From patchwork Wed Feb 24 18:56:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jesper Dangaard Brouer X-Patchwork-Id: 12102281 X-Patchwork-Delegate: kuba@kernel.org 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=-20.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 5AE3FC433DB for ; Wed, 24 Feb 2021 19:00:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0109B64F0F for ; Wed, 24 Feb 2021 19:00:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235644AbhBXS7b (ORCPT ); Wed, 24 Feb 2021 13:59:31 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:53376 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235276AbhBXS6X (ORCPT ); Wed, 24 Feb 2021 13:58:23 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614193015; 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=J2GT3Unh95elqMpldeh7zjbELEnC6JldM1jdV32+9t4=; b=FbrddVRPscMGIQ9iVfEBvL9uUXyFScTh8qwW1gubGlVuOzaC820q7NVH13RcSJhrRz/CJt qir5jBcqI1zXVI2xG3uk/uTL6ym9npXUvIgKDt4UEGWD1aj4xyllGCHBCLHc3s0SOT1Rtb EilEup0wrIdc+e/03oQidx3uiaS8yTM= 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-232-Tbd4enyCNjavKWsUbBV3mg-1; Wed, 24 Feb 2021 13:56:51 -0500 X-MC-Unique: Tbd4enyCNjavKWsUbBV3mg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 72FCC1087D61; Wed, 24 Feb 2021 18:56:50 +0000 (UTC) Received: from firesoul.localdomain (unknown [10.40.208.7]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4C61F60BE5; Wed, 24 Feb 2021 18:56:47 +0000 (UTC) Received: from [192.168.42.3] (localhost [IPv6:::1]) by firesoul.localdomain (Postfix) with ESMTP id 3F99D30736C73; Wed, 24 Feb 2021 19:56:46 +0100 (CET) Subject: [PATCH RFC net-next 2/3] net: page_pool: use alloc_pages_bulk in refill code path From: Jesper Dangaard Brouer To: Mel Gorman , linux-mm@kvack.org Cc: Jesper Dangaard Brouer , chuck.lever@oracle.com, netdev@vger.kernel.org, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 24 Feb 2021 19:56:46 +0100 Message-ID: <161419300618.2718959.11165518489200268845.stgit@firesoul> In-Reply-To: <161419296941.2718959.12575257358107256094.stgit@firesoul> References: <161419296941.2718959.12575257358107256094.stgit@firesoul> User-Agent: StGit/0.19 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC There are cases where the page_pool need to refill with pages from the page allocator. Some workloads cause the page_pool to release pages instead of recycling these pages. For these workload it can improve performance to bulk alloc pages from the page-allocator to refill the alloc cache. For XDP-redirect workload with 100G mlx5 driver (that use page_pool) redirecting xdp_frame packets into a veth, that does XDP_PASS to create an SKB from the xdp_frame, which then cannot return the page to the page_pool. In this case, we saw[1] an improvement of 18.8% from using the alloc_pages_bulk API (3,677,958 pps -> 4,368,926 pps). [1] https://github.com/xdp-project/xdp-project/blob/master/areas/mem/page_pool06_alloc_pages_bulk.org Signed-off-by: Jesper Dangaard Brouer --- net/core/page_pool.c | 65 ++++++++++++++++++++++++++++++++------------------ 1 file changed, 41 insertions(+), 24 deletions(-) diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 50d52aa6fbeb..e0ae95fc59f0 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -210,44 +210,61 @@ noinline static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, gfp_t _gfp) { - struct page *page; + const int bulk = PP_ALLOC_CACHE_REFILL; + struct page *page, *next, *first_page; + unsigned int pp_flags = pool->p.flags; + unsigned int pp_order = pool->p.order; + int pp_nid = pool->p.nid; + LIST_HEAD(page_list); gfp_t gfp = _gfp; - /* We could always set __GFP_COMP, and avoid this branch, as - * prep_new_page() can handle order-0 with __GFP_COMP. - */ - if (pool->p.order) + /* Don't support bulk alloc for high-order pages */ + if (unlikely(pp_order)) { gfp |= __GFP_COMP; + first_page = alloc_pages_node(pp_nid, gfp, pp_order); + if (unlikely(!first_page)) + return NULL; + goto out; + } - /* FUTURE development: - * - * Current slow-path essentially falls back to single page - * allocations, which doesn't improve performance. This code - * need bulk allocation support from the page allocator code. - */ - - /* Cache was empty, do real allocation */ -#ifdef CONFIG_NUMA - page = alloc_pages_node(pool->p.nid, gfp, pool->p.order); -#else - page = alloc_pages(gfp, pool->p.order); -#endif - if (!page) + if (unlikely(!__alloc_pages_bulk_nodemask(gfp, pp_nid, NULL, + bulk, &page_list))) return NULL; + /* First page is extracted and returned to caller */ + first_page = list_first_entry(&page_list, struct page, lru); + list_del(&first_page->lru); + + /* Remaining pages store in alloc.cache */ + list_for_each_entry_safe(page, next, &page_list, lru) { + list_del(&page->lru); + if (pp_flags & PP_FLAG_DMA_MAP) { + page = page_pool_dma_map(pool, page); + if (!page) + continue; + } + if (likely(pool->alloc.count < PP_ALLOC_CACHE_SIZE)) { + pool->alloc.cache[pool->alloc.count++] = page; + pool->pages_state_hold_cnt++; + trace_page_pool_state_hold(pool, page, + pool->pages_state_hold_cnt); + } else { + put_page(page); + } + } +out: if (pool->p.flags & PP_FLAG_DMA_MAP) { - page = page_pool_dma_map(pool, page); - if (!page) + first_page = page_pool_dma_map(pool, first_page); + if (!first_page) return NULL; } /* Track how many pages are held 'in-flight' */ pool->pages_state_hold_cnt++; - - trace_page_pool_state_hold(pool, page, pool->pages_state_hold_cnt); + trace_page_pool_state_hold(pool, first_page, pool->pages_state_hold_cnt); /* When page just alloc'ed is should/must have refcnt 1. */ - return page; + return first_page; } /* For using page_pool replace: alloc_pages() API calls, but provide