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([2409:8a28:e60:7d70:199a:6f05:bad8:24fd]) by smtp.gmail.com with ESMTPSA id u3-20020a17090a1d4300b001fb4a8d82a7sm4415394pju.56.2022.08.28.01.33.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 28 Aug 2022 01:33:36 -0700 (PDT) Message-ID: Date: Sun, 28 Aug 2022 16:33:24 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.2.0 Subject: Re: [PATCHSET v2 for-6.1] kernfs, cgroup: implement kernfs_show() and cgroup_file_show() Content-Language: en-US To: Tejun Heo , Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Johannes Weiner , Imran Khan , kernel-team@fb.com References: <20220828050440.734579-1-tj@kernel.org> From: Chengming Zhou In-Reply-To: <20220828050440.734579-1-tj@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/8/28 13:04, Tejun Heo wrote: > Hello, > > Greg: If this looks good to you, can you apply 0001-0008 to your tree? I'll > likely have more cgroup updates on top, so I think it'd be better if I pull > your tree and then handle the cgroup part in cgroup tree. > > Currently, deactivated kernfs nodes are used for two purposes - during > removal to kill and drain nodes and during creation to make multiple > kernfs_nodes creations to succeed or fail as a group. > > This patchset implements kernfs_show() which can dynamically show and hide > kernfs_nodes using the [de]activation mechanisms, and, on top, implements > cgroup_file_show() which allows toggling cgroup file visiblity. > > This is for the following pending patchset to allow disabling PSI on > per-cgroup basis: > > https://lore.kernel.org/all/20220808110341.15799-1-zhouchengming@bytedance.com/t/#u > > which requires hiding the corresponding cgroup interface files while > disabled. > > This patchset contains the following nine patches. > > 0001-kernfs-Simply-by-replacing-kernfs_deref_open_node-wi.patch > 0002-kernfs-Drop-unnecessary-mutex-local-variable-initial.patch > 0003-kernfs-Refactor-kernfs_get_open_node.patch > 0004-kernfs-Skip-kernfs_drain_open_files-more-aggressivel.patch > 0005-kernfs-Improve-kernfs_drain-and-always-call-on-remov.patch > 0006-kernfs-Add-KERNFS_REMOVING-flags.patch > 0007-kernfs-Factor-out-kernfs_activate_one.patch > 0008-kernfs-Implement-kernfs_show.patch > 0009-cgroup-Implement-cgroup_file_show.patch > > 0001-0003 are misc prep patches. 0004-0008 implement kernsf_deactivate(). > 0009 implements cgroup_file_show() on top. The patches are also available in > the following git branch: > > git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git kernfs-show > > The main difference from the previous version[1] is that while show/hide > still use the same mechanism as [de]activation, their states are tracked > separately so that e.g. an unrelated kernfs_activate() higher up in the tree > doesn't interfere with hidden nodes in the subtree. Hello, For this series: Reviewed-by: Chengming Zhou Tested-by: Chengming Zhou Thanks! > > diffstat follows. Thanks. > > fs/kernfs/dir.c | 102 +++++++++++++++++++++++++++++++---------------- > fs/kernfs/file.c | 151 +++++++++++++++++++++++++++++++++------------------------------------- > fs/kernfs/kernfs-internal.h | 1 > include/linux/cgroup.h | 1 > include/linux/kernfs.h | 3 + > kernel/cgroup/cgroup.c | 20 +++++++++ > 6 files changed, 166 insertions(+), 112 deletions(-) > > -- > tejun > > [1] http://lkml.kernel.org/r/20220820000550.367085-1-tj@kernel.org >