From 4bb4a2732e097cd20594bab9039fcba9fac0b31f Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Thu, 30 May 2019 10:33:19 +0200 Subject: [PATCH] numa: deprecate implict memory distribution between nodes Implicit RAM distribution between nodes has exactly the same issues as: "numa: deprecate 'mem' parameter of '-numa node' option" only with QEMU being the user that's 'adding' 'mem' parameter. Deprecate it, to get it out of the way so that we could consolidate guest RAM allocation using memory backends making it consistent and possibly later on transition to using memory devices instead of adhoc memory mapping for the initial RAM. Signed-off-by: Igor Mammedov Message-Id: <1559205199-233510-4-git-send-email-imammedo@redhat.com> Signed-off-by: Eduardo Habkost --- hw/core/numa.c | 3 +++ qemu-deprecated.texi | 8 ++++++++ 2 files changed, 11 insertions(+) diff --git a/hw/core/numa.c b/hw/core/numa.c index b9e79b8c8b..cb5fdbcb1e 100644 --- a/hw/core/numa.c +++ b/hw/core/numa.c @@ -405,6 +405,9 @@ void numa_complete_configuration(MachineState *ms) if (i == nb_numa_nodes) { assert(mc->numa_auto_assign_ram); mc->numa_auto_assign_ram(mc, numa_info, nb_numa_nodes, ram_size); + warn_report("Default splitting of RAM between nodes is deprecated," + " Use '-numa node,memdev' to explictly define RAM" + " allocation per node"); } numa_total = 0; diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi index ba52999f7f..4a626f535d 100644 --- a/qemu-deprecated.texi +++ b/qemu-deprecated.texi @@ -104,6 +104,14 @@ In future new machine versions will not accept the option but it will still work with old machine types. User can check QAPI schema to see if the legacy option is supported by looking at MachineInfo::numa-mem-supported property. +@subsection -numa node (without memory specified) (since 4.1) + +Splitting RAM by default between NUMA nodes has the same issues as @option{mem} +parameter described above with the difference that the role of the user plays +QEMU using implicit generic or board specific splitting rule. +Use @option{memdev} with @var{memory-backend-ram} backend or @option{mem} (if +it's supported by used machine type) to define mapping explictly instead. + @section QEMU Machine Protocol (QMP) commands @subsection block-dirty-bitmap-add "autoload" parameter (since 2.12.0)