From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga04-in.huawei.com (szxga04-in.huawei.com [45.249.212.190]) (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 22FAE12AACD; Thu, 7 Mar 2024 12:28:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.190 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709814540; cv=none; b=mVsUI2yIbxTepVrcHzJ8w6hCyG9Nl0i1Gj3d1r3aqMADbvhq+J3egyDNp/vVm7JENPTxh4Q+XrZAeVtvhaWuUvOq3WZehv+WwtUB6lfSNauoL01VkT3Q/SCKVfcwrcJbPeplqBnCs+AQ8IuQA89Rcq64AIoncAkveks2NbiwCsU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709814540; c=relaxed/simple; bh=dVNW0oddv3N048br45hJLhMcLswgKfiqOYg11zbnmDY=; h=Subject:To:CC:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=duOmoVWd+uH22Ri9A9KQ+Zqc3JUsBDOQMbY8VWfhHTyxEM5HOU7+fj+DFB2qaJq+U/f/oyGVWoltkzVpP/yLnd4DHKkMtxGHOIHtl+FmUwDUDe7us2LIt+ykRcVN40xavccGLC6qFpvxJdlSGHaltsSKuRrUlRAa2/xGPaFXAnU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.190 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.234]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4Tr7pr2kmCz1xq8c; Thu, 7 Mar 2024 20:27:16 +0800 (CST) Received: from dggpemm500005.china.huawei.com (unknown [7.185.36.74]) by mail.maildlp.com (Postfix) with ESMTPS id 43254140336; Thu, 7 Mar 2024 20:28:55 +0800 (CST) Received: from [10.69.30.204] (10.69.30.204) by dggpemm500005.china.huawei.com (7.185.36.74) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Thu, 7 Mar 2024 20:28:54 +0800 Subject: Re: [RFC PATCH net-next v1 1/2] net: mirror skb frag ref/unref helpers To: Mina Almasry , , , CC: Mirko Lindner , Stephen Hemminger , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Tariq Toukan , Boris Pismenny , John Fastabend , Dragos Tatulea References: <20240306235922.282781-1-almasrymina@google.com> <20240306235922.282781-2-almasrymina@google.com> From: Yunsheng Lin Message-ID: <8ef17e46-3d14-e010-c721-6fca3d57f78f@huawei.com> Date: Thu, 7 Mar 2024 20:28:53 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20240306235922.282781-2-almasrymina@google.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500005.china.huawei.com (7.185.36.74) On 2024/3/7 7:59, Mina Almasry wrote: ... > > int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb, > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > index 1f918e602bc4..6d234faa9d9e 100644 > --- a/net/core/skbuff.c > +++ b/net/core/skbuff.c > @@ -1006,6 +1006,21 @@ int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb, > EXPORT_SYMBOL(skb_cow_data_for_xdp); > > #if IS_ENABLED(CONFIG_PAGE_POOL) > +bool napi_pp_get_page(struct page *page) > +{ > + > + struct page *head_page; > + > + head_page = compound_head(page); > + > + if (!is_pp_page(page)) I would use the head_page for is_pp_page(), I am not sure it matters that much, but I believe it is the precedent. Maybe do the below and remove head_page varible: page = compound_head(page); > + return false; > + > + page_pool_ref_page(head_page); > + return true; > +} > +EXPORT_SYMBOL(napi_pp_get_page); > + ... > - > static void skb_kfree_head(void *head, unsigned int end_offset) > { > if (end_offset == SKB_SMALL_HEAD_HEADROOM) > @@ -4199,7 +4183,7 @@ int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen) > to++; > > } else { > - __skb_frag_ref(fragfrom); > + __skb_frag_ref(fragfrom, skb->pp_recycle); > skb_frag_page_copy(fragto, fragfrom); > skb_frag_off_copy(fragto, fragfrom); > skb_frag_size_set(fragto, todo); > @@ -4849,7 +4833,7 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, > } > > *nskb_frag = (i < 0) ? skb_head_frag_to_page_desc(frag_skb) : *frag; > - __skb_frag_ref(nskb_frag); > + __skb_frag_ref(nskb_frag, nskb->pp_recycle); > size = skb_frag_size(nskb_frag); > > if (pos < offset) { > @@ -5980,10 +5964,8 @@ bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, > /* if the skb is not cloned this does nothing > * since we set nr_frags to 0. > */ > - if (skb_pp_frag_ref(from)) { I guess it worth mentioning that skb->pp_recycle is only checked once, and skb->pp_recycle is checked for every frag after this patch. > - for (i = 0; i < from_shinfo->nr_frags; i++) > - __skb_frag_ref(&from_shinfo->frags[i]); > - } > + for (i = 0; i < from_shinfo->nr_frags; i++) > + __skb_frag_ref(&from_shinfo->frags[i], from->pp_recycle); > > to->truesize += delta; > to->len += len; >