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Add memory.ml from xen-api/xenopsd/squeezed
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‎memory/memory.ml‎

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(*
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* Copyright (C) 2006-2009 Citrix Systems Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published
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* by the Free Software Foundation; version 2.1 only. with the special
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* exception on linking described in file LICENSE.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*)
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(** Functions relating to memory requirements of Xen domains *)
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let ( +++ ) = Int64.add
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let ( --- ) = Int64.sub
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let ( *** ) = Int64.mul
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let ( /// ) = Int64.div
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(* === Memory conversion factors ============================================ *)
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let bytes_per_kib = 1024L
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let bytes_per_mib = 1048576L
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let bytes_per_page = 4096L
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let kib_per_page = bytes_per_page /// bytes_per_kib
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let kib_per_mib = 1024L
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let pages_per_mib = bytes_per_mib /// bytes_per_page
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(* === Arithmetic functions ================================================= *)
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(** Returns true if (and only if) the specified argument is a power of 2. *)
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let is_power_of_2 n =
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(n > 0) && (n land (0 - n) = n)
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let round_down_to_multiple_of x y =
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(x /// y) *** y
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let round_up_to_multiple_of x y =
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((x +++ y --- 1L) /// y) *** y
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(* === Memory rounding functions ============================================ *)
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let round_up = round_up_to_multiple_of
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let round_down = round_down_to_multiple_of
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let round_bytes_down_to_nearest_page_boundary v = round_down v bytes_per_page
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let round_bytes_down_to_nearest_mib v = round_down v bytes_per_mib
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let round_kib_down_to_nearest_page_boundary v = round_down v kib_per_page
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let round_kib_up_to_nearest_page_boundary v = round_up v kib_per_page
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let round_kib_up_to_nearest_mib v = round_up v kib_per_mib
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let round_pages_up_to_nearest_mib v = round_up v pages_per_mib
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(* === Division functions =================================================== *)
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let divide_rounding_down numerator denominator =
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numerator /// denominator
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let divide_rounding_up numerator denominator =
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(numerator +++ denominator --- 1L) /// denominator
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(* === Memory unit conversion functions ===================================== *)
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let bytes_of_kib value = value *** bytes_per_kib
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let bytes_of_pages value = value *** bytes_per_page
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let bytes_of_mib value = value *** bytes_per_mib
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let kib_of_mib value = value *** kib_per_mib
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let kib_of_pages value = value *** kib_per_page
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let pages_of_mib value = value *** pages_per_mib
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let kib_of_bytes_free value = divide_rounding_down value bytes_per_kib
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let pages_of_bytes_free value = divide_rounding_down value bytes_per_page
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let pages_of_kib_free value = divide_rounding_down value kib_per_page
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let mib_of_bytes_free value = divide_rounding_down value bytes_per_mib
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let mib_of_kib_free value = divide_rounding_down value kib_per_mib
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let mib_of_pages_free value = divide_rounding_down value pages_per_mib
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let kib_of_bytes_used value = divide_rounding_up value bytes_per_kib
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let pages_of_bytes_used value = divide_rounding_up value bytes_per_page
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let pages_of_kib_used value = divide_rounding_up value kib_per_page
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let mib_of_bytes_used value = divide_rounding_up value bytes_per_mib
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let mib_of_kib_used value = divide_rounding_up value kib_per_mib
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let mib_of_pages_used value = divide_rounding_up value pages_per_mib
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(* === Domain memory breakdown ============================================== *)
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(* ╤ ╔══════════╗ ╤ *)
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(* │ ║ shadow ║ │ *)
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(* │ ╠══════════╣ │ *)
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(* overhead │ ║ extra ║ │ *)
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(* │ ║ external ║ │ *)
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(* │ ╠══════════╣ ╤ │ *)
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(* │ ║ extra ║ │ │ *)
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(* │ ║ internal ║ │ │ *)
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(* ╪ ╠══════════╣ ╤ │ │ footprint *)
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(* │ ║ video ║ │ │ │ *)
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(* │ ╠══════════╣ ╤ ╤ │ actual │ xen │ *)
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(* │ ║ ║ │ │ │ / │ maximum │ *)
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(* │ ║ ║ │ │ │ target │ │ *)
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(* │ ║ guest ║ │ │ build │ / │ │ *)
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(* │ ║ ║ │ │ start │ total │ │ *)
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(* static │ ║ ║ │ │ │ │ │ *)
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(* maximum │ ╟──────────╢ │ ╧ ╧ ╧ ╧ *)
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(* │ ║ ║ │ *)
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(* │ ║ ║ │ *)
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(* │ ║ balloon ║ │ build *)
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(* │ ║ ║ │ maximum *)
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(* │ ║ ║ │ *)
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(* ╧ ╚══════════╝ ╧ *)
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(* === Domain memory breakdown: HVM guests ================================== *)
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module type MEMORY_MODEL_DATA = sig
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val extra_internal_mib : int64
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val extra_external_mib : int64
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end
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module HVM_memory_model_data : MEMORY_MODEL_DATA = struct
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let extra_internal_mib = 1L
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let extra_external_mib = 1L
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end
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module Linux_memory_model_data : MEMORY_MODEL_DATA = struct
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let extra_internal_mib = 0L
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let extra_external_mib = 1L
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end
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type memory_config = {
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build_max_mib : int64;
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build_start_mib : int64;
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xen_max_mib : int64;
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shadow_mib : int64;
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required_host_free_mib : int64;
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}
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module Memory_model (D : MEMORY_MODEL_DATA) = struct
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let build_max_mib static_max_mib video_mib = static_max_mib --- (Int64.of_int video_mib)
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let build_start_mib target_mib video_mib = target_mib --- (Int64.of_int video_mib)
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let xen_max_offset_mib = D.extra_internal_mib
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let xen_max_mib target_mib = target_mib +++ xen_max_offset_mib
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let shadow_mib static_max_mib vcpu_count multiplier =
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let vcpu_pages = 256L *** (Int64.of_int vcpu_count) in
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let p2m_map_pages = static_max_mib in
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let shadow_resident_pages = static_max_mib in
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let total_mib = mib_of_pages_used
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(vcpu_pages +++ p2m_map_pages +++ shadow_resident_pages) in
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let total_mib_multiplied =
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Int64.of_float ((Int64.to_float total_mib) *. multiplier) in
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max 1L total_mib_multiplied
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let overhead_mib static_max_mib vcpu_count multiplier =
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D.extra_internal_mib +++
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D.extra_external_mib +++
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(shadow_mib static_max_mib vcpu_count multiplier)
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let footprint_mib target_mib static_max_mib vcpu_count multiplier =
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target_mib +++ (overhead_mib static_max_mib vcpu_count multiplier)
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let shadow_multiplier_default = 1.0
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let full_config static_max_mib video_mib target_mib vcpus shadow_multiplier =
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{
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build_max_mib = build_max_mib static_max_mib video_mib;
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build_start_mib = build_start_mib target_mib video_mib;
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xen_max_mib = xen_max_mib static_max_mib;
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shadow_mib = shadow_mib static_max_mib vcpus shadow_multiplier;
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required_host_free_mib = footprint_mib target_mib static_max_mib vcpus shadow_multiplier;
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}
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end
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module HVM = Memory_model (HVM_memory_model_data)
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module Linux = Memory_model (Linux_memory_model_data)
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