From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933663AbcHaIvU (ORCPT ); Wed, 31 Aug 2016 04:51:20 -0400 Received: from mga05.intel.com ([192.55.52.43]:19021 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759169AbcHaIuU (ORCPT ); Wed, 31 Aug 2016 04:50:20 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.30,261,1470726000"; d="c'?scan'208";a="1043816379" Subject: Re: DAX can not work on virtual nvdimm device To: Dan Williams References: <436d7526-bf06-633d-afce-4333552d9e31@linux.intel.com> <20160819183047.GA7216@linux.intel.com> <600ac51c-0f61-6e53-9bfa-669c85494d1f@linux.intel.com> <20160829193014.GB16738@linux.intel.com> <61d5c470-a8bf-86d5-d1fe-b4b577a85967@linux.intel.com> Cc: Ross Zwisler , Yumei Huang , KVM , "linux-nvdimm@lists.01.org" , "qemu-devel@nongnu.org" , LKML , Linux ACPI , Stefan Hajnoczi From: Xiao Guangrong Message-ID: <25098f37-53f7-6d5d-0b1a-8469bab51a9f@linux.intel.com> Date: Wed, 31 Aug 2016 16:44:47 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/mixed; boundary="------------3A4D28200E41E767DF1D9A84" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a multi-part message in MIME format. --------------3A4D28200E41E767DF1D9A84 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit On 08/31/2016 01:09 AM, Dan Williams wrote: > > Can you post your exact reproduction steps? This test is not failing for me. > Sure. 1. make the guest kernel based on your tree, the top commit is 10d7902fa0e82b (dax: unmap/truncate on device shutdown) and the config file can be found in this thread. 2. add guest kernel command line: memmap=6G!10G 3: start the guest: x86_64-softmmu/qemu-system-x86_64 -machine pc,nvdimm --enable-kvm \ -smp 16 -m 32G,maxmem=100G,slots=100 /other/VMs/centos6.img -monitor stdio 4: in guest: mkfs.ext4 /dev/pmem0 mount -o dax /dev/pmem0 /mnt/pmem/ echo > /mnt/pmem/xxx ./mmap /mnt/pmem/xxx ./read /mnt/pmem/xxx The source code of mmap and read has been attached in this mail. Hopefully, you can detect the error triggered by read test. Thanks! --------------3A4D28200E41E767DF1D9A84 Content-Type: text/x-csrc; name="read.c" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="read.c" #include #include #include #include #include #include int main(int argc, char *argv[]) { char *filename; if (argc < 2) { printf("arg: filename.\n"); return -1; } filename = argv[1]; printf("test on %s.\n", filename); int fd = open(filename, O_RDWR); if (fd < 0) { perror("open"); return -1; } int count = 0; while (1) { ssize_t ret; char buf; ret = read(fd, &buf, sizeof(buf)); if (ret < 0) { perror("READ"); return -1; } if (ret == 0) break; if (ret != sizeof(buf)) { printf("Count %x Ret %lx sizeof(buf) %lx.\n", count, ret, sizeof(buf)); return -1; } count++; printf("%c", buf); } printf("\n Good Read.\n"); return 0; } --------------3A4D28200E41E767DF1D9A84 Content-Type: text/x-csrc; name="mmap.c" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="mmap.c" #include #include #include #include #include #include #include static void write_test(char *buf, int size) { int i; printf("Try to write %p for %x size.\n", buf, size); for (i = 0; i < size; i++) buf[i] = (char)(i & 0xFF); printf("Write Done.\n"); } static void read_test(char *buf, int size) { int i; printf("Try to read %p for %x size.\n", buf, size); for (i = 0; i < size; i++) if (buf[i] != (char)(i & 0xFF)) { printf("Read Check failed.\n"); printf("Index %x, %c expect %x.\n", i, buf[i], i & 0xFF); exit(-1); } printf("Read Done.\n"); } static void fread_test(int fd, int size) { char buf; int i; i = lseek(fd, 0, SEEK_END); printf("End: %x.\n", i); i = lseek(fd, 0, SEEK_SET); if (i != 0) { perror("seek"); exit(-1); } printf("Try to fread fd=%d size %x sizeof(buf) %ld.\n", fd, size, sizeof(buf)); for (i = 0; i < size; i++) { int ret; ret = read(fd, &buf, sizeof(buf)); if (ret != sizeof(buf)) { printf("Read failed, offset %x, ret %d ftell %ld.\n", i, ret, lseek(fd, 0, SEEK_CUR)); perror("read"); exit(-1); } if (buf != (char)(i & 0xFF)) { printf("Read Check failed.\n"); printf("Index %x, %c expect %x.\n", i, buf, i & 0xFF); exit (-1); } } printf("Fread Done.\n"); } int main(int argc, char *argv[]) { char *filename; char *buf; int fd; if (argc < 2) { printf("arg: filename.\n"); return -1; } filename = argv[1]; printf("mmap test on %s.\n", filename); fd = open(filename, O_RDWR); if (fd < 0) { perror("open"); return -1; } if (lseek(fd, 0x1000, SEEK_SET) != 0x1000) { perror("seek"); return -1; } if (ftruncate(fd, 0x1000) != 0) { perror("ftruncate"); return -1; } // return 0; buf = mmap(NULL, 0x1000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); if (buf == MAP_FAILED) { perror("mmap"); return -1; } write_test(buf, 0x1000); read_test(buf, 0x1000); msync(buf, 0x1000, MS_SYNC); fread_test(fd, 0x1000); close(fd); return 0; } --------------3A4D28200E41E767DF1D9A84--