pub(crate) unsafe fn dontneed(ptr: *mut u8, len: usize)Available on Unix and crate feature
pool only.Expand description
Releases the physical pages of the page-aligned subrange of
[ptr, ptr + len), keeping the virtual range mapped.
§Safety
The range must lie within a live mapping exclusively owned by the caller, with no outstanding references into it. After the call the range’s contents are undefined: Linux replaces them with zero pages, but other systems (macOS in particular) may keep the old bytes resident, so callers must fully overwrite the range before reading it again.