From patchwork Sun Nov 26 23:07:27 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Kicinski X-Patchwork-Id: 13468940 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 20E05D51A for ; Sun, 26 Nov 2023 23:08:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VRcotU4m" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 269EEC433C8; Sun, 26 Nov 2023 23:08:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1701040096; bh=sxW3nE0OFYnVrBcDyvPZeVDLSa+EGVEA0q4uRk8DikA=; h=From:To:Cc:Subject:Date:From; b=VRcotU4m2OJiGzE2FXY+uqxGsmykDq4gR5GYr+/+zT9Rg3sCsx5iNJ4TS/emHKK7e JFIBNqjkulbRSMKXgrSeXMWBZWiH7+I1x8LGuXlNSxMB9E8xE9aK24y3jOe6ZZE6xu bQeCQ69eMZnVgFKPtG0B7B1k7HAlXXaTXPzNQAMy3np05pXyXo7oOVUCfPHmYT7xCg OoQ3ESmcjmlEh7dXsXD+Aywb35S60NAdw+XIFO7cr28JTN0+o381pVlRtrhV4fzBZj doo8DOBtjn/+J6zlNVjLC7RCCA0eAK6nAtg4zZQOCfUWTLrbspP93Fqcpe6PMDVqlJ D+KD54hwL2jig== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, hawk@kernel.org, ilias.apalodimas@linaro.org, dsahern@gmail.com, dtatulea@nvidia.com, willemb@google.com, almasrymina@google.com, shakeelb@google.com, Jakub Kicinski Subject: [PATCH net-next v4 00/13] net: page_pool: add netlink-based introspection Date: Sun, 26 Nov 2023 15:07:27 -0800 Message-ID: <20231126230740.2148636-1-kuba@kernel.org> X-Mailer: git-send-email 2.42.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org We recently started to deploy newer kernels / drivers at Meta, making significant use of page pools for the first time. We immediately run into page pool leaks both real and false positive warnings. As Eric pointed out/predicted there's no guarantee that applications will read / close their sockets so a page pool page may be stuck in a socket (but not leaked) forever. This happens a lot in our fleet. Most of these are obviously due to application bugs but we should not be printing kernel warnings due to minor application resource leaks. Conversely the page pool memory may get leaked at runtime, and we have no way to detect / track that, unless someone reconfigures the NIC and destroys the page pools which leaked the pages. The solution presented here is to expose the memory use of page pools via netlink. This allows for continuous monitoring of memory used by page pools, regardless if they were destroyed or not. Sample in patch 15 can print the memory use and recycling efficiency: $ ./page-pool eth0[2] page pools: 10 (zombies: 0) refs: 41984 bytes: 171966464 (refs: 0 bytes: 0) recycling: 90.3% (alloc: 656:397681 recycle: 89652:270201) v4: - use dev_net(netdev)->loopback_dev - extend inflight doc v3: https://lore.kernel.org/all/20231122034420.1158898-1-kuba@kernel.org/ - ID is still here, can't decide if it matters - rename destroyed -> detach-time, good enough? - fix build for netsec v2: https://lore.kernel.org/r/20231121000048.789613-1-kuba@kernel.org - hopefully fix build with PAGE_POOL=n v1: https://lore.kernel.org/all/20231024160220.3973311-1-kuba@kernel.org/ - The main change compared to the RFC is that the API now exposes outstanding references and byte counts even for "live" page pools. The warning is no longer printed if page pool is accessible via netlink. RFC: https://lore.kernel.org/all/20230816234303.3786178-1-kuba@kernel.org/ Jakub Kicinski (13): net: page_pool: factor out uninit net: page_pool: id the page pools net: page_pool: record pools per netdev net: page_pool: stash the NAPI ID for easier access eth: link netdev to page_pools in drivers net: page_pool: add nlspec for basic access to page pools net: page_pool: implement GET in the netlink API net: page_pool: add netlink notifications for state changes net: page_pool: report amount of memory held by page pools net: page_pool: report when page pool was destroyed net: page_pool: expose page pool stats via netlink net: page_pool: mute the periodic warning for visible page pools tools: ynl: add sample for getting page-pool information Documentation/netlink/specs/netdev.yaml | 172 +++++++ Documentation/networking/page_pool.rst | 10 +- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 1 + .../net/ethernet/mellanox/mlx5/core/en_main.c | 1 + drivers/net/ethernet/microsoft/mana/mana_en.c | 1 + drivers/net/ethernet/socionext/netsec.c | 2 + include/linux/list.h | 20 + include/linux/netdevice.h | 4 + include/linux/poison.h | 2 + include/net/page_pool/helpers.h | 8 +- include/net/page_pool/types.h | 10 + include/uapi/linux/netdev.h | 36 ++ net/core/Makefile | 2 +- net/core/netdev-genl-gen.c | 60 +++ net/core/netdev-genl-gen.h | 11 + net/core/page_pool.c | 69 ++- net/core/page_pool_priv.h | 12 + net/core/page_pool_user.c | 408 +++++++++++++++++ tools/include/uapi/linux/netdev.h | 36 ++ tools/net/ynl/generated/netdev-user.c | 419 ++++++++++++++++++ tools/net/ynl/generated/netdev-user.h | 171 +++++++ tools/net/ynl/lib/ynl.h | 2 +- tools/net/ynl/samples/.gitignore | 1 + tools/net/ynl/samples/Makefile | 2 +- tools/net/ynl/samples/page-pool.c | 147 ++++++ 25 files changed, 1574 insertions(+), 33 deletions(-) create mode 100644 net/core/page_pool_priv.h create mode 100644 net/core/page_pool_user.c create mode 100644 tools/net/ynl/samples/page-pool.c Tested-by: Daniel Golle