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CA-423172: Xen uses ~294 pages/vCPU, not 256 #6854

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Merged
edwintorok merged 2 commits into from
Jan 27, 2026
Merged

CA-423172: Xen uses ~294 pages/vCPU, not 256 #6854

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e2db96c
[maintenance]: fix formatting
edwintorok Jan 27, 2026
ec3bd4a
CA-423172: Xen uses ~294 pages/vCPU, not 256
edwintorok Jan 22, 2026
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4 changes: 2 additions & 2 deletions ocaml/squeezed/src/squeeze_xen.ml
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Expand Up @@ -60,8 +60,8 @@ let ( -* ) = Int64.sub

let mib = 1024L

(** Same as xen commandline *)
(** CA-423173: this is `low_mem_virq_limit` Xen, default 64MiB *)
(** Same as xen commandline
CA-423173: this is `low_mem_virq_limit` Xen, default 64MiB *)
let low_mem_emergency_pool = 64L ** mib

(** Return the extra amount we always add onto maxmem *)
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2 changes: 2 additions & 0 deletions ocaml/xapi-idl/memory/memory.ml
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Expand Up @@ -218,6 +218,8 @@ module Memory_model (D : MEMORY_MODEL_DATA) = struct
D.extra_internal_mib
+++ D.extra_external_mib
+++ shadow_mib static_max_mib vcpu_count multiplier
(* CA-423172: Xen uses some extra memory/vCPU *)
+++ mib_of_pages_used (38L *** Int64.of_int vcpu_count)
+++ D.shim_mib static_max_mib

let footprint_mib target_mib static_max_mib vcpu_count multiplier =
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