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 X-Spam-Level: X-Spam-Status: No, score=-12.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D51DC4338F for ; Fri, 13 Aug 2021 18:01:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4EE060F14 for ; Fri, 13 Aug 2021 18:01:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231960AbhHMSCF (ORCPT ); Fri, 13 Aug 2021 14:02:05 -0400 Received: from dispatch1-us1.ppe-hosted.com ([67.231.154.184]:45944 "EHLO dispatch1-us1.ppe-hosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229829AbhHMSCE (ORCPT ); Fri, 13 Aug 2021 14:02:04 -0400 X-Virus-Scanned: Proofpoint Essentials engine Received: from mx1-us1.ppe-hosted.com (unknown [10.110.51.164]) by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTPS id 0DE4DA0074; Fri, 13 Aug 2021 18:01:36 +0000 (UTC) Received: from mail3.candelatech.com (mail2.candelatech.com [208.74.158.173]) by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTP id C7429B00078; Fri, 13 Aug 2021 18:01:35 +0000 (UTC) Received: from [192.168.254.6] (unknown [50.34.183.227]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail3.candelatech.com (Postfix) with ESMTPSA id 504B713C2B1; Fri, 13 Aug 2021 11:01:34 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 mail3.candelatech.com 504B713C2B1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=candelatech.com; s=default; t=1628877695; bh=QvPsfM9+KiEouJA3to7Ayd5foMmgyB+dmM7sn1vMuwY=; h=Subject:To:References:From:Date:In-Reply-To:From; b=U16g1U3A8HezMXskh83Lf86HBfLjtVduDv5V6Bkgt2fpkvOnLRiY6OrXC5sBrYDo7 rB/qmN1gZeWzP42aBuRB77kTnMOOX+wfoEzm1roILKcJdq0VZ8vQav+qP0jFBsDK40 HS3tf0Wjm+ENkYzLKfgFKSZlA4fgVbWXWaiF2uyc= Subject: Re: [PATCH v5 01/11] mt76: add hash lookup for skb on TXS status_list To: Felix Fietkau , linux-wireless@vger.kernel.org References: <20210804134505.3208-1-greearb@candelatech.com> <0a7e7206-91c0-35a9-8935-20bc6283367f@candelatech.com> From: Ben Greear Organization: Candela Technologies Message-ID: <97657c37-8920-c8ba-a05c-28552ab71967@candelatech.com> Date: Fri, 13 Aug 2021 11:01:29 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-MW Content-Transfer-Encoding: 7bit X-MDID: 1628877696-4WsnDSdffVt3 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On 8/13/21 10:46 AM, Felix Fietkau wrote: >>>> diff --git a/drivers/net/wireless/mediatek/mt76/tx.c b/drivers/net/wireless/mediatek/mt76/tx.c >>>> index 6f302acb6e69..4c8504d3c904 100644 >>>> --- a/drivers/net/wireless/mediatek/mt76/tx.c >>>> +++ b/drivers/net/wireless/mediatek/mt76/tx.c >>>> @@ -130,15 +154,30 @@ mt76_tx_status_skb_add(struct mt76_dev *dev, struct mt76_wcid *wcid, >>>> IEEE80211_TX_CTL_RATE_CTRL_PROBE))) >>>> return MT_PACKET_ID_NO_SKB; >>>> >>>> + /* due to limited range of the pktid (7 bits), we can only >>>> + * have a limited number of outstanding frames. I think it is OK to >>>> + * check the length outside of a lock since it doesn't matter too much >>>> + * if we read wrong data here. >>>> + * The TX-status callbacks don't always return a callback for an SKB, >>>> + * so the status_list may contain some stale skbs. Those will be cleaned >>>> + * out periodically, see MT_TX_STATUS_SKB_TIMEOUT. >>>> + */ >>>> + >>>> + qlen = skb_queue_len(&dev->status_list); >>>> + if (qlen > 120) >>>> + return MT_PACKET_ID_NO_SKB; >>> Checking the length of the per-device status list doesn't make sense, >>> since pktid allocation is per-wcid. >> >> Ok, so just remove this code, or should I set some other higher >> limit to bound the list? > You could just check for a duplicate skb_status_array entry. Ok, that will happen anyway when searching for next wcid pkt-id. The check above was a quick bail-out before locks were acquired. I'll just remove that qlen check... Thanks, Ben > > - Felix > -- Ben Greear Candela Technologies Inc http://www.candelatech.com