From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f198.google.com (mail-qk0-f198.google.com [209.85.220.198]) by kanga.kvack.org (Postfix) with ESMTP id E753F440874 for ; Wed, 12 Jul 2017 14:06:14 -0400 (EDT) Received: by mail-qk0-f198.google.com with SMTP id e123so13254111qkd.14 for ; Wed, 12 Jul 2017 11:06:14 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id m45si2933612qtc.254.2017.07.12.11.06.13 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 12 Jul 2017 11:06:13 -0700 (PDT) From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= Subject: [PATCH 0/5] Cache coherent device memory (CDM) with HMM v4 Date: Wed, 12 Jul 2017 14:06:02 -0400 Message-Id: <20170712180607.2885-1-jglisse@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: John Hubbard , David Nellans , Dan Williams , Balbir Singh , Michal Hocko , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= Changes since v3: - change name to device host (s/DEVICE_PUBLIC/DEVICE_HOST/) - added comments about how such memory is accounted (rss and memcg) - added a documentation patch (to explain rss and memcg choice) - add proper include to migrate.c and drop #if/#endif - fix missing #if/#endif so this works even if DEVICE_PRIVATE is not enabled Git tree: https://cgit.freedesktop.org/~glisse/linux/log/?h=hmm-cdm-v4 Cache coherent device memory apply to architecture with system bus like CAPI or CCIX. Device connected to such system bus can expose their memory to the system and allow cache coherent access to it from the CPU. Even if for all intent and purposes device memory behave like regular memory, we still want to manage it in isolation from regular memory. Several reasons for that, first and foremost this memory is less reliable than regular memory if the device hangs because of invalid commands we can loose access to device memory. Second CPU access to this memory is expected to be slower than to regular memory. Third having random memory into device means that some of the bus bandwith wouldn't be available to the device but would be use by CPU access. This is why we want to manage such memory in isolation from regular memory. Kernel should not try to use this memory even as last resort when running out of memory, at least for now. This patchset add a new type of ZONE_DEVICE memory (DEVICE_HOST) that is use to represent CDM memory. This patchset build on top of the HMM patchset that already introduce a new type of ZONE_DEVICE memory for private device memory (see HMM patchset). The end result is that with this patchset if a device is in use in a process you might have private anonymous memory or file back page memory using ZONE_DEVICE (DEVICE_HOST). Thus care must be taken to not overwritte lru fields of such pages. Hence all core mm changes are done to address assumption that any process memory is back by a regular struct page that is part of the lru. ZONE_DEVICE page are not on the lru and the lru pointer of struct page are use to store device specific informations. Thus this patchset update all code path that would make assumptions about lruness of a process page. patch 01 - add DEVICE_HOST type to ZONE_DEVICE (all core mm changes) patch 02 - add an helper to HMM for hotplug of CDM memory patch 03 - preparatory patch for memory controller changes (memch) patch 04 - update memory controller to properly handle ZONE_DEVICE pages when uncharging patch 05 - documentation patch Previous posting: v1 https://lkml.org/lkml/2017/4/7/638 v2 https://lwn.net/Articles/725412/ v3 https://lwn.net/Articles/727114/ JA(C)rA'me Glisse (5): mm/device-host-memory: device memory cache coherent with CPU v3 mm/hmm: add new helper to hotplug CDM memory region v2 mm/memcontrol: allow to uncharge page without using page->lru field mm/memcontrol: support MEMORY_DEVICE_PRIVATE and MEMORY_DEVICE_HOST v2 mm/hmm: documents how device memory is accounted in rss and memcg Documentation/vm/hmm.txt | 40 ++++++++ fs/proc/task_mmu.c | 2 +- include/linux/hmm.h | 7 +- include/linux/ioport.h | 1 + include/linux/memremap.h | 21 +++++ include/linux/mm.h | 20 ++-- kernel/memremap.c | 17 +++- mm/Kconfig | 11 +++ mm/gup.c | 7 ++ mm/hmm.c | 89 ++++++++++++++++-- mm/madvise.c | 2 +- mm/memcontrol.c | 231 ++++++++++++++++++++++++++++++----------------- mm/memory.c | 46 +++++++++- mm/migrate.c | 57 +++++++----- mm/swap.c | 11 +++ 15 files changed, 431 insertions(+), 131 deletions(-) -- 2.13.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org