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From: Qi Zheng In-Reply-To: <69A13C1A.9020002@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 3D2CD40004 X-Stat-Signature: sdwrj8whm6yi9uymbsfh583twji3f9f4 X-Rspam-User: X-HE-Tag: 1772175029-895337 X-HE-Meta: U2FsdGVkX1+2tWZoLT9oksqYLlC5SzDEaDpFVtnj3nJ8ib+DsNIL3iq4AGHv8GySS77No5i4joT8M6Oh5HGVEfQUoGlxB1+Er4JcDmYcuPcIG0G/Ezo3p7OQIgbCvnvYk5Muti1qK28rHrtT+HlnBmipKIYdZpRJljSWlbcrGtOKel4F4LpKVjuSyhC2USDlHE81i8dM7UU7EAcXJuxDkr7Z13r+RqL547fFt1xMxafEJ67/WEaZ67Hf8mmLp9jEbHNqnMZ2rPw7EaBraOiMXJgA6vwnEupQ1W8kIaOj93Qx5ScqpnEXcMu/5r3SPWRj8mji3B+Mz2hh5636o63kqLkQGhO6wZdftxTKxa+iemv8Wmy2+PJp/VcfH/I4q2X3U7V2zMUYJ7d6KTmYwGI8bGEkZ72xcEWfCYv0Wt4Jzvh8Oyp2wtjfFz2mIQJBQNx9Q8hIfe8JfsyED952ptStR+VrqvI+1nPYPnP3QBb/7gv4pdMjh8HbMS8s7P1Fq/AIJ+7GutoQB2VXWqJjQZ3QVmBfABZhisZrwc6gwglamzPo4QQAP77GIx2lCwmRPIqVZ+U9czySzxAwvHKybp7TJ7jUZXMVMxgRBj/BZJE/WXpy4RbJa2f/mbOvSTkPaWFOt8NI9tO10yZ/JYTZDRGdK9JFThFKwet1h+rsnxnnjVpBFjJ3e+CMHyhE6zgg+b2pxMBPtfZgoPv88fylz4VzVQkGmCXcxw9qSgLov13oPH8lEZuawTbMxr3m7pf0lxz+EBtko9f//n1diwOeoD6yrhEjQ6DgLze0T92wFn1kcbiX/lvAScdUd4OA0ZgBRUbXW3XAVq/GmUDSY4tUkuPKenk8RoUrO1WxZIODcQuTL8dQ4hfl6BgqbjNuGT4sjJ9QfHDPoIgkctMOwcnqH8NBcAAUDWyxlrIFVI5uPS8ckVgMnkwDmOPRd9B3ZQPUFlBw3TN3QKtC9cmWYfySI1G BuW565V/ mctMnnnqvuk1qwBHl4ViMBRJHikCaUGwG/pyxTm1XkbwAQ5UeEJ/UKk1W+EYYnnOhtHESdCMo9jAUEG4g2cAuKr+29Pf886Bkhr2YE7+KCjPsqEvNgaCjB6aj4zyr4bqY/DQbDmUJ5HZf+bKRNUdUb0NnpQygEwyy8ZMjIRoRdbgbsocng09Emzv34UDU0Mt9RkaxEtB2kj1FwKptvlc1Wh0lsrTPuHWsiVbDW/5R08vkyEqCg0eKaX1c9GQtZyPe1DFmWRLw+WhM1TXfcMmMcgYmd1Tc/51guYSMDHTE4cFMxfpfEJ8btWdJiQZNI7uq/xowboMam08UwHrHB7NWFSCzjoPfSmzEZ7iF7v9l9nnJMC4WU8s6SHruUQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2/27/26 2:39 PM, yebin (H) wrote: > > > On 2026/2/27 11:31, Muchun Song wrote: >> >> >>> On Feb 27, 2026, at 10:55, Ye Bin wrote: >>> >>> From: Ye Bin >>> >>> In order to better analyze the issue of file system uninstallation >>> caused >>> by kernel module opening files, it is necessary to perform dentry >>> recycling >>> on a single file system. But now, apart from global dentry recycling, >>> it is >>> not supported to do dentry recycling on a single file system separately. >> >> Would shrinker-debugfs satisfy your needs (See Documentation/admin- >> guide/mm/shrinker_debugfs.rst)? >> >> Thanks, >> Muchun >> > Thank you for the reminder. The reclamation of dentries and nodes can > meet my needs. However, the reclamation of the page cache alone does not > satisfy my requirements. I have reviewed the code of > shrinker_debugfs_scan_write() and found that it does not support batch > deletion of all dentries/inode for all nodes/memcgs,instead, users need > to traverse through them one by one, which is not very convenient. Based > on my previous experience, I have always performed dentry/inode > reclamation at the file system level. Using shrinker-debugfs allows users to specify the size of a single reclaim cycle (nr_to_scan), which controls the strength of each reclaim cycle to adapt to different workloads. Can the new drop_fs_caches support a similar approach? Thanks, Qi > > Thanks, > Ye Bin >>> This feature has usage scenarios in problem localization scenarios.At >>> the >>> same time, it also provides users with a slightly fine-grained >>> pagecache/entry recycling mechanism. >>> This patchset supports the recycling of pagecache/entry for >>> individual file >>> systems. >>> >>> Diff v3 vs v2 >>> 1. Introduce introduce drop_sb_dentry_inode() helper instead of >>> reclaim_dcache_sb()/reclaim_icache_sb() helper for reclaim dentry/inode. >>> 2. Fixing compilation issues in specific architectures and >>> configurations. >>> >>> Diff v2 vs v1: >>> 1. Fix possible live lock for shrink_icache_sb(). >>> 2. Introduce reclaim_dcache_sb() for reclaim dentry. >>> 3. Fix potential deadlocks as follows: >>> https://lore.kernel.org/linux- >>> fsdevel/00000000000098f75506153551a1@google.com/ >>> After some consideration, it was decided that this feature would >>> primarily >>> be used for debugging purposes. Instead of adding a new IOCTL >>> command, the >>> task_work mechanism was employed to address potential deadlock issues. >>> >>> Ye Bin (3): >>>   mm/vmscan: introduce drop_sb_dentry_inode() helper >>>   sysctl: add support for drop_caches for individual filesystem >>>   Documentation: add instructions for using 'drop_fs_caches sysctl' >>>     sysctl >>> >>> Documentation/admin-guide/sysctl/vm.rst |  44 +++++++++ >>> fs/drop_caches.c                        | 125 ++++++++++++++++++++++++ >>> include/linux/mm.h                      |   1 + >>> mm/internal.h                           |   3 + >>> mm/shrinker.c                           |   4 +- >>> mm/vmscan.c                             |  50 ++++++++++ >>> 6 files changed, 225 insertions(+), 2 deletions(-) >>> >>> -- >>> 2.34.1 >>> >> >> . >>