Chris Lu e1fa4ec756 perf(cache): drop OS page cache after disk cache reads (#9098) ...

* perf(cache): drop OS page cache after disk cache reads

After reading from the on-disk chunk cache, advise the kernel via
FADV_DONTNEED to release the corresponding page cache pages. This
prevents double-caching the same data in both user-space and kernel
page caches, freeing RAM for other uses on systems with large disk
caches.

* fix(cache): guard dropReadCache against zero length and invalid fd

A zero-length fadvise is interpreted as "to end of file" on Linux,
which would inadvertently drop the page cache for the entire remainder
of the cache volume. Also check fd >= 0 to avoid unnecessary syscalls
when the backend file is closed.

* perf(cache): only apply FADV_DONTNEED for reads >= 1 MiB

For small needle reads the syscall overhead outweighs the memory
savings, and the kernel page cache is more beneficial for warm data.
Restrict fadvise to reads of at least 1 MiB where the freed page
cache is meaningful.

2026-04-16 09:38:42 -07:00

..

memory_map

go fix

2026-02-20 18:42:00 -08:00

rclone_backend

go fix

2026-02-20 18:42:00 -08:00

s3_backend

chore: execute goimports to format the code (#7983)

2026-01-07 13:06:08 -08:00

backend.go

chore: execute goimports to format the code (#7983)

2026-01-07 13:06:08 -08:00

disk_file.go

perf(cache): drop OS page cache after disk cache reads (#9098)

2026-04-16 09:38:42 -07:00

volume_create_linux.go

go fix

2026-02-20 18:42:00 -08:00

volume_create_windows.go

go fix

2026-02-20 18:42:00 -08:00

volume_create.go

go fix

2026-02-20 18:42:00 -08:00