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=-6.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS 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 8773FC43381 for ; Sun, 24 Mar 2019 16:54:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 319F020870 for ; Sun, 24 Mar 2019 16:54:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=nbd.name header.i=@nbd.name header.b="t8GYhf8A" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728856AbfCXQyL (ORCPT ); Sun, 24 Mar 2019 12:54:11 -0400 Received: from nbd.name ([46.4.11.11]:36032 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727960AbfCXQyL (ORCPT ); Sun, 24 Mar 2019 12:54:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=nbd.name; s=20160729; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=aZKPAZ0Zr8hCrit2gBNoyndf4HdHnHHWfK67qijQlY8=; b=t8GYhf8Ap6ihC9BjBpcNJHfhj1 xpLfNmtXjnbf+4/laUMm7HncWWEMWIQxFHJxUH5ufUba1wm6JWHF8Tiw6RHdKAtMZRvH6T4qF4iVA 76Np87jBzepmhlHt17pFUY4VFtoo+KWaw0sh5tmZjyn941nmcHKZ3H6PGJRPMkogy4Ic=; Received: from p4ff13c7c.dip0.t-ipconnect.de ([79.241.60.124] helo=nf.local) by ds12 with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1h86Nr-0002MR-MT; Sun, 24 Mar 2019 17:54:07 +0100 Subject: Re: [PATCH net-next] net: use bulk free in kfree_skb_list To: Jesper Dangaard Brouer Cc: netdev@vger.kernel.org, davem@davemloft.net, Florian Westphal References: <20190324065834.89272-1-nbd@nbd.name> <20190324123130.7b86487a@carbon> From: Felix Fietkau Openpgp: preference=signencrypt Autocrypt: addr=nbd@nbd.name; prefer-encrypt=mutual; keydata= mQGiBEah5CcRBADIY7pu4LIv3jBlyQ/2u87iIZGe6f0f8pyB4UjzfJNXhJb8JylYYRzIOSxh ExKsdLCnJqsG1PY1mqTtoG8sONpwsHr2oJ4itjcGHfn5NJSUGTbtbbxLro13tHkGFCoCr4Z5 Pv+XRgiANSpYlIigiMbOkide6wbggQK32tC20QxUIwCg4k6dtV/4kwEeiOUfErq00TVqIiEE AKcUi4taOuh/PQWx/Ujjl/P1LfJXqLKRPa8PwD4j2yjoc9l+7LptSxJThL9KSu6gtXQjcoR2 vCK0OeYJhgO4kYMI78h1TSaxmtImEAnjFPYJYVsxrhay92jisYc7z5R/76AaELfF6RCjjGeP wdalulG+erWju710Bif7E1yjYVWeA/9Wd1lsOmx6uwwYgNqoFtcAunDaMKi9xVQW18FsUusM TdRvTZLBpoUAy+MajAL+R73TwLq3LnKpIcCwftyQXK5pEDKq57OhxJVv1Q8XkA9Dn1SBOjNB l25vJDFAT9ntp9THeDD2fv15yk4EKpWhu4H00/YX8KkhFsrtUs69+vZQwbQcRmVsaXggRmll dGthdSA8bmJkQG5iZC5uYW1lPohgBBMRAgAgBQJGoeQnAhsjBgsJCAcDAgQVAggDBBYCAwEC HgECF4AACgkQ130UHQKnbvXsvgCgjsAIIOsY7xZ8VcSm7NABpi91yTMAniMMmH7FRenEAYMa VrwYTIThkTlQuQINBEah5FQQCACMIep/hTzgPZ9HbCTKm9xN4bZX0JjrqjFem1Nxf3MBM5vN CYGBn8F4sGIzPmLhl4xFeq3k5irVg/YvxSDbQN6NJv8o+tP6zsMeWX2JjtV0P4aDIN1pK2/w VxcicArw0VYdv2ZCarccFBgH2a6GjswqlCqVM3gNIMI8ikzenKcso8YErGGiKYeMEZLwHaxE Y7mTPuOTrWL8uWWRL5mVjhZEVvDez6em/OYvzBwbkhImrryF29e3Po2cfY2n7EKjjr3/141K DHBBdgXlPNfDwROnA5ugjjEBjwkwBQqPpDA7AYPvpHh5vLbZnVGu5CwG7NAsrb2isRmjYoqk wu++3117AAMFB/9S0Sj7qFFQcD4laADVsabTpNNpaV4wAgVTRHKV/kC9luItzwDnUcsZUPdQ f3MueRJ3jIHU0UmRBG3uQftqbZJj3ikhnfvyLmkCNe+/hXhPu9sGvXyi2D4vszICvc1KL4RD aLSrOsROx22eZ26KqcW4ny7+va2FnvjsZgI8h4sDmaLzKczVRIiLITiMpLFEU/VoSv0m1F4B FtRgoiyjFzigWG0MsTdAN6FJzGh4mWWGIlE7o5JraNhnTd+yTUIPtw3ym6l8P+gbvfoZida0 TspgwBWLnXQvP5EDvlZnNaKa/3oBes6z0QdaSOwZCRA3QSLHBwtgUsrT6RxRSweLrcabiEkE GBECAAkFAkah5FQCGwwACgkQ130UHQKnbvW2GgCfTKx80VvCR/PvsUlrvdOLsIgeRGAAn1ee RjMaxwtSdaCKMw3j33ZbsWS4 Message-ID: Date: Sun, 24 Mar 2019 17:54:06 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:60.0) Gecko/20100101 Thunderbird/60.6.0 MIME-Version: 1.0 In-Reply-To: <20190324123130.7b86487a@carbon> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2019-03-24 12:31, Jesper Dangaard Brouer wrote: > On Sun, 24 Mar 2019 07:58:34 +0100 > Felix Fietkau wrote: > >> Since we're freeing multiple skbs, we might as well use bulk free to save a >> few cycles. Use the same conditions for bulk free as in napi_consume_skb. >> >> Signed-off-by: Felix Fietkau > > Thanks for working on this, it's been on my todo list for a very long > time. I just discussed this with Florian at NetDevconf. No problem. It was showing up on my perf traces while improving mac80211/mt76 performance, so I decided to deal with it now :) >> diff --git a/net/core/skbuff.c b/net/core/skbuff.c >> index 2415d9cb9b89..ec030ab7f1e7 100644 >> --- a/net/core/skbuff.c >> +++ b/net/core/skbuff.c >> @@ -666,12 +666,39 @@ EXPORT_SYMBOL(kfree_skb); >> >> void kfree_skb_list(struct sk_buff *segs) >> { >> - while (segs) { >> - struct sk_buff *next = segs->next; >> + struct sk_buff *next = segs; >> + void *skbs[16]; >> + int n_skbs = 0; >> >> - kfree_skb(segs); >> - segs = next; >> + while ((segs = next) != NULL) { >> + next = segs->next; >> + >> + if (!skb_unref(segs)) >> + continue; >> + >> + if (segs->fclone != SKB_FCLONE_UNAVAILABLE || >> + n_skbs >= ARRAY_SIZE(skbs)) { > > You could call kmem_cache_free_bulk() here and reset n_skbs=0. Sure, good idea. I'll send v2 shortly. - Felix