Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752843AbdFOSRZ (ORCPT ); Thu, 15 Jun 2017 14:17:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:44126 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751016AbdFOSRY (ORCPT ); Thu, 15 Jun 2017 14:17:24 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A4EF7214D7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=fail smtp.mailfrom=shli@fb.com From: Shaohua Li To: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Cc: tj@kernel.org, gregkh@linuxfoundation.org, hch@lst.de, axboe@fb.com, rostedt@goodmis.org, lizefan@huawei.com, Kernel-team@fb.com, Shaohua Li Subject: [PATCH V3 00/12] blktrace: output cgroup info Date: Thu, 15 Jun 2017 11:17:08 -0700 Message-Id: X-Mailer: git-send-email 2.11.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3245 Lines: 76 From: Shaohua Li Hi, Currently blktrace isn't cgroup aware. blktrace prints out task name of current context, but the task of current context isn't always in the cgroup where the BIO comes from. We can't use task name to find out IO cgroup. For example, Writeback BIOs always comes from flusher thread but the BIOs are for different blk cgroups. Request could be requeued and dispatched from completely different tasks. MD/DM are another examples. This brings challenges if we want to use blktrace for performance tunning with cgroup enabled. This patchset try to fix the gap. We print out cgroup fhandle info in blktrace. Userspace can use open_by_handle_at() syscall to find the cgroup by fhandle. Or userspace can use name_to_handle_at() syscall to find fhandle for a cgroup and use a BPF program to filter out blktrace for a specific cgroup. The first 6 patches adds export operation handlers for kernfs, so userspace can use open_by_handle_at/name_to_handle_at to a kernfs file. Later patches make blktrace output cgroup info. Last post tries to make inode number 64-bit, but actually we can't simply make it 64-bit because inode number must be 32-bit in 32 bit systems. So I switch back to use 32-bit inode and change the policy for i_generation accounting, which should avoid conflict. Sorry for the noise. Thanks, Shaohua V2 -> V3: - Uses 32 bits inode number - Refresh to latest -next tree V1 -> V2: - Fix a bug in cgroup association - Fix build errors reported by 0day - Address some issues pointed out by Tejun Shaohua Li (12): kernfs: use idr instead of ida to manage inode number kernfs: implement i_generation kernfs: add an API to get kernfs node from inode number kernfs: don't set dentry->d_fsdata kernfs: introduce kernfs_node_id kernfs: add exportfs operations cgroup: export fhandle info for a cgroup blktrace: export cgroup info in trace block: always attach cgroup info into bio block: call __bio_free in bio_endio blktrace: add an option to allow displying cgroup path block: use standard blktrace API to output cgroup info for debug notes arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 2 +- block/bfq-iosched.h | 13 +- block/bio-integrity.c | 1 + block/bio.c | 2 + block/blk-throttle.c | 13 +- block/cfq-iosched.c | 15 +- fs/kernfs/dir.c | 108 ++++++++++--- fs/kernfs/file.c | 10 +- fs/kernfs/inode.c | 9 +- fs/kernfs/kernfs-internal.h | 9 ++ fs/kernfs/mount.c | 96 ++++++++++-- fs/kernfs/symlink.c | 6 +- fs/sysfs/mount.c | 2 +- include/linux/blk-cgroup.h | 17 +- include/linux/blktrace_api.h | 13 +- include/linux/cgroup.h | 16 +- include/linux/kernfs.h | 23 ++- include/uapi/linux/blktrace_api.h | 3 + kernel/cgroup/cgroup.c | 15 +- kernel/trace/blktrace.c | 259 ++++++++++++++++++++++--------- 20 files changed, 458 insertions(+), 174 deletions(-) -- 2.9.3