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kopia/cli
Julio López d886957c7d feat(snapshots): reduce kernel page-cache pressure during snapshots (#5437)
Add fadvise hints to backup read path to reduce OS cache pollution

Issue FADV_SEQUENTIAL at open and FADV_DONTNEED at close for every file read during backup. This tells the kernel to read-ahead aggressively and then reclaim pages once the file is fully consumed, reducing cache pressure from large backups without adding measurable overhead.

Uses SyscallConn().Control() instead of os.File.Fd() to avoid switching file descriptors to blocking mode, which would remove them from Go's epoll poller and stall the upload pipeline.

Incremental FADV_DONTNEED during reads was tested and removed — it adds ~15% overhead on large-file workloads by fighting the kernel's own LRU. Restore write-path cache eviction was also tested and not included.

Authored-by: Rajat Gupta rajat.gupta@veeam.com
2026-06-26 19:29:13 -07:00
..
2021-05-03 10:28:00 -07:00
2024-01-11 18:02:31 -08:00