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// This file is part of dpdk. It is subject to the license terms in the COPYRIGHT file found in the top-level directory of this distribution and at https://raw.githubusercontent.com/lemonrock/dpdk/master/COPYRIGHT. No part of predicator, including this file, may be copied, modified, propagated, or distributed except according to the terms contained in the COPYRIGHT file.
// Copyright © 2017 The developers of dpdk. See the COPYRIGHT file in the top-level directory of this distribution and at https://raw.githubusercontent.com/lemonrock/dpdk/master/COPYRIGHT.


/// Transparent Huge Page (THP) shared memory ('shmem') choice.
///
/// Used for at least:-
///
/// * SysV SHM
/// * memfds,
/// * shared anonymous mmaps (of /dev/zero or `MAP_ANONYMOUS`)
/// * GPU drivers' DRM objects
/// * Ashmem
#[derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
pub enum TransparentHugePageSharedMemoryChoice
{
	/// Never allocate.
	Never,
	
	/// Always use.
	Always,
	
	/// Only allocate huge page if it will be fully within 'i_size'.
	///
	/// Also for pages so specified by the `madvise()` (or `fadvise()`) syscall with the `MADV_HUGEPAGE` flag.
	WithinSize,
	
	/// Only for pages so specified by the `madvise()` (or `fadvise()`) syscall with the `MADV_HUGEPAGE` flag.
	Advise,
	
	/// For use in emergencies, to force the huge option off from all mounts.
	Deny,
	
	/// Force the huge option on for all (very useful for testing).
	Force,
}

impl TransparentHugePageSharedMemoryChoice
{
	#[inline(always)]
	pub(crate) fn to_value(self) -> &'static str
	{
		use self::TransparentHugePageSharedMemoryChoice::*;
		
		match self
		{
			Never => "never",
			Always => "always",
			WithinSize => "within_size",
			Advise => "advise",
			Deny => "deny",
			Force => "force",
		}
	}
}