mirror of
https://github.com/seaweedfs/seaweedfs.git
synced 2026-05-28 12:41:15 +00:00
e1fa4ec756
* 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.
14 lines
442 B
Go
14 lines
442 B
Go
//go:build linux
|
|
|
|
package util
|
|
|
|
import "golang.org/x/sys/unix"
|
|
|
|
// DropOSPageCache advises the kernel that the given byte range is no longer
|
|
// needed in the page cache. This is useful after reading from a user-space
|
|
// cache (e.g., on-disk chunk cache) to prevent the kernel from double-caching
|
|
// the same data.
|
|
func DropOSPageCache(fd int, offset int64, length int64) error {
|
|
return unix.Fadvise(fd, offset, length, unix.FADV_DONTNEED)
|
|
}
|