Post Syndicated from original https://lwn.net/Articles/890025/

Filesystems and the virtual filesystem layer are in the business of
managing files that actually exist, but the Linux “dentry cache”, which
remembers the results of file-name lookups, also keeps track of files that
don’t exist. This cache of “negative dentries” plays an important
role in the overall performance of the system but, if it is allowed to grow
too large, its role can become negative in its own right. As the 2022 Linux Storage, Filesystem,
and Memory-Management Summit (LSFMM) approaches, the subject of negative
dentries has come up yet again; whether one can be positive about the
prospects for a resolution this time around remains unclear.