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authorDavid Hildenbrand <david@redhat.com>2022-10-14 15:47:19 +0200
committerDavid Hildenbrand <david@redhat.com>2022-10-27 11:01:03 +0200
commite6816458624813de4a31f89096a620b410e1c2b8 (patch)
tree327eb49230110c949e5443ebae4d1fd64336acf8 /qapi/qom.json
parente04a34e55cf1911099e2d8a680f9bee4f6d90e4a (diff)
hostmem: Allow for specifying a ThreadContext for preallocation
Let's allow for specifying a thread context via the "prealloc-context" property. When set, preallcoation threads will be crated via the thread context -- inheriting the same CPU affinity as the thread context. Pinning preallcoation threads to CPUs can heavily increase performance in NUMA setups, because, preallocation from a CPU close to the target NUMA node(s) is faster then preallocation from a CPU further remote, simply because of memory bandwidth for initializing memory with zeroes. This is especially relevant for very large VMs backed by huge/gigantic pages, whereby preallocation is mandatory. Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Message-Id: <20221014134720.168738-7-david@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com>
Diffstat (limited to 'qapi/qom.json')
-rw-r--r--qapi/qom.json4
1 files changed, 4 insertions, 0 deletions
diff --git a/qapi/qom.json b/qapi/qom.json
index 20b5735d78..87fcad2423 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -578,6 +578,9 @@
#
# @prealloc-threads: number of CPU threads to use for prealloc (default: 1)
#
+# @prealloc-context: thread context to use for creation of preallocation threads
+# (default: none) (since 7.2)
+#
# @share: if false, the memory is private to QEMU; if true, it is shared
# (default: false)
#
@@ -608,6 +611,7 @@
'*policy': 'HostMemPolicy',
'*prealloc': 'bool',
'*prealloc-threads': 'uint32',
+ '*prealloc-context': 'str',
'*share': 'bool',
'*reserve': 'bool',
'size': 'size',