From patchwork Fri Jul 14 17:08:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Lobakin X-Patchwork-Id: 13313865 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 A6C1E15AC6 for ; Fri, 14 Jul 2023 17:10:37 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50C973A87; Fri, 14 Jul 2023 10:10:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689354634; x=1720890634; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=J4oLah63yJ0HDb0vEWkMBT8p/z6UYrzti87G1AcWpXY=; b=Djg7n3Fvxdp8jvnHwfgU+PhHXskCmVElSd0peTEQ/YySImKS2ctG6OCE Ds23HmqEOZ27Dwn4SB47086yrerxQLBDG1emJAqXshENxJrBtGDnpZ0tG RXKMperp9IsnTHwmqpOIJfR2/Eb3jcoamx6Ac/+KRCcHX5xiv/dPxIpKc 9aGHYrU/LeVCAYDdLlAvkeA27g7WNGXSc3vq2MgxXvy/YqQACqEeeEGes ZtL/+OCfeqJHUnhnGRcJdf5ttydkethQhAIrsXJqDR6qfc2KyqR/96DTo YK9wCqBtVVzTsOVZMSaB31XZDyRtHc6oAlrUnT6IB1qgP24VnSkzc1GLs Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10771"; a="451891877" X-IronPort-AV: E=Sophos;i="6.01,206,1684825200"; d="scan'208";a="451891877" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jul 2023 10:10:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10771"; a="787907035" X-IronPort-AV: E=Sophos;i="6.01,206,1684825200"; d="scan'208";a="787907035" Received: from newjersey.igk.intel.com ([10.102.20.203]) by fmsmga008.fm.intel.com with ESMTP; 14 Jul 2023 10:10:30 -0700 From: Alexander Lobakin To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Alexander Lobakin , Maciej Fijalkowski , Larysa Zaremba , Yunsheng Lin , Alexander Duyck , Jesper Dangaard Brouer , Ilias Apalodimas , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH RFC net-next v2 3/7] net: page_pool: place frag_* fields in one cacheline Date: Fri, 14 Jul 2023 19:08:47 +0200 Message-ID: <20230714170853.866018-5-aleksander.lobakin@intel.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230714170853.866018-1-aleksander.lobakin@intel.com> References: <20230714170853.866018-1-aleksander.lobakin@intel.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC On x86_64, frag_* fields of struct page_pool are scattered across two cachelines despite the summary size of 24 bytes. The last field, ::frag_users, is pushed out to the next one, sharing it with ::alloc_stats. All three fields are used in pretty much same places. There are some holes and cold members to move around. Move frag_* one block up, placing them right after &page_pool_params perfectly at the beginning of CL2. This doesn't do any meaningful to the second block, as those are some destroy-path cold structures, and doesn't do anything to ::alloc_stats, which still starts at 200 byte offset, 8 bytes after CL3 (still fitting into 1 cacheline). On my setup, this yields 1-2% of Mpps when using PP frags actively. When it comes to 32-bit architectures with 32 byte CL: &page_pool_params plus ::pad is 44 bytes, the block taken care of is 16 bytes within one CL, so there should be at least no regressions from the actual change. Signed-off-by: Alexander Lobakin --- include/net/page_pool.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/include/net/page_pool.h b/include/net/page_pool.h index 69e822021d95..68937deea4b1 100644 --- a/include/net/page_pool.h +++ b/include/net/page_pool.h @@ -131,16 +131,16 @@ struct page_pool { struct page_pool_params p; long pad; + long frag_users; + struct page *frag_page; + unsigned int frag_offset; + u32 pages_state_hold_cnt; + struct delayed_work release_dw; void (*disconnect)(void *); unsigned long defer_start; unsigned long defer_warn; - u32 pages_state_hold_cnt; - unsigned int frag_offset; - struct page *frag_page; - long frag_users; - #ifdef CONFIG_PAGE_POOL_STATS /* these stats are incremented while in softirq context */ struct page_pool_alloc_stats alloc_stats;