From patchwork Wed Oct 9 01:58:57 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Daisuke Matsuda (Fujitsu)" X-Patchwork-Id: 13827435 Received: from esa9.hc1455-7.c3s2.iphmx.com (esa9.hc1455-7.c3s2.iphmx.com [139.138.36.223]) (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 BFAFC18EAD; Wed, 9 Oct 2024 02:00:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=139.138.36.223 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728439228; cv=none; b=qeMr+lNwyJuvidc7tPxXa9RZBnpSk/QS2yTFj85uQzvLXzEwGMMy/E1eFDuryik+U6SV0ecj0QAQGCr0eBZ05GLHKAW58iCZINua72TgY6hSbMT4PfY3vPG+29c03aP5aUM2zoTLhmJaJUQFSkE3z2YRz8ftYb7tSWWb2KDUKcM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728439228; c=relaxed/simple; bh=RfWz65TO9O+3EygdWlvs5IcxQ/DrHJ7T1WojUeZUkNk=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=i99YelYxdvSCd02oYUhP2SU90iDOf7xr92pXXe3Ecs+7C22/uz0CVY9rZak5KbaTNYrYI+gwov7ypFerQJ8KISlrbfZVlYWX8Gh48dfV0OyBrYQEZXoW7YEl8EWZpNHsVR9+pvyddfMuuocrQbHQ5i19tWohThfmCi1uEi8LtKs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=fujitsu.com; spf=pass smtp.mailfrom=fujitsu.com; dkim=pass (2048-bit key) header.d=fujitsu.com header.i=@fujitsu.com header.b=FCgI7tt7; arc=none smtp.client-ip=139.138.36.223 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=fujitsu.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=fujitsu.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=fujitsu.com header.i=@fujitsu.com header.b="FCgI7tt7" DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=fujitsu.com; i=@fujitsu.com; q=dns/txt; s=fj2; t=1728439226; x=1759975226; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=RfWz65TO9O+3EygdWlvs5IcxQ/DrHJ7T1WojUeZUkNk=; b=FCgI7tt761Ep5lLDqBzVWffD9Mid0J1yDlm0JQO0k8ZxIkdLEvBqaWwe wcwjNTp46wYcurkXnnVzV03TvaopYGmLzZEORAhVxhHBeAeUlerHDDqRQ O+oowr6yZLt976XmhB10AUiAo3lxiGHf+OVWEYLllc5KyoWYGsB8q7F3V tGwZsyztHYG1SzbYY7xqsBFGkqLth25zUNeZ2x9uCxR1aSzyY5dUfTMY/ S6HxLQIL+JS2jA8XPNP/rp240tDIwNF0zEsOmMyRioAMS6/2jN4Q0VKrD eBFGPx6f8CSsLnbqoMTpdBtTvb8zjsH2rd2W7RANGTt/e2qhQpcjNxLpT Q==; X-CSE-ConnectionGUID: bFhX2FDITvu2JfntAcgNRQ== X-CSE-MsgGUID: E9fVxAiMRSOcGi1LQFo/Ig== X-IronPort-AV: E=McAfee;i="6700,10204,11219"; a="164552971" X-IronPort-AV: E=Sophos;i="6.11,188,1725289200"; d="scan'208";a="164552971" Received: from unknown (HELO oym-r1.gw.nic.fujitsu.com) ([210.162.30.89]) by esa9.hc1455-7.c3s2.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2024 10:59:14 +0900 Received: from oym-m4.gw.nic.fujitsu.com (oym-nat-oym-m4.gw.nic.fujitsu.com [192.168.87.61]) by oym-r1.gw.nic.fujitsu.com (Postfix) with ESMTP id 2DFEED29E6; Wed, 9 Oct 2024 10:59:12 +0900 (JST) Received: from m3004.s.css.fujitsu.com (m3004.s.css.fujitsu.com [10.128.233.124]) by oym-m4.gw.nic.fujitsu.com (Postfix) with ESMTP id 711E1D531D; Wed, 9 Oct 2024 10:59:11 +0900 (JST) Received: from sm-x86-stp01.ssoft.mng.com (unknown [10.124.178.20]) by m3004.s.css.fujitsu.com (Postfix) with ESMTP id 27E832005340; Wed, 9 Oct 2024 10:59:11 +0900 (JST) From: Daisuke Matsuda To: linux-rdma@vger.kernel.org, leon@kernel.org, jgg@ziepe.ca, zyjzyj2000@gmail.com Cc: linux-kernel@vger.kernel.org, rpearsonhpe@gmail.com, lizhijian@fujitsu.com, Daisuke Matsuda Subject: [PATCH for-next v8 0/6] On-Demand Paging on SoftRoCE Date: Wed, 9 Oct 2024 10:58:57 +0900 Message-Id: <20241009015903.801987-1-matsuda-daisuke@fujitsu.com> X-Mailer: git-send-email 2.39.1 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-TM-AS-GCONF: 00 This patch series implements the On-Demand Paging feature on SoftRoCE(rxe) driver, which has been available only in mlx5 driver[1] so far. This series has been blocked because of the hang issue of srp 002 test[2], which was believed to be caused after applying the commit 9b4b7c1f9f54 ("RDMA/rxe: Add workqueue support for rxe tasks"). My patches are dependent on the commit because the ODP feature requires sleeping in kernel space, and it is impossible with the former tasklet implementation. According to the original reporter[3], the hang issue is already gone in v6.10. Additionally, tasklet is marked deprecated[4]. I think the rxe driver is ready to accept this series since there is no longer any reason to consider reverting back to the old tasklet. I omitted some contents like the motive behind this series from the cover- letter. Please see the cover letter of v3 for more details[5]. [Overview] When applications register a memory region(MR), RDMA drivers normally pin pages in the MR so that physical addresses are never changed during RDMA communication. This requires the MR to fit in physical memory and inevitably leads to memory pressure. On the other hand, On-Demand Paging (ODP) allows applications to register MRs without pinning pages. They are paged-in when the driver requires and paged-out when the OS reclaims. As a result, it is possible to register a large MR that does not fit in physical memory without taking up so much physical memory. [How does ODP work?] "struct ib_umem_odp" is used to manage pages. It is created for each ODP-enabled MR on its registration. This struct holds a pair of arrays (dma_list/pfn_list) that serve as a driver page table. DMA addresses and PFNs are stored in the driver page table. They are updated on page-in and page-out, both of which use the common interfaces in the ib_uverbs layer. Page-in can occur when requester, responder or completer access an MR in order to process RDMA operations. If they find that the pages being accessed are not present on physical memory or requisite permissions are not set on the pages, they provoke page fault to make the pages present with proper permissions and at the same time update the driver page table. After confirming the presence of the pages, they execute memory access such as read, write or atomic operations. Page-out is triggered by page reclaim or filesystem events (e.g. metadata update of a file that is being used as an MR). When creating an ODP-enabled MR, the driver registers an MMU notifier callback. When the kernel issues a page invalidation notification, the callback is provoked to unmap DMA addresses and update the driver page table. After that, the kernel releases the pages. [Supported operations] All traditional operations are supported on RC connection. The new Atomic write[6] and RDMA Flush[7] operations are not included in this patchset. I will post them later after this patchset is merged. On UD connection, Send, Recv, and SRQ-Recv are supported. [How to test ODP?] There are only a few resources available for testing. pyverbs testcases in rdma-core and perftest[8] are recommendable ones. Other than them, the ibv_rc_pingpong command can also be used for testing. Note that you may have to build perftest from upstream because old versions do not handle ODP capabilities correctly. The latest ODP tree is available from github: https://github.com/ddmatsu/linux/tree/odp_v8 [Future work] My next work is to enable the new Atomic write[6] and RDMA Flush[7] operations with ODP. After that, I am going to implement the prefetch feature. It allows applications to trigger page fault using ibv_advise_mr(3) to optimize performance. Some existing software like librpma[9] use this feature. Additionally, I think we can also add the implicit ODP feature in the future. [1] Understanding On Demand Paging (ODP) https://enterprise-support.nvidia.com/s/article/understanding-on-demand-paging--odp-x [2] [bug report] blktests srp/002 hang https://lore.kernel.org/linux-rdma/dsg6rd66tyiei32zaxs6ddv5ebefr5vtxjwz6d2ewqrcwisogl@ge7jzan7dg5u/T/ [3] blktests failures with v6.10-rc1 kernel https://lore.kernel.org/linux-block/wnucs5oboi4flje5yvtea7puvn6zzztcnlrfz3lpzlwgblrxgw@7wvqdzioejgl/ [4] [00/15] ethernet: Convert from tasklet to BH workqueue https://patchwork.kernel.org/project/linux-rdma/cover/20240621050525.3720069-1-allen.lkml@gmail.com/ [5] [PATCH for-next v3 0/7] On-Demand Paging on SoftRoCE https://lore.kernel.org/lkml/cover.1671772917.git.matsuda-daisuke@fujitsu.com/ [6] [PATCH v7 0/8] RDMA/rxe: Add atomic write operation https://lore.kernel.org/linux-rdma/1669905432-14-1-git-send-email-yangx.jy@fujitsu.com/ [7] [for-next PATCH 00/10] RDMA/rxe: Add RDMA FLUSH operation https://lore.kernel.org/lkml/20221206130201.30986-1-lizhijian@fujitsu.com/ [8] linux-rdma/perftest: Infiniband Verbs Performance Tests https://github.com/linux-rdma/perftest [9] librpma: Remote Persistent Memory Access Library https://github.com/pmem/rpma v7->v8: 1) Dropped the first patch because the same change was made by Bob Pearson. cf. https://github.com/torvalds/linux/commit/23bc06af547f2ca3b7d345e09fd8d04575406274 2) Rebased to 6.12.1-rc2 v6->v7: 1) Rebased to 6.6.0 2) Disabled using hugepages with ODP 3) Addressed comments on v6 from Jason and Zhu cf. https://lore.kernel.org/lkml/cover.1694153251.git.matsuda-daisuke@fujitsu.com/ v5->v6: Fixed the implementation according to Jason's suggestions cf. https://lore.kernel.org/all/ZIdFXfDu4IMKE+BQ@nvidia.com/ cf. https://lore.kernel.org/all/ZIdGU709e1h5h4JJ@nvidia.com/ v4->v5: 1) Rebased to 6.4.0-rc2+ 2) Changed to schedule all works on responder and completer to workqueue v3->v4: 1) Re-designed functions that access MRs to use the MR xarray. 2) Rebased onto the latest jgg-for-next tree. v2->v3: 1) Removed a patch that changes the common ib_uverbs layer. 2) Re-implemented patches for conversion to workqueue. 3) Fixed compile errors (happened when CONFIG_INFINIBAND_ON_DEMAND_PAGING=n). 4) Fixed some functions that returned incorrect errors. 5) Temporarily disabled ODP for RDMA Flush and Atomic Write. v1->v2: 1) Fixed a crash issue reported by Haris Iqbal. 2) Tried to make lock patters clearer as pointed out by Romanovsky. 3) Minor clean ups and fixes. Daisuke Matsuda (6): RDMA/rxe: Make MR functions accessible from other rxe source code RDMA/rxe: Move resp_states definition to rxe_verbs.h RDMA/rxe: Add page invalidation support RDMA/rxe: Allow registering MRs for On-Demand Paging RDMA/rxe: Add support for Send/Recv/Write/Read with ODP RDMA/rxe: Add support for the traditional Atomic operations with ODP drivers/infiniband/sw/rxe/Makefile | 2 + drivers/infiniband/sw/rxe/rxe.c | 18 ++ drivers/infiniband/sw/rxe/rxe.h | 37 ---- drivers/infiniband/sw/rxe/rxe_loc.h | 39 ++++ drivers/infiniband/sw/rxe/rxe_mr.c | 34 +++- drivers/infiniband/sw/rxe/rxe_odp.c | 282 ++++++++++++++++++++++++++ drivers/infiniband/sw/rxe/rxe_resp.c | 18 +- drivers/infiniband/sw/rxe/rxe_verbs.c | 5 +- drivers/infiniband/sw/rxe/rxe_verbs.h | 37 ++++ 9 files changed, 419 insertions(+), 53 deletions(-) create mode 100644 drivers/infiniband/sw/rxe/rxe_odp.c