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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 86E96C433EF for ; Wed, 27 Apr 2022 19:04:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232259AbiD0TH7 (ORCPT ); Wed, 27 Apr 2022 15:07:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232563AbiD0THT (ORCPT ); Wed, 27 Apr 2022 15:07:19 -0400 Received: from mail-yb1-xb2f.google.com (mail-yb1-xb2f.google.com [IPv6:2607:f8b0:4864:20::b2f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA56D30F74 for ; Wed, 27 Apr 2022 11:55:10 -0700 (PDT) Received: by mail-yb1-xb2f.google.com with SMTP id w17so5040703ybh.9 for ; Wed, 27 Apr 2022 11:55:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=j3lBdD4GtdfuLMXUozbnDwowFFcjMZYRVPLsP+AgMcU=; b=nZjC+sPezdU6/sIyymL8+lboZ0eGQkFj48qM/Qjp/cuTUskAMS/udm47HLWj9IvxZc XInlUz4NInt8kiZ5Dzw/RV/ylrqHJxUqW5pz51Fyh6lGOvxZQbXlmajOczljkcClfQ6m 9h87VgQF0sAuCDUHk/kXI89Bs5r0vbeyRZwfr5li6y5Imah16Jy5CbDnGQ4YJubUYfyf vwL8CrE49NGXLlgSZPK9GukP16eqhvh2MpTWGbeYGfsc64gkB07ktFHsfKTKnagpa/ok JtZkQJ2LNVFtN45/JIpeVAJ2RKPu2mRMvEhf6E1Nnf9j+VY7femVp98QnzT33vNTj2DC RoYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=j3lBdD4GtdfuLMXUozbnDwowFFcjMZYRVPLsP+AgMcU=; b=joTebYDXjrthK1t7IyiX+Rj6OSSTQw6n72xnkH7frVcLw7XqIjdErcLd9p39Z4mL6Q A++/MRCJ4J/of/iE1Xrmwa5E72T+/Cskm+STfUTgczo4q/JR/MrNCrJtS9fvqyaS75Fc rYjsNu38s93fqiAc/buc7Dlt57d3wEGFJCrGsWZlYzL+wnyM7MTTRkCfWe0EKt3QiHIG QrHNXsON5HJaJSBDUWGNskZYnXqJz34xMI7cgYl2uJh6yVXuezX1MGSUskpgqOWQCecS 7sOzWHs6oHVKIV7KDkoWJ7DeZXKnPSq09lQ7Ml5/7108b4t3fLmhNHOQCZFoJ7q552QM D4TA== X-Gm-Message-State: AOAM5310NdnjU8sGYKTo7/vdN96eQR7aZOzkyrR9m5LvGEa44Qkd+pqo B9bHJ32FxLnpfRZblCkW6ko8fXd8F7UE6nKom+TNKw== X-Google-Smtp-Source: ABdhPJzHHPoayLSkVHp95DEYm6a44e5llK2VixyILwyrvUOLFsqrlfdfrZRTos9Yhc8iYa3UFHCT1YYaAr/cy41kCqc= X-Received: by 2002:a25:2a49:0:b0:648:f2b4:cd3d with SMTP id q70-20020a252a49000000b00648f2b4cd3dmr1024330ybq.231.1651085709765; Wed, 27 Apr 2022 11:55:09 -0700 (PDT) MIME-Version: 1.0 References: <20220422201237.416238-1-eric.dumazet@gmail.com> In-Reply-To: From: Eric Dumazet Date: Wed, 27 Apr 2022 11:54:58 -0700 Message-ID: Subject: Re: [PATCH v2 net-next] net: generalize skb freeing deferral to per-cpu lists To: Ido Schimmel Cc: Eric Dumazet , "David S . Miller" , Jakub Kicinski , Paolo Abeni , netdev Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Apr 27, 2022 at 10:59 AM Eric Dumazet wrote: > > On Wed, Apr 27, 2022 at 10:11 AM Eric Dumazet wrote: > > > > On Wed, Apr 27, 2022 at 9:53 AM Eric Dumazet wrote: > > > > > > On Wed, Apr 27, 2022 at 8:34 AM Ido Schimmel wrote: > > > > > > > > > > > > > > > Eric, with this patch I'm seeing memory leaks such as these [1][2] after > > > > boot. The system is using the igb driver for its management interface > > > > [3]. The leaks disappear after reverting the patch. > > > > > > > > Any ideas? > > > > > > > > > > No idea, skbs allocated to send an ACK can not be stored in receive > > > queue, I guess this is a kmemleak false positive. > > > > > > Stress your host for hours, and check if there are real kmemleaks, as > > > in memory being depleted. > > > > AT first when I saw your report I wondered if the following was needed, > > but I do not think so. Nothing in __kfree_skb(skb) cares about skb->next. > > > > But you might give it a try, maybe I am wrong. > > > > diff --git a/net/core/dev.c b/net/core/dev.c > > index 611bd719706412723561c27753150b27e1dc4e7a..9dc3443649b962586cc059899ac3d71e9c7a3559 > > 100644 > > --- a/net/core/dev.c > > +++ b/net/core/dev.c > > @@ -6594,6 +6594,7 @@ static void skb_defer_free_flush(struct softnet_data *sd) > > > > while (skb != NULL) { > > next = skb->next; > > + skb_mark_not_on_list(skb); > > __kfree_skb(skb); > > skb = next; > > } > > Oh well, there is definitely a leak, sorry for that. Ido, can you test if the following patch solves your issue ? It definitely looks needed. Thanks ! diff --git a/net/core/dev.c b/net/core/dev.c index 611bd719706412723561c27753150b27e1dc4e7a..e09cd202fc579dfe2313243e20def8044aafafa2 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6617,7 +6617,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) if (list_empty(&list)) { if (!sd_has_rps_ipi_waiting(sd) && list_empty(&repoll)) - return; + goto end; break; } @@ -6644,6 +6644,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) __raise_softirq_irqoff(NET_RX_SOFTIRQ); net_rps_action_and_irq_enable(sd); +end: skb_defer_free_flush(sd); }