500 Received: from 91-156-4-241.elisa-laajakaista.fi ([91.156.4.241] helo=redipa.ger.corp.intel.com) by farmhouse.coelho.fi with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.91) (envelope-from ) id 1grsHd-0002II-31; Fri, 08 Feb 2019 00:36:37 +0200 From: Luca Coelho To: kvalo@codeaurora.org Cc: linux-wireless@vger.kernel.org, Sara Sharon , Ilan Peer , Luca Coelho Date: Fri, 8 Feb 2019 00:36:07 +0200 Message-Id: <20190207223622.9642-3-luca@coelho.fi> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190207223622.9642-1-luca@coelho.fi> References: <20190207223622.9642-1-luca@coelho.fi> MIME-Version: 1.0 Subject: [PATCH 02/17] iwlwifi: pcie: fix emergency path Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Sara Sharon Allocator swaps the pending requests with 0 when it starts working. This means that relying on it n RX path to decide if to move to emergency is not always a good idea, since it may be zero, but there are still a lot of unallocated RBs in the system. Change allocator to decrement the pending requests on real time. It is more expensive since it accesses the atomic variable more times, but it gives the RX path a better idea of the system's status. Reported-by: Ilan Peer Signed-off-by: Sara Sharon Fixes: 868a1e863f95 ("iwlwifi: pcie: avoid empty free RB queue") Signed-off-by: Luca Coelho --- drivers/net/wireless/intel/iwlwifi/pcie/rx.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c index c260d1251b5f..36cbfed409d0 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c @@ -538,7 +538,7 @@ static void iwl_pcie_rx_allocator(struct iwl_trans *trans) struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); struct iwl_rb_allocator *rba = &trans_pcie->rba; struct list_head local_empty; - int pending = atomic_xchg(&rba->req_pending, 0); + int pending = atomic_read(&rba->req_pending); IWL_DEBUG_RX(trans, "Pending allocation requests = %d\n", pending); @@ -593,11 +593,13 @@ static void iwl_pcie_rx_allocator(struct iwl_trans *trans) i++; } + atomic_dec(&rba->req_pending); pending--; + if (!pending) { - pending = atomic_xchg(&rba->req_pending, 0); + pending = atomic_read(&rba->req_pending); IWL_DEBUG_RX(trans, - "Pending allocation requests = %d\n", + "Got more pending allocation requests = %d\n", pending); } @@ -609,12 +611,15 @@ static void iwl_pcie_rx_allocator(struct iwl_trans *trans) spin_unlock(&rba->lock); atomic_inc(&rba->req_ready); + } spin_lock(&rba->lock); /* return unused rbds to the allocator empty list */ list_splice_tail(&local_empty, &rba->rbd_empty); spin_unlock(&rba->lock); + + IWL_DEBUG_RX(trans, "%s, exit.\n", __func__); } /*