[pve-devel] [PATCH qemu-server 1/1] Use nr_hugepages from /proc/cmdline
Kamil Trzciński
ayufan at ayufan.eu
Tue Feb 12 12:49:14 CET 2019
Currently Proxmox VE always deallocates HugePagesTLB
when starting a new machine and it makes it impossible
to preconfigure kernel /proc/cmdline with persistent allocation.
This changes makes deallocation to prefer defaults set by /proc/cmdline,
by parsing the cmdline and respecting hugepages= and hugepagesz=.
---
PVE/QemuServer/Memory.pm | 27 +++++++++++++++++++++++++--
1 file changed, 25 insertions(+), 2 deletions(-)
diff --git a/PVE/QemuServer/Memory.pm b/PVE/QemuServer/Memory.pm
index 0e4c830..aac4cf4 100644
--- a/PVE/QemuServer/Memory.pm
+++ b/PVE/QemuServer/Memory.pm
@@ -538,6 +538,29 @@ sub hugepages_allocate {
}
+sub hugepages_default_nr_hugepages {
+ my ($size) = @_;
+
+ my $cmdline = PVE::Tools::file_read_firstline("/proc/cmdline");
+ my $args = PVE::Tools::split_args($cmdline);
+
+ my $parsed_size = 2; # default is 2M
+
+ foreach my $arg (@$args) {
+ if ($arg eq "hugepagesz=2M") {
+ $parsed_size = 2;
+ } elsif ($arg eq "hugepagesz=1G") {
+ $parsed_size = 1024;
+ } elsif ($arg =~ m/^hugepages=(\d+)?$/) {
+ if ($parsed_size == $size) {
+ return $1;
+ }
+ }
+ }
+
+ return 0;
+}
+
sub hugepages_pre_deallocate {
my ($hugepages_topology) = @_;
@@ -545,8 +568,8 @@ sub hugepages_pre_deallocate {
my $hugepages_size = $size * 1024;
my $path = "/sys/kernel/mm/hugepages/hugepages-${hugepages_size}kB/";
- my $hugepages_nr = PVE::Tools::file_read_firstline($path."nr_hugepages");
- PVE::ProcFSTools::write_proc_entry($path."nr_hugepages", 0);
+ my $hugepages_nr = hugepages_default_nr_hugepages($size);
+ PVE::ProcFSTools::write_proc_entry($path."nr_hugepages", $hugepages_nr);
}
}
--
2.11.0
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