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=-6.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 51B0CC388F7 for ; Wed, 4 Nov 2020 12:24:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C381121734 for ; Wed, 4 Nov 2020 12:24:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Sg361rPK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729804AbgKDMYy (ORCPT ); Wed, 4 Nov 2020 07:24:54 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:34742 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726344AbgKDMYx (ORCPT ); Wed, 4 Nov 2020 07:24:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1604492692; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=OoCAW5bYOrSTsyToPsJ15TqE4jwYO9Qy/CvnKeekXrI=; b=Sg361rPKy3F+nkuhZcyYnBtyAfrpIywc+CdoiOMmEvPKWSj3fSZBNSQIMDsYaQMLzs/vPF a7/Bd6iWUACkKwpN5Q3ExBO6xsJkvpD2wgaLCc6B7UvR3fBg6sUjxBotSbmuaLRjIKfWrm xmLkLKrnjyPGRmbGI9B6oFMc45TRXyQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-542-qx5xiX-UOju6eqjokG9sVA-1; Wed, 04 Nov 2020 07:24:48 -0500 X-MC-Unique: qx5xiX-UOju6eqjokG9sVA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 84DEB8797D3; Wed, 4 Nov 2020 12:24:46 +0000 (UTC) Received: from carbon (unknown [10.36.110.25]) by smtp.corp.redhat.com (Postfix) with ESMTP id B94DF6266E; Wed, 4 Nov 2020 12:24:32 +0000 (UTC) Date: Wed, 4 Nov 2020 13:24:30 +0100 From: Jesper Dangaard Brouer To: Lorenzo Bianconi Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, lorenzo.bianconi@redhat.com, davem@davemloft.net, kuba@kernel.org, ilias.apalodimas@linaro.org, brouer@redhat.com Subject: Re: [PATCH v3 net-next 2/5] net: page_pool: add bulk support for ptr_ring Message-ID: <20201104132430.73594bb6@carbon> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 4 Nov 2020 11:22:55 +0100 Lorenzo Bianconi wrote: > diff --git a/net/core/page_pool.c b/net/core/page_pool.c > index ef98372facf6..236c5ed3aa66 100644 > --- a/net/core/page_pool.c > +++ b/net/core/page_pool.c [...] > @@ -408,6 +410,39 @@ void page_pool_put_page(struct page_pool *pool, struct page *page, > } > EXPORT_SYMBOL(page_pool_put_page); > > +void page_pool_put_page_bulk(struct page_pool *pool, void **data, > + int count) > +{ > + int i, len = 0; > + > + for (i = 0; i < count; i++) { > + struct page *page = virt_to_head_page(data[i]); > + > + if (likely(page_ref_count(page) == 1 && > + pool_page_reusable(pool, page))) { > + if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) > + page_pool_dma_sync_for_device(pool, page, -1); > + > + /* bulk pages for ptr_ring cache */ > + data[len++] = page; > + } else { > + page_pool_release_page(pool, page); > + put_page(page); > + } > + } > + > + /* Grab the producer spinlock for concurrent access to > + * ptr_ring page_pool cache > + */ > + page_pool_ring_lock(pool); > + for (i = 0; i < len; i++) { > + if (__ptr_ring_produce(&pool->ring, data[i])) > + page_pool_return_page(pool, data[i]); > + } > + page_pool_ring_unlock(pool); > +} > +EXPORT_SYMBOL(page_pool_put_page_bulk); I don't like that you are replicating the core logic from page_pool_put_page() in this function. This means that we as maintainers need to keep both of this places up-to-date. Let me try to re-implement this, while sharing the refcnt logic: (completely untested, not even compiled) --- net/core/page_pool.c | 58 +++++++++++++++++++++++++++++++++++++++++++------- 2 files changed, 51 insertions(+), 9 deletions(-) diff --git a/net/core/page_pool.c b/net/core/page_pool.c index ef98372facf6..c785e9825a0d 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -362,8 +362,9 @@ static bool pool_page_reusable(struct page_pool *pool, struct page *page) * If the page refcnt != 1, then the page will be returned to memory * subsystem. */ -void page_pool_put_page(struct page_pool *pool, struct page *page, - unsigned int dma_sync_size, bool allow_direct) +static struct page* +__page_pool_put_page(struct page_pool *pool, struct page *page, + unsigned int dma_sync_size, bool allow_direct) { /* This allocator is optimized for the XDP mode that uses * one-frame-per-page, but have fallbacks that act like the @@ -381,13 +382,10 @@ void page_pool_put_page(struct page_pool *pool, struct page *page, if (allow_direct && in_serving_softirq()) if (page_pool_recycle_in_cache(page, pool)) - return; + return NULL; - if (!page_pool_recycle_in_ring(pool, page)) { - /* Cache full, fallback to free pages */ - page_pool_return_page(pool, page); - } - return; + /* Page found as candidate for recycling */ + return page; } /* Fallback/non-XDP mode: API user have elevated refcnt. * @@ -405,9 +403,53 @@ void page_pool_put_page(struct page_pool *pool, struct page *page, /* Do not replace this with page_pool_return_page() */ page_pool_release_page(pool, page); put_page(page); + return NULL; +} + +void page_pool_put_page(struct page_pool *pool, struct page *page, + unsigned int dma_sync_size, bool allow_direct) +{ + page = __page_pool_put_page(pool, page, dma_sync_size, allow_direct); + + if (page && !page_pool_recycle_in_ring(pool, page)) { + /* Cache full, fallback to free pages */ + page_pool_return_page(pool, page); + } } EXPORT_SYMBOL(page_pool_put_page); +/* Caller must not use data area after call, as this function overwrites it */ +void page_pool_put_page_bulk(struct page_pool *pool, void **data, int count) +{ + int i, len = 0, len2 = 0; + + for (i = 0; i < count; i++) { + struct page *page = virt_to_head_page(data[i]); + + page = __page_pool_put_page(pool, page, -1 , false); + + /* Approved for recycling for ptr_ring cache */ + if (page) + data[len++] = page; + } + + /* Bulk producer into ptr_ring page_pool cache */ + page_pool_ring_lock(pool); + for (i = 0; i < len; i++) { + if (__ptr_ring_produce(&pool->ring, data[i])) + data[len2++] = data[i]; + } + page_pool_ring_unlock(pool); + + /* Unlikely case of ptr_ring cache full, free pages outside producer + * lock, given put_page() with refcnt==1 can be an expensive operation. + */ + for (i = 0; i < len2; i++) { + page_pool_return_page(pool, data[i]); + } +} +EXPORT_SYMBOL(page_pool_put_page_bulk); + static void page_pool_empty_ring(struct page_pool *pool) { struct page *page; -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer