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(unknown [120.245.2.88]) by mr85p00im-zteg06011501.me.com (Postfix) with ESMTPSA id BE46E480EFF; Wed, 12 Jan 2022 14:35:40 +0000 (UTC) From: sxwjean@me.com To: akpm@linux-foundation.org, david@redhat.com, mhocko@suse.com, dan.j.williams@intel.com, osalvador@suse.de, naoya.horiguchi@nec.com, thunder.leizhen@huawei.com Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Xiongwei Song Subject: [PATCH v3 0/2] Add support for getting page info of ZONE_DEVICE by /proc/kpage* Date: Wed, 12 Jan 2022 22:35:15 +0800 Message-Id: <20220112143517.262143-1-sxwjean@me.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Proofpoint-Virus-Version: =?utf-8?q?vendor=3Dfsecure_engine=3D1=2E1=2E170-?= =?utf-8?q?22c6f66c430a71ce266a39bfe25bc2903e8d5c8f=3A6=2E0=2E425=2C18=2E0?= =?utf-8?q?=2E790=2C17=2E0=2E607=2E475=2E0000000_definitions=3D2022-01-12=5F?= =?utf-8?q?04=3A2022-01-11=5F01=2C2022-01-12=5F04=2C2020-04-07=5F01_signatur?= =?utf-8?q?es=3D0?= X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=528 bulkscore=0 malwarescore=0 mlxscore=0 adultscore=0 clxscore=1015 suspectscore=0 phishscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2201120095 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 2E7AB40017 X-Stat-Signature: b9jdiw57xdabokaby1igcx8tb81t3nuy Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=me.com header.s=1a1hai header.b=Je5Lm8Ej; spf=pass (imf01.hostedemail.com: domain of sxwjean@me.com designates 17.58.23.182 as permitted sender) smtp.mailfrom=sxwjean@me.com; dmarc=pass (policy=quarantine) header.from=me.com X-HE-Tag: 1641998160-33991 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Xiongwei Song Patch 1 is adding pfn_to_devmap_page() function to get page of ZONE_DEVICE by pfn. It checks if dev_pagemap is valid, if yes, return page pointer. Patch 2 is finishing supporting /proc/kpage* in exposing pages info of ZONE_DEVICE to userspace. The unit test has been done by "page-types -r", which ran in qemu with the below arguments: -object memory-backend-file,id=mem2,share,mem-path=./virtio_pmem.img,size=2G -device virtio-pmem-pci,memdev=mem2,id=nv1 , which is used to emulate pmem device with 2G memory space. As we know, the pages in ZONE_DEVICE are only set PG_reserved flag. So before the serires, run "page-types -r", the result is: flags page-count MB symbolic-flags long-symbolic-flags 0x0000000100000000 24377 95 ___________________________r________________ reserved , which means the only PG_reserved set of pages in system wide have 24377. run "cat /proc/zoneinfo" to get the ZONE_DEVICE info: Node 1, zone Device pages free 0 boost 0 min 0 low 0 high 0 spanned 0 present 0 managed 0 cma 0 protection: (0, 0, 0, 0, 0) After this series, run "page-types -r", the result is: flags page-count MB symbolic-flags long-symbolic-flags 0x0000000100000000 548665 2143 ___________________________r________________ reserved , which means the only PG_reserved set of pages in system wide have 548665. Run "cat /proc/zoneinfo" to get the ZONE_DEVICE info: Node 1, zone Device pages free 0 boost 0 min 0 low 0 high 0 spanned 524288 present 0 managed 0 cma 0 protection: (0, 0, 0, 0, 0) , these added pages number is 524288 in ZONE_DEVICE as spanned field showed. Meanwhile, we can do 548665 - 24377 = 524288 that is increment of the reserved pages, it equals to the spanned field of ZONE_DEVICE. Hence it looks like the patchset works well. v2 -> v3: * Before returning page pointer, check validity of page by pgmap_pfn_valid(). https://lkml.org/lkml/2022/1/10/853 . v1 -> v2: * Take David's suggestion to simplify the implementation of pfn_to_devmap_page(). Please take a look at https://lkml.org/lkml/2022/1/10/320 . Xiongwei Song (2): mm/memremap.c: Add pfn_to_devmap_page() to get page in ZONE_DEVICE proc: Add getting pages info of ZONE_DEVICE support fs/proc/page.c | 35 ++++++++++++++++++++------------- include/linux/memremap.h | 8 ++++++++ mm/memremap.c | 42 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 72 insertions(+), 13 deletions(-)